18370 



Account of the Trevandrum Observatory, 



59 



lions by reflection from quicksilver in the manner now practised at 

 Greenwich. These two instruments are ordered respectively from Mr. 

 William Simms, and Mr. Thomas Jones, with the same instructions as 

 to perfection as those given to Mr. Dollond for the transit instrument, 



5th. A clock, exactly similar to the transit clock, to be placed in a 

 corresponding recess on the opposite side of the same pillar. 



6th. An altitude and azimuth instrument, having 18 inch, and 15 

 inch circles, with three micrometrical microscopes to each, made by 

 Mr. Simms, to be placed on the top of the granite pillar above the 

 middle room, and under the revolving dome No. 1. This instrument 

 having been ordered by me, for my own use, about two years ago, has 

 just arrived at Madras, and is now on its way to me by land. 



7th and 8th. Two powerful telescopes, one of the refracting and 

 the other of the reflecting kind, with micrometers and all appur- 

 tenances for observations on the double stars, &c. to be placed under 

 the revolving domes Nos. 2 and 3. 



Besides these principal instruments, the Observatory will be com- 

 pletely furnished with meteorological, magnetic, and pendulum, instru- 

 ments and apparatus; and the assistance afforded by His Highness in 

 the observing and computing departments, is as complete and liberal 

 as every other part of the establishment. 



I may here mention that until these instruments are received from 

 England, observations will be carried on with small but very excellent 

 ones of my own — consisting of the altitude and azimuth circle above 

 mentioned—a thirty inches transit instrument — an equatorial, by 

 Troughton and Simms— a forty-six inches refracting telescope — chrono- 

 meters — reflecting circle, &c. &c. 



I also take this opportunity of announcing that a system of hourly 

 observations throughout the day and night, of the thermometer, baro- 

 meter, and hygrometer, has already been commenced at this observa- 

 tory, the result of which will be duly made public : and this, as supply- 

 ing an important desideratum in the science of meteorology, will 

 doubtless be received by all cultivators of that branch of physics, with 

 the consideration and gratitude which the present Rajah of Travan- 

 core will by it eminently entitle himself to. 



3. — The Locality. 

 The Trevandrum Observatory stands on an insulated hill, about sixty 

 feet high, and 1951 feet above the level of the sea (as ascertained by 

 levelling), from which it is distant, in a straight line, about two miles. 

 It commands an extensive and beautiful view of an undulating and 

 finely variegated country towards the north, the east, and the south — 

 and (overlooking the declivity towards the sea and its fringe of cocoa- 



