May. 1902.] 



KNOWLEDGE, 



103 



would indicate a blameworthy iudift'erence to tie duties 

 of religion and to the requirenieuts of society. 



But ;i serious difficulty has been growing for many 

 years. Two hundred years ago Kajah Jey Singh noted 

 that the calculation of the places of the stars as obtained 

 from the tables in common use, gave widely different 

 results from those obtained liv observation ; the times 

 and magnitudes of the eclijises of the sun and moon, the 

 tunes of the risings and settings of the planets, and of the 

 ai)]>earance of the new moon, were all faulty ; the ancient 

 Siddhantas having been left without revision from the 

 time of Bhaskara, the author of the Siddhanta-Siromani, 

 nearly six hundred years before. It was in consequence 

 of this discrepancy, keenly felt even then, that Kajah Jey 

 Singh obtained the permission of Mahommed Shah to 

 erect observatories in order to obtain new data by which 

 th(! tables should 1)6 corrected. Three of the live obser- 

 vatories erected by Jey Singh are well known, those of 

 Jeypt)re. Delhi, and Benares. Of these, the one at Delhi, 

 established about the year 1710, appears to have been 

 the first. 



The tientur Muntur, or Royal Observatory of Delhi, 

 though barely two centiu-ies idd, is of a thoroughly 

 ancient type in its conception, and was intended for naked 

 eye work alone. Just as at the Koyal Observatory at 

 Greenwich the transit circle and altazimuth are considered 

 the two fundamental instruments, so here at Delhi the 

 chief structures were evidently designed for corresponding 

 pur])oses. 



The first object to catch the eye is the great gnomon, 

 the vertical section of which is a right-angled triangle, 

 with an hypotenuse of 118 feet, a base of 104 feet, and a 

 perpendicular height of hi approximately. The face of 

 the gnomon therefore is parallel to the axis of the earth, 

 its angle corresponding to the latitude of Delhi. Up the 

 middle of the gnomon runs a staircase, and right and left 

 of the gnomon are great sectors on which its shadow falls; 

 these also being i)rovided with steps over which the 

 sliadow^ took four minutes of time, corresponding to one 

 degree of arc, to pass. A smaller structure near has some 

 variations in its design, the gnomon being in the centre 

 and flanked on either side by semicircles sloping down- 

 wards from it towards the horizon. Further to the south 

 of these gnomons, the chief use of which must simply have 

 been to give the solar time, are two large buildings, 

 which are evidently intended to serve as altazimuths. 

 The two buildings are exactly alike in design and size, and 

 they give the appearance from outside of being miniatures 

 of the Colosseum at Rome. Withiu they are seen to be 

 perfectly circular enclosures. The wall of each is pierced 

 by three tiers of windows, thirty in each tier, the breadth 

 of each window opening being precisely equal to the width 

 "f the wall between each pair of windows. The difference 

 between the two buildings is simpl}' a question of position, 

 the two being so arranged that the windows of one 

 command precisely those azimuths which are hidden by 

 the wall of the other. In the centre of each enclosure is 

 a pillar rising to the height of the enclosing wall, whilst 

 from the circular wall thitty stone sectors are directed 

 towards the central pillar, but do not quite reach it. The 

 building is 17"2\ feet in circumference, or 55 feet in 

 diameter, and the sectors riinuiiig from the wall towards 

 the pillar are 21^ feet in length. The wiu'lows, no doubt, 

 were intended to enable the altitude and azimuth of any 

 celestial object to be read off at sight, and for nuigli 

 )iositions no doubt it did fairly well. Still Jey Singh does 

 not seem to have effected any reformation of the Indian 

 Calendar, and his observatories, despite their great size, 

 cannot have been of inm-h value for reallv scientific 

 wiirk. 



The interest of Jey Singh's observatories lies for us in 

 the fact that they recall a time far in the past when 

 astronomers sought for exactness by the erection of huge 

 structures of stone. Of these the Great Pyramid is by far 

 the greatest and most perfect exam|)le. The north shaft, 

 pointing to Alpha Draconis, the pole star of the period, the 

 grand gallery which may very well, as Proctor suggests, 

 have been used as a vast transit chamber, give evidence of 



■Jill' Giiiiur Aiuiiiu]-. ..!• i;o\al ul.M-rratory of Delhi. 



its astronomical purpose, whilst the care with which the 

 exterior of the Pyramid has been oriented, would fix most 

 delicately the dates of recurrence of the spring and 

 autumnal equinoxes. This would be seeu from the circum- 

 stance that on one day in spring the north face of the 

 Pyramid would be in shadow at sunrise, and the next day 

 the south face, whilst the reverse effect would be noted in 

 the autumn. The exact days of the eqiunoxes would not 

 indeed be thus pointed out, but the return of the year to 

 the same point would be marked with great prevision. 



Britain has its own monument — Stoneheuge— which has 

 been claimed as, if not indeed an astronomical observatory, 

 at least an astronomical temple, and many attempts have 

 been made to determine the date at which it was erected. 

 The difficulty, not to say the imjjossibility, of solving this 

 problem in the present state of the monument may be 

 inferred from the fact that the dates which different 

 careful observers have deduced for its erection extend over 

 a j)eriod of more than 2000 years. 



The real work of astronomy, even in the pre-telescopic 

 age, was never done in edifices like these. Nor, indeed, does 

 it require much knowledge of human nature, essentially 

 the same 5000 years ago as to-day, to see that the true 

 secret of the Pyramid, the amply suflBcieut cause for its 

 Iniildiug. was the vanity of the ruling Pharaoh. We get 

 a graphic hint of this in the narrative in Genesis of the 

 founding of a yet earlier observatory, for so no doubt it 

 was. "They said, go to, let us build us a city and a tower, 

 whose top may reach unto heaven, and let us make us a 

 name." Alike' at Delhi, at Ghizeh, and on Salisbury 

 Plain, as by the Euphrates, to "make a name" was, 

 beyond doubt, the exciting motive. Astronomers may 

 have been employed to superuitend the work, astronomy, 

 or the cult of the celestial bodies, may have been the 

 excuse. Init the real oliject was advertisement. 



But the work which the pretentious buildings of the 

 Rajah of Amber failed to accomplish has been done quite 

 recently bv very humble means, and by a recluse in an 

 obscure village 'in the hills of Orissa.* Chandrasekhara 

 Simha Samanta is a near relative of the Raja of 



• S,e Knowlkdoe, \'()1. X.'CII., p. :;o7. Siddliiinta-Darpana. 



