The Astronomical Observatories of Jai Singh c4.s2.13

c4.s2.13

¹ The Paris observatory is 0° 9' 20.9 secs = 2° 20' 13.5" E. of Greenwich. Jaipur observatory is 75° 49' 18.5" E. of Greenwich, while Delhi observatory is 77° 13' 5" E. The approximately correct latitudes are Delhi 28° 37' 35" N., Jaipur 26° 55' 27" N. In the latter part of the seventeenth century the difficulty of chromatic aberration was partially overcome by the use of very long telescopes—often a hundred feet or more. This led to 'aerial telescopes' without tubes of which la Hire in 1715 gave a description possibly Father Boudier's was a small one of this type.