EXCAVATIONS, PLASTER AND CALIBRATION INVESTIGATIONS, MISRA YANTRA, JANTAR MANTAR, NEW DELHI

REPORT ON THE PRELIMINARY WORKS, MISRA YANTRAJANTAR MANTAR, NEW DELHI

PART I

EXCAVATIONS, PLASTER AND CALIBRATION INVESTIGATIONSFEBRUARY- JUNE 2007

PREPARED BYANISHA SHEKHAR MUKHERJI

JULY 2007

CONTENTS

BACKGROUND P1INTRODUCTION P2 - 4

DETAILS OF THE INVESTIGATIONS

1. SELECTIVE MASONRY AND PLASTER INVESTIGATIONS P 5-72. SELECTIVE EXCAVATIONS P 8-10

3. SELECTIVE CALIBRATION INVESTIGATIONS P 11-12

OVERALL RECOMMENDATIONS P 13-14

PHOTOGRAPHIC DOCUMENTATION OF PRELIMINARY INVESTIGATIONS:1 MARCH 2007 P 15-1716 MARCH 2007 P 18-2611 APRIL 2007 P 27-32

ANNEXURES P 33ANNEXURE 1 PHOTOGRAPH OF DRAINS IN GREAT SAMRAT, JAIPUR P 34

ANNEXURE 2 LIST OF SUITABLE TREES P 35-36ANNEXURE 3 PLAN AND ELEVATION SHOWING LOCATION OF TRENCH EXCAVATIONS P 37

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1820 BRAHMAPUTRA APARTMENTS SECTOR 29 NOIDA 201301 PH: 9810085787; 0120 3247715email: [email protected]; anisha @worksofteam.com

BACKGROUND:

It is the functional aspect of the Yantras within the Jantar Mantar Observatory—the reason for its unusual architecture, and a continuing means of accurately observing and studying stellar phenomenon—which invests both the site and the area around it with an unique importance. Accordingly, the Conservation Philosophy adopted for the Observatory complex, is ‘conserving and clarifying the function and form of the astronomical instruments, to increase its perceived and actual value’.1 The fi rst Yantra to be taken up for full-scale physical conservation as part of this philosophy is the Misra Yantra. Since Jai Singh’s observatory is a part of—and probably the last visible link with—the old school of astronomy that defi ned astronomical phenomenon through unaided eye observations, the restoration exercise must reinstate the ability of the yantras to allow observations with the naked eye. As is known, the structure of the Misra Yantra contains fi ve instruments of astronomy. As is also known, the exact method of using most of these instruments has been hitherto unknown—it is neither historically documented nor is there suffi cient fi eld research. Hence, the importance of the joint research and fi eld studies (since 2004) between practitioners of astronomy and conservation in deciding the use and accuracy of the different parts of the Yantra. The fi rst part of the Yantra projected to be restored to functioning ability is the Misra Samrat —consisting of two quadrants and two gnomons. This research is evidently a necessary part of authentic conservation. Additionally, the absence of any accurate measured or condition drawings of the Yantra, and the past programme of maintenance which disregarded its astronomy aspect, has meant that masonry parameters have been changed from the original and many of the markings are obliterated or incorrect. In many cases, because of uneven or incorrect plastering, it has not been possible to take consistent or sustained astronomy readings. This has necessarily increased the time allotted for the fi eld studies. As part of the preparatory work prior to starting physical conservation on the Yantra, the following preliminary works have already been done or are underway:i) detailed condition and measured surveys2;ii) material analysis3;iii) fi eld research on the possible range and accuracy of astronomy observations4;iv) detailed photo and other documentation of the markings. In keeping with conservation guidelines, the effort is to uncover the original, not to ‘improve’ it. Therefore, if Jai Singh’s original masonry construction is found to be not absolutely symmetrical or perpendicular, this is to be documented (using the Condition and Measured Survey of the Misra Yantra 2003 as a base drawing) and retained as such. At the same time, if there is evidence to show that the Yantra’s original structure or functioning elements have been obscured in later interventions, then these are to be reinstated and restored to the extent possible.

1. Jantar Mantar Feasibilty Report 1999, Anisha Shekhar Mukherji, p. 42.

2. Misra Yantra Condition and Measured Survey Report, Anisha Shekhar Mukherji, August 2003

3. ASI Materials Testing Laboratory Analysis Report, 2001

4. Preliminary Report on the Calibration of the Jantar Mantar Instruments, Dr N Rathnashree, 2006

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INTRODUCTION

The excavations and other fi eld studies at the Misra Yantra, Jantar Mantar, New Delhi are part of the necessary preliminary investigations that comprise the preparatory works for the conservation of the above Yantra. This is in accordance with internationally accepted conservation practices. Thus, the Burra charter specifi cally states that ‘Work on a place must be preceded by professionally prepared studies of the physical, documentary and other evidence, and the existing fabric recorded before any intervention in the place’.1 In a series of site inspections and meetings from February (26.02.2007) to July (05.07.2007), a Committee2 has been meeting regularly (weekly or bi-monthly) at the Jantar Mantar to supervise and document the investigations, as well as to discuss the method, sequence and time-schedule of the conservation work for the Misra Yantra.

Preliminary Investigations and Studies:The preliminary investigations so far have essentially comprised of the following:

1. Selective masonry and plaster investigations;2. Selective excavations to ascertain foundation and ground-profi le

details; 3. Selective calibration investigations with respect to the Misra Samrat.

The excavations and plaster investigations have been conducted by the ASI staff on site under the supervision of Shri H. S. Negi, while the calibration and accuracy of masonry-parameter investigations have been conducted by a team of students and astronomers under the supervision of Dr N. Rathnashree. These investigations are particularly important in light of the fact that the masonry parameters as well as the external and internal ground levels of the Misra Yantra have, over the years, been changed from the original, and many of its calibrations are obliterated or incorrect. The site investigations with respect to foundation details and plaster/mortar compositions of the Yantra fl oors/walls, were started in the last week of February 2007. Trenches at selective positions in and around the Yantra were excavated for this purpose. According to the ASI offi cials, this is the fi rst time that excavation work of this nature has been done for the Misra Yantra. This work was slated to be fi nished by end April 2007, including documentation. However, part of the documentation work is still underway. CAD drawings, recording the dimensions of plinths, drains and masonry profi les revealed in the excavations, are under preparation by the ASI draftspersons and surveyors, using as their base the drawings prepared3 for the Measured and Condition Survey conducted in 2003. These drawings have undergone several rounds of checking4 by the Conservation Consultant and ASI offi cials, and inconsistencies or inaccuracies revealed in this checking are being corrected and incorporated in the CAD drawings of the relevant plans, sections and elevations. The site investigations with respect to the calibration parameters were started in April 2007. These investigations essentially consist of studying the shadow behaviour of the Yantra everyday, on a minute by minute basis from morning till evening.

1 The Australia ICO-MOS Charter for the Conservation of Places of Cultural Signifi cance, (The Burra Charter) Article 23.

2 Comprising of the following members, as constituted vide Offi ce Memorandum, F. No. DLH-25/2006-M-11422, dated 02/03/2007, from SA ASI: Shri A.K. Sinha, SA ASI; Dr. Rath-nashree, Dir. Nehru Planetarium; Shri Daljeet Singh, Deputy SA ASI; Shri Gurcharan Singh, ASAE (Asst. Supt. Archaeological Engr); Shri S. S. Saini, Deputy SAE (retd); Shri HS Negi, Con-servation Asst. ASI; Ms Anisha Shekhar Mukherji, Conservation Consultant.The following have also participated in some meetings: Senior Surveyor ASI, Shri Batra, ASI Draftspersons, Shri Majumdar, Shri Naushad Alam.

3 Plans, elevations and sections from Misra Yantra Condition and Measured Survey Report, Anisha Shekhar Mukherji, August 2003.

4 See Minutes of 9.03.2007; 16.03.2007; 11.04.2007; 18.04.2007; 3.05.2007; 30.05.2007. As noted in Minutes of 30 May 2007, ‘There were certain details that were inaccurate or missing, and some information was not noted correctly. For example, plans and sectional elevations of some trenches were not co-relating, such as the excavation trench between the Agra Yantra and the West Misra Samrat dial; in the long excavation trench along the East-ern Misra Samrat Gnomon, the ex-cavated plinth face was not shown at all in the sectional elevation; the drawing of the foundation-trench on the inner Misra Eastern Arch was incomplete.’

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This is the fi rst time in history since the Yantra’s construction that such a detailed study of its shadow movements is being done.5 These studies will help to ascertain the range and scope of the astronomy observations possible with the Yantra, and their relevance in today’s age. They were initially projected to be done for a period of 10 days, but diffi culties of shadow observations due to diffused light (because of unseasonal weather and the presence of clouds), irregularities in masonry surfaces and extremely high temperatures, has led to an extended schedule. Along with the investigations, the preparation of a full-size template for accurate time-calibrations (which are almost completely obliterated) of the Misra Samrat dials is being prepared on site. The above studies are imperative to comprehend the dimensions of the Observatory’s cultural signifi cance, and to formulate conservation approaches compatible to its cultural signifi cance.6

Simultaneously with such studies, lecture-demonstrations for visitors, students and other citizens of Delhi have been organised by the Nehru Planetarium, the Delhi Amateur Astronomers Association and the NGO S.P.A.C.E with some amount of fi nancial, logistical and administrative support, as and when applicable, from the ASI, NCF and Apeejay Surrendra Park Hotels. This support is an extension of one of the stated objectives of the Jantar Mantar Project, which is to increase awareness of, and appreciation for the Observatory. The response from the public to such interactions explaining the meaning and motive of the Yantras has been extraordinary —it has been observed that the number of visitors on such days is many more times than on ordinary days. The amount of time that visitors spend in understanding the Yantras is also far longer than they normally do. This response of the public proves an important conservation principle —that no matter how well-maintained and pleasant a historical site is, fi nally people will only fl ock to it if they can understand and appreciate how that historical site originally functioned and appeared. This report consists of the results of the above investigations, as well as their larger bearing on the constructional system, original appearance and functioning of the Misra Yantra, and the consequent implications on its proposed conservation method. It also contains the essence of Dr Rathnashree and her team’s investigations insofar as their direct bearing to the Yantra’s functional restoration is concerned. Additionally, a detailed report on calibration investigations and the astronomy data-collection, is being compiled by Dr Rathnashree; while the archaeological aspect of the excavations and other related investigations, would be part of a separate report by the ASI. It must be mentioned here, that part of the preliminary research identifi ed in earlier communications,7 was the examination of historical records such as archival photographs in possession of the ASI, and citings of previous conservation work in the ASI Manuals. This is still pending, and the relevant photographic evidence from this period is awaited. It needs to be emphasized that is imperative to examine all historical records to see what documentary evidence there is of original calibrations as well as to ascertain when major restoration/alteration/conservation activity was undertaken on the Yantra and the range of such activity. This is an essential part of good conservation practice8.

With respect to the conservation manuals, specifi cally the details

THE SPECIAL NIGHT-VIEWING EVENT HELD ON JUNE 18 2007 AT

THE OBSERVATORY TO INCREASE AWARENESS ABOUT THE YANTRAS

7 See Minutes of PIC Meeting dated 1 March 2007, pt. 6, ’The ASI Delhi Circle would photocopy relevant archival and past information, on the dials in particular and the Yantra in general, comprising of archival photo-albums, textual references in ASI manuals and yearly depart-ment reports, in time for the next site meeting of 9 March 2007.’See also Minutes of PIC Mtg. 16 March 2007, 11 April, 3 May 3007.

8 Article 23, The Burra Charter. Also see Articles 2, 4 and 5, The Burra Charter.

5 Dr V.N.Sharma, the only other scholar in recent times to observationally study the shadow movements of the Misra Yantra, has done so only for certain times of the day. Sawai Jai Singh and His Astronomy, pp.112-9, 1995, Motilal Banarsidass Publish-ers Pvt. Ltd.

6 See Article 14. Burra Charter, ‘Restoration should reveal anew culturally signifi cant aspects of the place’.

OBSERVATIONAL CALIBRATIONS ON SAMRAT YANTRA TO CHECK ITS

ACCURACY, 22 DECEMBER 2006

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required are those in Indian Archaeology–A Review, especially of the years 1920 (when measured drawings and photographs of the Jantar Mantar are recorded to have been done); 1975-6 (when the fl ooring of Misra Yantra was repaired); early 1950s (when work was done on the Niyat Chakras); 1978-79 (when the graduations of the Misra Yantra were restored). Additionally, details of the Annual Progress Report of the Superintendent, Archaeological Survey of India, Northern Circle, Muhammadan and British Monuments (year ending March 31st 1920), Zafar Hasan’s Listing of 1911, as well as records of conservation work carried out at the Observatory Complex in the years between 1920 and 1959 are also required. The photographic records to be looked up are those from the 1850s (when the Archaeological Society of Delhi fi rst took up the conservation of the Jantar Mantar); 1910-1911 (before the major conservation exercise predating the Coronation Durbar of 1911); 1916 (coinciding with G.R. Kaye’s visit to the Observatory), and the early 1950s when extensive restoration work was carried out on the Misra Yantra. Since such photographs or details of the conservation manuals, have not been obtained from the ASI as yet therefore, the present report does not contain any aspect or discussion on such archival investigations. These would form part of another report (Part II of the Preliminary Investigations on the Misra Yantra) as and when the necessary information has been received from the ASI. It need hardly be emphasized that this information needs to come in urgently.

Additionally, detailed macro-photo documentation of the calibrated surfaces of the Yantra was also identifi ed as a necessary precursor to the conservation work. Shri Sachdeva, Senior Photographer ASI Delhi Circle, has taken some photographs for the macro photo-documentation of the Yantras and dials of the Misra Yantra. Since Shri Ravindra, Photographer Central ASI Offi ce, has already documented the Dakshinottara Bhitti and the Misra Samrat Dials in January 2007, Shri Sachdeva would need to only photograph the remaining markings, viz. the Niyat Chakra Dials, the Karka Rasi Vilaya, and the Agra Yantra dials.

DETAILS OF INVESTIGATIONS(carried out from February to June 2007)

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The details of the investigations at the Misra Yantra so far are listed below.

1. Selective masonry and plaster investigations: At present the Yantra has a coating of snowcem (cement based external paint) over a layer of base plaster covering the masonry. This is evidently a later application. The information in the records of the ASI indicates that the Yantras were fi rst given a coat of dull terracotta colour in 1961-62, and coats of water-proof cement paint in 1992-3.1 In earlier spot investigations, mortar and plaster samples had been taken from selected parts of the Yantra and tested by the ASI Materials Testing Laboratory.2 These investigations revealed the presence of later layers of cement-based plasters over an earlier lime-pozzolanic mix plaster. However, the investigations were unable to state the exact composition of the original lime-plaster or the relative proportions of its components. It was therefore considered advisable to conduct some more investigations on site at this stage over a larger area, to ascertain if possible the composition and mix of original plaster and the depth at which original render/plaster may be found. The area taken up in the fi rst stage of the investigations was a one metre wide stretch of wall (on the East Samrat Gnomon). The snowcem layer was carefully sandpapered; however, being a cement based paint, it adhered very strongly to the underlying plaster. Since the removal of the snowcem layer could cause damage to the base plaster/masonry, it was decided to conduct the investigation on a much smaller area of about 6 inches by 9 inches. Cement based plaster was found underneath the snowcem layer. In view of the unseasonal rains as well as the high visitor movement past the east wall, further investigations were shifted to alternative wall areas within the inner faces of the Yantra, generally inaccessible to the public and with some measure of protection from the rain. The locations for this area were identifi ed as a) under the central arch of the Misra Yantra courtyard or b) under the entrance arch of the east ground-fl oor room of the Yantra; or c) the west-facing wall of the west courtyard. These investigations were to be confi ned to a wall area of 30 centimetres by 30 centimetres, located at least 1 metre above the fl oor level. This would ensure that even in the event of unexpected rain, water would not penetrate the uncovered masonry. In these sample wall areas, it was found that the later cement plaster had adhered so strongly to the underlying porous lime-plaster layer that the removal of the cement plaster caused the lime-plaster to fl ake off. The wall areas where the investigations were conducted were seen to be constructed of random rubble masonry in lime mortar. Thus, in none of the wall areas under investigation, were samples of intact original plaster found. Given the extensive reworking of the external wall surfaces in cement plaster, it seemed unlikely that evidence of intact lime plaster/mortar would be found here. Conclusion:

In view of the results of the above, it appears that it shall not be

1 Indian Archaeology 1961-62—A Review, Ed. A Ghosh, DG ASI 1964, New Delhi p. 127; Indian Archaeology 1992-3—A Review, Ed. Ajai Shankar, DG ASI 1997, p. 163

2 ASI Analysis Report of Mortar Samples, prepared by ASI Materials Testing Labora-tory, Appendix E-Annexure to Condition and Measured Survey Report, Anisha Shekhar Mukherji, August 2003

PLASTER INVESTIGATIONS ON SELECTED AREAS OF THE MISRA

YANTRA

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possible to obtain information about the composition of the original lime plaster from investigations on the Yantra. Thus, to arrive at an appropriate quality of lime-plaster that would give adequate protection to the external walls of the Yantra, and would provide precise edges and surfaces for accurate observations, it would be necessary to prepare samples of lime-plaster on site with differing proportions of components to check which is the most suitable for application at the Yantra. These samples would need to be prepared and left on site to see the effect of weathering on them, and would also need to be applied on masonry shapes which can simulate the effect of shadow measurements to check accuracy of astronomy observations. It is known that medieval builders could prepare and apply lime-plaster with different degrees of hardness and smoothness. In fact, a special water-proof plaster (saruj) was prepared especially for areas which required additional protection, such as surfaces of tanks or city walls. The composition and application process differed based on the purpose and the type of building for which the plaster was applied. Historical records indicate that lime mortar was used in the construction of Jai Singh’s Yantras. It is specifi cally mentioned in the Atharal-Sanadid, by Sir Syed Ahmed Khan (fi rst published in 1846, with a second abridged edition in 1854) of the Jantar Mantar that “Its various instruments were made of stone and lime mortar....”.3 Pandit Jagannath (Maharaja Sawai Jai Singh’s chief astronomer) in his instructions for constructing the yantras, also cites lime mortar as a constituent. In his instructions for Ram Yantra in the treatise Samrat Siddhant, he writes ‘Construct a surface of lime mortar and stone...’4 and for the Samrat, ‘...make its edges strong and smooth with lime plaster or stone’.5 The Misra Yantra, was constructed after Jai Singh’s time, and is neither mentioned in the list of instruments prepared by Pandit Jagananth nor are any construction procedures for it recorded by him. However, it may be reasonable to assume that the method of construction followed by Maharaja Madho Singh’s team was similar to that of the earlier Yantras made by his father. G.R. Kaye additionally notes in his report prepared in 1918 that ‘The Misra Yantra graduations are all in lime plaster...’.6 Though some researchers advocate relaying the graduations on a white stone surface such as marble, this seems inappropriate since historical evidence specifi cally mentions lime. Additionally, the veined and translucent surface of marble actually impedes shadow readings, which are the main method of using the Yantras. Field studies by scholars in recent times, clearly prove this. Dr V.N.Sharma writes of the Jaipur Observatory ‘The diffi culty of the penumbra becomes compounded...when the shadow falls on the grey areas of the marble of the quadrants of the Great Samrat’, and that ‘...on the white marble surface, the shadow of the gnomon edge cast by the weak orange-yellow rays of the morning sun was not distinct.’7 In Dr Rathnashree’s words ‘From a practical observational point of view, a material with a texture and colour such as matt white paper is the most appropriate.8 Fine lime render is the closest material that can simulate such an appearance, and would appear to be thus, most suitable for inscribing markings on the Yantras. A few travellers in the late eighteenth and nineteenth centuries (such as William Hunter in 1799) have recorded that the Samrat Yantra’s edges were in ‘white marble’.9 Leopold Von Orlich in his record of 1843 even mentions ‘handsome winding marble staircases’.10 However, their

INTRICATE PATTERNS IN LIME PLASTER CARVED BY MEDIEVAL BUILDERS STILL EXTANT TODAY

3 See English translation, titled Monuments of Delhi, ‘Histori-cal Study, R. Nath, Indian Institute of Islamic Studies, New Delhi, Monuments of the Post-Aurangzi-bian Period’, p. 67.

4 Siddhana-samrat, ed. Murlidhar Chaturveda, Sagar University, 1976 p. 39; as quoted in Sawai Jai Singh and his Astronomy, V.N. Sharma, Motilal Banarisdass Publishers Private Limited, New Delhi 1995, p. 83.

5 Ibid. p.8 as quoted by V.N. Sharma in Sawai Jai Singh and his Astronomy, Motilal Banarisdass Publishers Private Limited, New Delhi 1995, p. 42.

6 The Astronomical Observatories of Jai Singh, G.R.Kaye, ASI New Imperial Series, Vol.XL, 1918; Reprint, New Delhi 1982, p. 50.

7 See Sawai Jai Singh and his Astronomy, V.N. Sharma, p. 139 and p. 140

8 Dr. Rathnashree’s comments, Minutes of site Meeting, 9 January 2007.

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accounts should not be taken as the gospel truth, since some observations of these travellers have been seen to be faulty, and a combination of hearsay and conjecture. Thus G.R.Kaye notes ‘The account is not reliable and, I am inclined to think Von Orlich never visited the Observatory; but what he says is the sort of thing that occurs in many guide books.’11

It must also be remembered that all these travellers were from a different culture than the one in which Jai Singh’s Observatories were created, and therefore inevitably made errors of observation and conclusion. Hunter would have certainly not been the fi rst to make such errors of judgement. More than a hundred years before him, Jean Tavernier recorded that the Diwan-i-Am in the Red Fort of Shahjahanabad was covered in white marble. In fact, the Diwan-i-Am was in red sandstone—but covered by ‘layers of fi ne chunam or white plaster that even rivalled marble in its brilliance and whiteness’!12 Gordon Sanderson, the offi cer in charge of the fi rst major archaeological investigations in the Fort in the early 1900s, also recorded the fact that both the facades of the Diwan-i-Am were covered in white shell plaster ‘polished like the brightness of morning’.13

Additionally, there is the historical fact that the Delhi Observatory was the fi rst of all the Jantar Mantars, while the Misra Yantra was the fi rst and only yantra of its kind. There was a certain amount of experimentation inherent in its construction. It is thus, likely that the last layer on the Yantra’s masonry would have been of slow-setting lime plaster —the recipe for which may have included items like molasses and pulses, to achieve a surface where experimentation with calibrations was possible.14 Since it set slowly, any errors could be smoothened out and corrected. And since it hardened with exposure to moisture and air, the calibrations once made, were fi xed. This technique was also used by medieval builders to carve astonishingly precise patterns and sculptural motifs on ceilings and walls. Lime plaster may also be applied in layers which would have allowed some amount of trial and error on the part of the medieval astronomers, mathematicians and masons in their calculations and inscriptions. Contrastively in stone, the inscriptions once carved, cannot be erased easily without damage to the stone. Thus, available historical evidence, practical observational experience, and suitability of inscribing calibrations, support the choice of fi ne lime render (of a requisite whiteness and smoothness) as the most appropriate material for calibration.

2. Selective excavations to ascertain foundation and ground-profi le details: Excavation trenches were excavated sequentially at eight locations on the external face of the Yantra and fi ve locations in the internal spaces of the Yantra (including one within a ground-fl oor room). The

9 As mentioned in The Astronomical Observatories of Jai Singh, G.R.Kaye, 1918; p. 47.

10 Ibid.p. 48.

11 Ibid.p. 48.

12 The Red Fort of Shahjahanabad, Anisha Shekhar Mukherji, Oxford University press, 2003, p. 135.See also pp.5-6 for a discussion on the nature of perception and communication; and pp. 23 and 135 for descriptions of the Diwan-i-Am by travellers as opposed to the reality.

13 Delhi Fort, A Guide to the Buildings and Gardens, fi rst published Delhi 1914, Asian Educational Services Reprint 2000.

14 See Building Construction in Mughal India: The Evidence from Painting, Ahsan Jan Qaisar, OUP 1988

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external trenches were excavated in a L-shaped plan-profi le in order to examine the corner detail of the wall and its base. The internal trenches were rectangular, since wall positions at junctions could naturally not be disturbed. (See attached drawings in Annexure) Trial trenches were fi rst excavated at two locations, one on the north-east corner of the Misra Yantra (adjacent to the KarkaRasa Vilaya and Dakshinottara Bhitti) and the second on the south-west corner (between the West Misra Samrat Gnomon and the West Misra Samrat Dial). It was observed that the present ground level appears to be 15 to 17 inches above the original ground level. At the south-west corner, the remains of a storm-water drain were also observed. Six more trenches were excavated by 9.03.2007. Thus, the profi le at the four corners of the Yantra as well as some additional locations were visible—their photographs (before and after) are kept in the site offi ce. These revealed the presence of a base plinth on the eastern, western and northern faces of the Misra Yantra —along the Dakshinottara Bhitti and East Samrat Gnomon walls, as well as along the West Samrat Gnomon and KarkaRasi Valaya. Its dimensions vary slightly over different excavated areas; the measured survey of these by the ASI Delhi Circle records the dimensions. Base plinths were however not observed on part of the northern face of the Misra Yantra. Thus, the profi le and presence of the plinth here is not so clear. The excavations also revealed storm-water drains at varying depths running along the outer periphery, adjacent to the East and West faces of the Misra Yantra along the length of the gnomons and the East face of the East Misra Samrat Dial. These do not appear to be present along the North and South faces of the Misra Yantra. The trial trenches (temporarily covered with plywood and plastic to protect them against the unseasonal heavy rains over 12th to 14th March) were thereafter extended at certain locations. Traces of lime fl oor were observed in the section facing North, of the trench at the Yantra’s North-East corner (adjacent to the Karka Rasa Vilaya and Dakshinottara Bhitti), indicating the original fi nished ground level. This was observed to be at a depth of approximately 40 centimetres from the present external fi nished fl oor level around these Yantras. In the trench under the north arched-recess on the inner east wall, excavated to the foundation level, the depth of the foundation was observed to be about 7 feet (212 centimetres) from the present fl oor level of the arched recess. A single offset was observed at 2 feet 2 inches (66 centimetres) from the present fl oor level. The details of this excavated trench have been noted by the ASI draftpersons. The Bench-mark for recording the excavated levels was taken as the base of the two free-standing pillars south-west of the Misra Yantra. After the relevant photographic documentation of the trenches by the Delhi ASI Circle, the external open-to-sky trenches were covered.

Conclusion:

The presence of a projecting plinth face of about 15 inches depth, bounded by a surface drain at places, makes it appear that the original ground level immediately around the Misra Yantra was much lower than the present ground-level. The change in the ground level might have resulted because of repeated re-laying of the ground surface in

EXCAVATED TRENCH, INNER FACE OF EASTERN SAMRAT GNOMON, MISRA YANTRA: DETAIL OF FOUNDATION

EXCAVATED TRENCH 1: EASTERN-NORTHERN WALL JUNCTION, MISRA YANTRA. NOTE THE PROJECTING

PLINTH

EXCAVATED TRENCH 2: WESTERN FACE

EXCAVATED TRENCH : WESTERN END OF KARKARASI VALAYA (NORTH FACADE)

EXCAVATED TRENCH AND PLINTH: WEST SAMRAT GNOMON (WEST FACADE)

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maintenance work down the years. Studies by astronomers and researchers seem to point to a similar conclusion. For instance, V. N.Sharma, in his scholarly book on Jai Singh’s Observatories, notes that

‘With this Dakshinottara Bhitti, the procedure for measuring the altitude of a planet or star, which does not cast any discernible shadow, is cumbersome at best, because the instrument is too close to the ground to facilitate an easy reading.’(Italics mine)15

Thus, on the basis of the evidence of the excavations backed by the practical neccessities of using the Yantra for astronomy readings, it seems likely that originally the Yantra was not so close to the ground. However, in the spot excavations, the plinth face was not observed to be present on the south face of the Yantra. Therefore, it needs to be checked both by investigation of earlier documentation and archival-records as well as further selective excavations, whether the base plinth is an original feature or a later addition. It might also be that different areas around the Yantra were at different depths. This is a possibility, if we consider the profi le of other Yantras in the Observatory, such as the Great Samrat Yantra, which has its north ground level higher than the south. It also appears from Dr Rathnashree’s researches that the Dakshinottara Bhitti Yantra, needs a pit of around 5 feet for astronomy observation, as does the Karka Rasi Vilaya. This information would need to be considered before designing the drainage and requisite slope for the ground level around the Yantra. The present raised external ground level might be one of the main reasons for the repeated rising-damp observed after each spell of rain in the walls of the Misra Yantra. Originally, of course, the projecting plinth would have helped to retard the rise of water from the ground. Over the years this function of the plinth has been rendered useless, since the plinth is now buried beneath the external ground level; and the wall with no buffer, is directly in contact with the ground outside. Effectively, at present the ground level outside is, at the same level or only a few centimeters lower than the internal fl oor level in the Yantra. With reference to the storm-water drains discovered during the excavations, while it has been recorded by Maharaja Jai Singh’s astronomers that drains were constructed to function as water-levels to obtain consistent benchmarks for measurements,16 it is not certain if the drains of the Misra Yantra form part of the original construction. Older records and ASI manuals would need to be checked to ascertain this fact. These observations throw up the question that, if archival records and earlier documentation support the conclusion that the Misra Yantra level was originally lower, would it be advisable to restore the original ground-levels in its proposed conservation, both in terms of historical and functional authenticity as well as its future health and safety? The appropriate answer to this question, appears to be in the affi rmative, in the light of the fact that:

i) the burying of the plinth below the ground is not in consonance with its original appearance;ii) that it seems to have made the Yantra more vulnerable to decay because of repeated water-penetration, as well as having reduced its astronomy functions.

However, it fi rst needs to be ascertained that the restoration of

15 V.N. Sharma, Sawai Jai Singh and his Astronomy, 1995, p.113.

EXCAVATED TRENCH AND PLINTH ALONG DAKSHINOTTARA BHITTI (EAST

EXCAVATED TRENCH AND PLINTH ALONG MIDDLE AND SOUTH SECTIONS

OF EAST SAMRAT GNOMON (EAST

16 See Annexure for a photograph of such drains in Great Samrat, Jaipur Observatory.

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these ground levels does not expose the Yantra to any other problems of water-collection or damp-penetration, keeping in mind the fact that ground-levels and water-tables over the rest of the Observatory site as well as the surrounding levels may have also changed over the years. Recent studies indicate that the ground-water level in the surrounding area has gone down over the past few decades. However, as far as the ground-levels over the Observatory grounds are concerned, these may have been raised to accommodate the grassed lawns around the Yantras. Thus, spot levels will need to be taken of the surrounding grassed lawns to gauge the effect of restoration of the original ground-levels around the periphery of the Yantra. ASI manuals will also have to be perused to look for any documentation recording change in levels. 3. Selective Calibration investigations for the equinoctial sundials of the Misra Yantra (Misra Samrat Dials):

These dials indicate local or sun-time of Delhi. Each dial measures 360 minutes or 6 hours of the day, the western one from 6 a.m. to 12 p.m. and the eastern one from 12 p.m. to 6 p.m. The data collection to check the accuracy of astronomy readings for these dials is complete. It has been observed that there is a discrepancy in the markings of the east and west dials. The Western quadrant of the Misra Samrat has more detailed

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calibrations (in the Hindu system of ghatikas as well as the English system of degrees and minutes) than the Eastern quadrant which is only calibrated in minutes. The Western quadrant is divided into 15 divisions (ghatikas) of 6 degrees each, making a total of 90 degrees. Since 1 degree is equal to 4 minutes, each ghatika or 6 degree division is equal to 24 minutes. Linoleum sheets placed on the Misra Samrat Dials to achieve a surface with sharp edges and an even surface, have been used in the fi eld studies to prepare a preliminary template for time-calibration. Since the present surface of the gnomon parapet of the Misra Samrat is very uneven (having been plastered in patches with cement) it has caused irregularities in the shadow measurements. Thus, observational calibrations made during the fi eld studies, are inaccurate to some degree. Therefore, before preparation of the fi nal template, the gnomon edges will need to be re-plastered, after rectifying the irregularities. The gnomon’s parameters may be checked by taking measurements of the gnomon parapet at every 30 centimetres approximately and checking perpendicularity with plumb lines at these intervals. The proposed sequence for conservation is that the fi nal render on the gnomons would not be after their plastering. Instead, a 3mm linoleum sheet would be fi xed to the re-plastered gnomon surface, based on whose sharp edges, shadow measurements would be taken again to prepare a fi nal template for time-calibrations. The fi nal 3mm lime render layer on the gnomon would then be applied after shadow measurements are worked out. The studies on the shadow movement behaviour of the Misra Yantra with particular reference to the dials of the Misra Samrat have revealed certain other aspects. These are: a) shadow readings before 9 o’clock in the morning and after 4 o’clock in the evening are practically impossible to observe, and therefore measure. This is primarily due to the presence of buildings and trees on the western and eastern periphery of the Observatory Complex. b) The observation calibration template done on linoleum sheets has been seen to be consistent and accurate through different days. However, there is some discrepancy between the observational calibrations and the remains of the earlier calibrations done in the previous restoration work (probably in 1910). This discrepancy amounts to a difference of a minute between the calibrations—the earlier calibration is one minute behind the present calibrations. This may be due to a tilt in the Yantra (perhaps due to settling, or later movements like earthquakes or changes in the masonry of the Yantra). Conclusion: An important conclusion from the intensive fi eld studies on astronomy observations has been that marble is not an appropriate material to take readings, since the material’s veins and texture interfere with shadow readings—the main method of using the Jantar Mantar Yantras. The other conclusion is that there is some difference between the masonry on the western and eastern faces of the Misra Yantra, perhaps because it has tilted over time, or because originally the masonry was not identical on both faces. This needs to be confi rmed through detailed specifi c measurements, and recorded. The Yantra’s overall time-keeping attributes (for the period of the day when observation is possible) are sound and

SHADOW OF GNOMON ON LINOLEUM SHEET PLACED ON EAST MISRA SAMRAT

GNOMON: NOTE IRREGULARITIES IN SHADOW EDGE

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can be conducted with ease. They may be reinstated with the help of a calibration template prepared with the help of the Nehru Planetarium. Normally, theoretical measurements are done for sundials. However, for Jai Singh’s Yantras, it is likely that theoretical measurements would have been supplemented by observational measurements. After the present exercise of observational measurements clarifi es certain masonry parameters of the Yantra, Dr Rathnashree would provide a theoretical measurement template for fi nal application. Since the least count of the Western dial is 6 seconds (which is also in a better state of conservation compared to the Eastern one) while the Eastern dial (which has very few markings visible) has 1 minute as its least count, it seems to imply that the markings on the Western quadrant follow the original system. For purposes of tracing original markings, the Western quadrant therefore is the more authentic one, which may be followed in the re-calibration process. The calibration investigations have also confi rmed an important conclusion with respect to the site development of the Observatory Complex. The 1999 Feasibility Study had recommended the plantation of low height trees at the periphery of the site, and a phased policy of clearing unsuitable plantation (respecting its natural cycle of life and death) over the rest of the site. A detailed list of appropriate planation for the periphery, based on consultation with ecological and landscape experts, and meetings with ASI department offi cials was prepared in July 2003 and sent to the ASI (See Annexure 2 for this list). In the current fi eld studies, it has been seen that many of the trees which impede shadow observations are within the ASI complex. Their management as well as future tree plantation, therefore has to keep in mind how they affect the shadow measurements of the Yantra. The trees within the ASI complex should therefore, ideally not be more than a certain height and their girth also needs to be small. The enclosed list in Annexure 2 may be referred to for such suitable trees.

OVERALL RECOMMENDATIONS, WORK SEQUENCE:

Following from the above studies of the architectural and astronomy related parameters of the Misra Yantra, the sequence of its physical conservation is outlined below. The conservation exercise for the Yantra may be explained as being composed of two broad areas:I CONSERVING THE BASIC STRUCTURE OF THE YANTRA i.e. making it water-tight and weather-proof, removing/rectifying any unwarranted intrusions into the historic fabric, repairing cracks, fi ssures, etc.;II CONSERVING THE FUNCTIONAL COMPONENTS OF THE YANTRA i.e. the various dials and gnomons, restoring their calibrations, curves, repairing and rectifying changes to their surfaces or markings, etc.

1 For instance, the absence of any physical evidence of the original composition of mortar/render on the Yantra, makes it imperative to prepare samples of mortar/ plaster on site. Thus, this would need to be included as an item in the Tender. To ensure the desired level of quality required to restore the Yantra’s astronomy function, the ASI would need to pre-select competent contractors based on their past experience in dealing with such contractors on historical sites.

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The projected procedure for I and II above, may be summarized as follows:1. Experts Masons identifi ed. 2. Detailed specifi cations of Tender for conservation formulated on the basis of the approved Estimate, as well as any amendments caused by the results of the above investigations. 13. A complete set of all relevant documents (Misra Yantra Condition and Measured Survey, Materials Test Report, Astronomy Aspects Report, Sanctioned Estimate, Responses/Amendments/Additions to the Sanctioned Estimate, Detailed Photographic Documentation, Archival photographs) kept at the site offi ce for ready reference, along with log-books. 4. Lime samples of differing compositions of belgiri, etc. prepared on site and checked for weathering, precision of markings, smoothness of surface, sharpness of edges.5. Notices indicating the general process of conservation installed next to the Yantra. 6. Red limewash/snowcem paints carefully removed, fi rst over the internal areas of the Yantra.7. Internal wall surfaces carefully stripped of later cement plaster, to uncover original masonry/ underlying lime plaster.; masonry condition recorded (Condition and Measured Survey of the Misra Yantra (2003) used as base document for updating information.8. Cracks, fi ssures etc. in masonry observed, documented, stitched. 9. An area to the South-East corner of the site set aside for daily preparation of lime for plaster/mortar. 10. Internal walls replastered in approved fi nish/ composition of lime plaster after correcting deviations in plaster11. External walls (without dials) replastered after careful removal of snowcem and cement plaster.12. Base fl oor of Yantra removed of later uneven cement plaster; correct and consistent levels obtained. 13. Internal fl oors relaid in lime at appropriate slopes; external fl oors abutting Yantra relaid after being designed with appropriate levels/drains as close to the original levels as possible (after conducting the remaining spot excavations to ascertain drain conditions and arriving at an appropriate drainage scheme). 14. External fl oor drainage rectifi ed to correct the present situation of water-logging and damp-penetration into the Yantra.15. Gnomon edges carefully stripped of cement plaster.; condition recorded.16. Gnomon edges replastered in lime plaster leaving fi nal render layer.17. Detailed pending measurements of all dials taken.18. Rubbings/ photographic macro documentation of Misra Samrat dials prepared; archival photographs in the records of the ASI, scrutinised for evidence of original appearance and markings.19. Final time-calibration template on Misra Samrat dials prepared. 20. Final render applied on Misra Samrat gnomons and Declination markings inscribed (note: declination markings on the

2 With refernce to the rest of the dials, these may be taken up for conservation in the following order: Meridian dial (Dakshinottara Bhitti); Karka Rasi Valaya; Niyat Chakras; Agra Yantra. While the extent of restoration depends on the state of the instrument, the re-calibration is dependant on the fact that data collection of some of these instruments will take longer. Thus, an astronomer deputed/ appointed specifi cally for this purpose for a fi xed period of time may be necessary.

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gnomons are completely obliterated by cement plaster applied in earlier conservation work).21. Final time-calibration markings inscribed on Misra Samrat Dials after replacement of plaster only where required, for instance where replacement cement plaster has been used or the original has eroded completely.

As far as the sequence and time schedule of the works is concerned, the careful removal of the later cement coat of snowcem over the entire Yantra is estimated to take a period of 3 months, and its cost as approximately 50,000 rupees. After this, individual walls shall be taken up in sequence, their plaster removed and replastered/re-rendered to the extent necessary. The subsequent works such as amount of replastering/re-rendering, and therefore its cost and time taken shall be calculable only after the state of the underlying plaster is revealed.2

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SEQUENTIAL PHOTOGRAPHS OF EXCAVATIONS INVESTIGATIONS 1 MARCH 2007

THE TRIAL TRENCHES EXCAVATED AT THE NORTH-

EAST CORNER OF THE YANTRA (ADJACENT TO THE KARKA RASA VILAYA AND DAKSHINOTTARA BHITTI

YANTRAS)Note the projecting plinth

PHOTOGRAPHIC DOCUMENTATION OF PRELIMINARY MASONRY INVESTIGATIONS OF THE MISRA YANTRA

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TRIAL TRENCHES EXCAVATED AT THE SOUTH WEST CORNER OF MISRA YANTRA (BETWEEN THE WEST SAMRAT GNOMON AND

THE WEST SAMRAT DIAL)

Note the drains running next to the plinth face

SEQUENTIAL PHOTOGRAPHS OF EXCAVATION INVESTIGATIONS 1 MARCH 2007

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EAST SAMRAT GNOMON-

GENERAL VIEW AND DETAIL OF THE ONE METRE

WIDE SAMPLE WALL AREA WITH SNOWCEM REMOVED

(THROUGH APPLICATION OF SANDPAPERING)

Note the cement plaster

SEQUENTIAL PHOTOGRAPHS OF PLASTER INVESTIGATIONS 1 MARCH 2007

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TRIAL TRENCH EXTENDED, NORTH-EAST CORNER OF YANTRA (ADJACENT TO KARKARASI VILAYA AND DAKSHINOTTARABHITTI)

TRENCH, NORTH-WEST CORNER OF YANTRA (AT JUNCTION OF KARKARASI VILAYA AND AGRA YANTRA)

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DETAILED VIEWS: TRENCH, NORTH-EAST CORNER OF YANTRA (ADJACENT TO

KARKARASI VILAYA AND DAKSHINOTTARABHITTI)

TRENCH: WESTERN END OF THE MISRA YANTRA - AROUND AGRA

YANTRA

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TRENCH, SOUTH-WEST CORNER OF YANTRA: WEST SAMRAT

GNOMON


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TRENCH, SOUTH-EAST CORNER OF YANTRA: EAST SAMRAT

GNOMON

Note the plinth only on the eastern face

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TRENCH SE CORNER, MISRA YANTRA (CORNER OF THE EAST

SAMRAT DIAL)

SEQUENTIAL PHOTOGRAPHS OF EXCAVATIONS INVESTIGATIONS 16 MARCH 2007

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TRENCH: UNDER FIRST ARCH ON INNER EAST FACE, MISRA

YANTRA

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TRENCH: AT WEST WALL OF EAST ROOM, GROUND FLOOR, MISRA

YANTRA

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TRENCH: AT WEST WALL, NORTH ARCH, GROUND FLOOR, MISRA

YANTRA

TRENCH: WEST WALL, SOUTH ARCH, GROUND FLOOR, MISRA

YANTRA

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WALL PLASTER REMOVED ON EAST FACE OF CENTRAL WALL,

INNER COURTYARD, MISRA YANTRA

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SEQUENTIAL PHOTOGRAPHS OF EXCAVATION INVESTIGATIONS 11 APRIL 2007

TRENCHES EXTENDED TOWARDS LAWN AT NORTHERN END, NORTH-EAST CORNER OF

THE YANTRA (ADJACENT TO THE KARKA RASA VILAYA

AND DAKSHINOTTARA BHITTI YANTRAS)

Note the drains under the paved ground

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SHADOW OF EAST SAMRAT GNOMON ON WHITE LINOLEUM

SHEET PLACED ON EAST SAMRAT DIAL Note the

irregular edge of the shadow because of irregularities in

gnomon surface

TRENCH ADJACENT TO EAST SAMRAT GNOMON AND EAST

SAMRAT DIAL Note the projecting plinth

face and the drain hole

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TRENCH ADJACENT TO EAST EDGE OF EAST SAMRAT DIAL

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TRENCH ADJACENT TO EAST SAMRAT GNOMON WALL Note the projecting plinth face and the drain on the eastern side and its absence on the northern side

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WALL PLASTER INVESTIGATIONS: REMOVAL OF SNOWCEM UNDER THE CENTRAL ARCH, INNER COURTYARD, MISRA YANTRA

TRENCH, NORTH ARCH ON INNER EASTERN WALL, MISRA YANTRA SHOWING FOUNDATION PROFILE Note the single projection on the wall below the ground level

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WALL PLASTER INVESTIGATIONS ON WEST FACE OF CENTRAL WALL, INNER COURTYARD, MISRA YANTRA

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ANNEXURES

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ANNEXURE 1SYSTEM OF PLINTH AND DRAINS IN GREAT SAMRAT, JAIPUR

From Cosmic Architecture in India, Andreas Volwhasen,

Mapin and Prestel, 2001, pp. 45-6.

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The following is a list of appropriate tree species for plantation in the Jantar Mantar Complex. The selection of the tree characteristics has been done on the basis of the functional, recreational and climatic requirements of the landscape design identifi ed in the Feasability Report (1999), pp. 40–6 and Plate 1.

A summary of the requirements is included below:1. Short trees/ shrubs (about a height of 3.3 M/ 11’) so that the trees even when fully grown do not interfere with the sighting lines for astronomical observations from the Yantras.2. Trees to be planted along the periphery of the site, so that they do not cast shadows on the Yantras even when fully grown. 3. Preferably deciduous trees so that they shade users in summers and allow sunlight on pathways and benches in winters.4. Preferably indigenous to the Delhi region, for more effi cient use of water resources as well as to provide a more authentic ecological context.5. With some element of decorativeness to enhance the recreational aspects of the site.

The following are the species which satisfy a majority of the above requirements. They have been identifi ed on the basis of advice from the landcape and ecological experts, Adit Pal and Pradip Krishen who have specifi c expertise on the area of Delhi.They have been listed in the desirable order of priority.

1. Bistendu (Diospyros cordifolia): can be trimmed to any desired height, native; semi-deciduous. Probably one of the most appropriate trees since, apart from fulfi lling the specifi c site requirements of Jantar Mantar, it is perfectly adapted to Delhi’s climate, drought -ardy and not particluar about its growing medium.

2. Jhinjheri (Bauhinia racemosa): native; not large; deciduous; beautiful in new leaf. Likes full sun, grows on a variety of sandy and gravelly, well drained soils. It would probbaly be desirable to plant this on the west side of the site.

3. Chandni (Tabernaemontana divaricata/ Tabernaemontana coronaria): a shrub that will grow into a small leggy tree, deciduous; with beautiful white fl owers; not native. The coronaria sub-species is essentially a shrub, therefore it would be more suitable to plant the divaricata variety.

4. Kamini (Murraya paniculata): will grow into short bushy tree; not deciduous but can be trimmed to any desired height; not strictly native; bears beautiful scented fl owers twice a year. It will always look visually beautiful.This is reasonably drought hardy, so could be grown on the west

ANNEXURE 2SUITABLE SPECIES FOR TREE-PLANTATION IN THE JANTAR MANTAR OBSERVATORY COMPLEX

(PREPARED AND HANDED OVER TO ASI HORTICULTURE DEPARTMENT IN JULY 2003)

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side of the site. Since it is not deciduous it can also be grown on those areas of the site, where it is not necesary or desirable to have sun in the winters.

5. Kaniaar (Bauhunia purpurea): slightly larger than 11’. sub-himalayan but naturalized in Delhi; semi-deciduous; beautiful pink/ mauve fl owers.

6. Ramdhan Champa (Ochna jabotaoita): large shrub or small tree upto 3 M; deciduous; yellow fl owers; coppery fruits; rare and visually interesting.However, this is is not native, and would be termed an exotic. It may be useful if planted judiciously and not in very great numbers.

7. Erythrina blakei: very small tree (upto 3 M); spectacular red fl owers; probably deciduous. However, inconspicuous otherwise. Therefore, though the size is suitable, in other respects it is probably not an appropriate choice.

Note: The fi nal selection of the tree species and their location on site would need to be done on the basis of the layout indicated in the Feasability Report after Shri N. K. Ahir, Dy. SH, ASI Delhi Circle gives his views on the tree species listed above. Shri Ahir had in a discussion at site also suggested the species Harsingar and Champa, though both can grow larger than the size required for the Observatory Complex.

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ANNEXURE 3PLAN AND ELEVATION SHOWING LOCATION OF TRENCH EXCAVATIONS

EXCAVATIONS, PLASTER AND CALIBRATION INVESTIGATIONS, MISRA YANTRA, JANTAR MANTAR, NEW DELHI

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