2 Proceedings of the Royal Physical Society. 



detailed weekly and monthly reports — 140 in number — 

 continue to be sent to the Scottish Meteorological Society, 

 the Eegistrar-General for Scotland, and the Meteorological 

 Office. The long averages with which the mean monthly 

 values are compared will be found in Part II. of my paper 

 on " The Meteorology of Edinburgh." ^ As it is some years 

 since any account of the instruments has been given, the 

 following particulars may be of interest. 



Position of Station. — The observing station is situated in 

 the Newington district of Edinburgh, the general height 

 of the ground being 250 feet above mean sea-level. The 

 position is open, and the air circulation remarkably true, the 

 only disturbing factor being exerted by the high ground 

 of Arthur's Seat (822 feet), about one mile to the east. 

 During the thirty years preceding the establishment of this 

 station in 1886, the observations were made within a mile 

 of the present site, and for many years within 200 yards. 



Barometers. — The standard barometer is on the Fortin 

 principle, and has a tube six-tenths of an inch in diameter. 

 It has a Kew certificate. A spare Board of Trade barometer 

 is used as a check. There are two barographs, one an 

 elaborate mercurial instrument by Eedier of Paris, the other 

 being one of the well-known Eichard aneroidographs. The 

 paper to receive the registrations is coiled around revolving 

 cylinders driven by clockwork. The sheets are changed 

 every week. There is also a long range Watkin aneroid, 

 which has been found remarkably correct. 



Thermometers and Hygrometers. — The maximum and 

 minimum thermometers are exposed along with the dry 

 and wet bulb thermometers in a Stevenson's thermometer 

 screen placed over a grass plot. Another but larger screen 

 cojitains a Eichard thermograph and a hygrograph by the 

 same makers. These instruments give traces of thermometric 

 and hygrometric fluctuations respectively. A black bulb 

 maximum solar radiation thermometer is freely exposed 

 at a height of 4 feet above the ground, and a terrestrial 

 minimum is placed on the surface of the ground. Earth 

 thermometers, with their bulbs buried in ordinary garden 



^ Trans. Hoy. Soc. Edin., vol. xxxix. pp. 63-207. 



