﻿EQUIPMENT AND WORK OF AN AERO-PHYSICAL OBSERVATORY. O 



Thermometry and Hygrometry. 



Standard types of thermometers — exposed, wet-bulb, maximum and 



minimum, water and soil. 

 Thermographs and self-registering psychrometers. 

 Assmann aspiration psychrometer. 

 Telethermographs and telehygrographs. 



Insolation. 



Actinometer (Schwolsen). 



Langley's bolometer, with appropriate galvanometers for the explor- 

 ation and mapping of the solar spectrum, particularly the infra- 

 red portion. 



Photographic records of the more prominent absorption lines due 

 to aqueous vapor in the atmosphere, and comparison, after proper 

 scale determination, with the intensity of standard solar lines, with 

 the ultimate aim of ascertaining this distribution of vapor in the 

 atmosphere at various altitudes and variations therefrom. 



Spectroheliograph. A good 12 or 14 inch photographic objective for 

 investigating the relations of solar spots, faculse and prominences. 



Nephoscopy and Pluviometry. 



Sunshine recorders of various types. 

 Nephoscopes and Pole star recorders. 

 Rain gauges and evaporometers. 



Atmidometry. 



Barus's device for showing colors of cloudy condensation. 

 Aitken's dust-counter or coniscope. 



The determination of the amount of haze or smoke present in the 

 atmosphere is now quite neglected in meteorology^ although 

 a matter of very considerable importance to health. We 

 should have daily records of the relative purity of the atmos- 

 phere. 



Anemomp:try. 



Anemoscopes. 



Anemo-cinemograph — an instrument showing the varying force ex- 

 erted by the wind, superior to the old form of anemograph ; and 

 yet some further improvement looking to a fuller recognition of 

 what has been termed " the internal work of the wind " is desirable. 



Helicoid anemometer. 



Clino-anemometer, or instrument for registering currents not hori- 

 zontal. 



Wind pressure gauge and suction anemometer. 



