1883.] H. Warth — Air-temperature Sf humidity at dijferent elevations, 81 



pattern, thatched with straw. It differs herein from' the shed in the Tri- 

 gonometrical Survey Office. The Trigonometrical Survey Office shed has not 

 only more trees round it, but is also enclosed by lattice work. Hence the 

 means of the daily dry minima were at the Trigonometrical Survey 5&° 

 higher during the time from 1st of October to the 31st of December, 1882. 

 Further the means of the daily dry maxima at the Trigonometrical Survey 

 were 2 6° lower during the same period. 



As will be seen from the records, the memo, which was written by Mr. 

 Blanford on the 8th of October, 1879, is taken for guidance. 



2. The elevated observatory called No. 2 is located on the top of a 

 light but strong scaffolding, constructed of bamboo and iron, with ladders 

 of bamboo used for access. Its height is 70 feet. The observatory is 

 sheltered by a threefold roof of iron, wood and cloth, in separate layers 

 with airspace between. There is also a very little lattice work on the east 

 side and on the west side. The whole is so designed that there is the 

 greatest possible access of air and only so much shelter that the sun cannot 

 heat nor directly shine upon the thermometer cage. The vertical angle of 

 the sun at noon varies from 36° in winter to 83° in summer. The rays of 

 the rising and the rays of the setting sun make on the 21st of June a 

 horizontal angle of about 12'7*'. These angles were considered in the 

 design of the roof and the lattice work. 



The strength of the scaffolding is supposed to be sufficient in case of 

 a storm of 60 miles an hour, but not beyond. 



3. Before the roof was fixed on the scaffolding, it was set up alongside 

 observatory No. 1 and provided with the cage and thermometers. Com- 

 parative observations were then made during 5 days between No. 1 and the 

 temporary roof containing the thermometers of No 2. From 22nd to 26th 

 September, 1882, these comparative observations were continued with the 

 following mean result. 



Minimum dry,... 

 Maximum dry, 

 10 A. M. dry, ... 

 10 A. M. wet., ... 



4 p. M. dry, ... 



4 p. M. wet, ... 

 Daily mean dry, 



No. 1 observatory, 

 thatched standard 

 pattern shed. 



Roof of No. 2 obser- 

 vatory, temporarily 

 set up on the grass 

 plot. 



690 

 89-2 

 84-5 

 741 

 856 

 74-4 

 773 



