OF METEOROLOGICAL INSTRUMENTS. 



23 



FIG. 64. 



FIG. 73. 



64. Rain Gauge^ of stout copper, height twelve inches, receiving surface ten 



inches square, and funnel formed inside to prevent evaporation, with jar 

 graduated to hundredths of an inch, and small receiver to prevent the neces- 

 sity of lifting the gauge when measuring the rain (fig. 64) . 2 10 



65. RAIN GAUGE (CASELLA'S), pedestal form, 3 feet high, receiving surface 8 inches in 



diameter, made of stout copper japanned, with strong glass tube graduated to 

 show 3 inches of rain in tenths and hundredths, with extra stop-cock for frosty 

 weather. In this arrangement the rain is measured as it falls, being visible at 

 all times in the glass tube, and is poured off by simply turning the stop-cock, 

 without removing the gauge from its place (Jig. 65) p. 22 . 3 10 



66. Rain GailgC; cylindrical form, of stout copper, 8-inch, diameter, with deep brass 



rim, and inside receiving-can or bottle, by which large or small quantities are 

 measured without disturbing the gauge, and efficient protection secured 

 against evaporation or frost or of overflow during the heaviest rains of the 

 tropics . . . . . . . 3 15 



67. RAIN GAUGE (CASELLA'S TEOPICAL), to measure up to 40 inches of rain, in lOOths 



of inches, in japanned tin, with brass rim . . . 1 10 



68. Rain Gauge (SYMON'S), 5-inch, diameter, 

 etc. (fig. 68) p. 22 . 



tin, with receiving-bottle 

 15 6 



69. RAIN GAUGE (SYMON'S), of copper, for durability . . 110 



Instructions for Use. The funnels of this rain gauge and the five preceding ones are 

 made to lift on and off the cylinder, and a can or bottle for receiving the rain from the funnel 

 is placed inside. When rain is to be measured, remove the funnel, take out the can, and 

 pour the rain collected into the glass measure, which is graduated to represent hundredths 

 of an inch, up to 0.50, or half an inch. Place the glass upon a table or other horizontal 

 surface for support and steadiness, bring the eye on a level with the surface of the water 

 and read off. Should more than half an inch of rain have been collected, successive measure- 

 ments will be necessary. For instance, having measured half an inch, or 0.50, empty the 

 glass, fill up again from the collecting-can, and add the result of this second measurement, 

 to the half -inch measured previously. For example, should the second reading be 0.07, the 

 two readings added together will give the total rainfall or 0.57 of an inch. 



