1883.] Thermometric and Hygroinetric Observations. 313 



screen with similar thermometers to those at 4 feet. From this point 

 upwards the tower is quite open, besides which there is free circulation 

 •of the air through the large open windows on the four sides of the 

 tower. 



(3.) In a box with three of its sides louvre boarded, and of which 

 the height, breadth, and depth are respectively 1 foot 5 inches, 

 8-§- inches, and h\ inches, the Siemens electrical thermometer and also 

 a standard thermometer for occasional check readings. The box or 

 " wall screen " faces west-south- west, is attached to one of the 

 northern pinnacles of the tower, and is 260 feet above the ground. 

 When first put up a board was fastened on the south side of the 

 screen to protect it from the sun's rays ; as this, however, hardly 

 afforded sufficient protection, an outer screen was placed over the wall 

 screen in September. The cable has been brought down the 

 inside of the tower, then through the belfry, and so to the base of the 

 tower inside the church, where the galvanometer is fixed. 



The accompanying figure shows the relative situations of the three 

 sets of thermometers. 



A = Siemens 1 Thermometer. 



B = Stevenson's Screen on Belfry. 



C = Stevenson's Screen in Church yard. 



All the thermometers are read every morning at 9 o'clock ; and 

 simultaneous readings of the electrical thermometer at the summit of 

 •the tower and of the dry bulb thermometer in the churchyard, 

 together with the direction and force of the wind, the amount of cloud, 

 -weather, &c, are also made regularly at 11 a.m., 1, 3, 5, 7, and 9 p.m. 



