INTRODUCTION. 7 



sun and wind. It contains a Dry and a Wet Bulb and Maximum and Minimum 

 Thermometers. The former are read generally seven times a day and the Maximum 

 and Minimum are read and set at 22 h (10 p.m.). The bulbs of the Dry and Wet are 

 four feet above ground. The Black Bulb in vacuo is mounted four feet above ground 

 on a post near this screen, and the Radiation Minimum is exposed on a black painted 

 board level with the ground a few yards away. In the printed tables the highest and 

 lowest values for each month of the. Maximum and Minimum in the screen, and of 

 the Black Bulb and Radiation Minimum outside, are indicated by bold-faced type. 

 The columns to the right contain the Amount of Cloud as observed five times a day. 

 At the foot of each column is given the mean value for the month. 



Rainfall. — The hourly record of the rainfall at Fort- William Observatory is 

 obtained from a self-recording Beckley raingauge with circular rim 100 square inches 

 in area. It stands on a grass plot in front of the Observatory and the rim is 20 inches 

 above ground. The arrangement of the printed tables is the same as that of the Ben 

 Nevis Observatory Rainfall : all snow, hail, etc., is melted and measured as rain, the 

 fall being apportioned as nearly as may be to the hours during which it was observed 

 to fall. In the months of March and April 1891 the gauge was under repair and 

 hourly records were not obtained, the daily totals given on the sheets being the 

 amount collected in an 8 -inch gauge standing with rim 20 inches above ground close 

 to the Beckley gauge. This gauge was read daily at 22 h (10 p.m.). From the 3rd 

 to the 15th of January 1892 inclusive the precipitation was wholly snow, and no 

 attempt was made to distribute the fall over the hours of the day. The daily totals 

 only are given. 



The Sunshine is recorded at Fort- William Observatory by a Campbell- Stokes 

 Sunshine Recorder mounted on a stone pillar in the Observatory grounds. The printed 

 tables are similar to those for the Ben Nevis Sunshine ; but owing to the hills which 

 surround Fort- William, the possible sunshine at all seasons is less than on Ben Nevis, 

 and the values entered in the " Total Possible " column have been computed from notes 

 made of the times of Sunrise and Sunset as actually observed when opportunity offered, 

 and these values have been used in computing the "Percentage of Possible" in the 

 Monthly and Annual Mean Values. If it is desired to compare the Fort- William 

 Sunshine with the possible for a clear horizon, the " Possible " values entered in the 

 Ben Nevis tables for the corresponding months may be used. 



The Public School, Fort- William. 



The observations recorded at this Station, which was under the charge of Mr. Colin 

 Livingston, extend from 1st January 1888 to 31st December 1890, and consist of 

 " Eye " readings taken five times a day. The barometer in use was of Board of Trade 



