396 Proceedings of the Royal Physical Society. 
XXV. Results of Meteorological Observations taken at Edin- 
burgh during 1893. By R. C. Mossman, a F.R.S.E., 
F.R.Met.Soc. [Plate X.] 
(Read 21st February 1894.) 
During the past year no change has been made in the 
methods of observation or in the equipment of the station. 
A “Fortin” standard barometer has been added to the stock 
of instruments, but the values given in the tables have been 
obtained from readings of the Kew marine barometer described 
in last year’s report. New averages for the last 130 years 
are in process of computation, but beyond the means for 
temperature none are as yet completed. In order to show 
the more intimate relation existing between the various 
elements of climate, weekly averages of pressure, tempera- 
ture, rain, and sunshine have been calculated, the number of 
days on which east and. west winds respectively prevailed 
being also given, north winds being referred to the former, 
and south winds to the latter direction. A table of 
weekly mean temperature variability has also been added. 
These values are obtained by taking the mean temperature 
(= + min, 
2 
example, the mean temperature of December 15th was 46°4, 
and for the day following 51°°6; the variability was thus 5°:2, 
It may be remarked that this variability is quite distinct 
from daily range, which is greatest in spring and summer, 
whereas the greatest changes in the mean temperature of 
successive days take place in winter, when the absolute 
quantity of aqueous vapour is at a minimum. 
The thickness of the rainband in the spectrum of sunlight 
= mean temp. ) difference from day to day. For 
1 The following are the instruments in use :— 
Pressure.—Standard ‘‘ Fortin’? barometer, Kew marine do., mercurial 
barograph, Richard barograph. 
Temperature.—Max. and min. thermometers, black butb solar radiation 
thermometer, bright bulb terrestrial radiation thermometer, Richard 
_ thermograph. 
Humidity.—Mason’s hygrometer, Richard hygrograph. 
Miscellaneous. —Robinson anemometer, wind vane, sunshine recorder, rain 
gauge, storm rain gauge, rainband spectroscope, koniscope and stephanome,. 
