1844.] On Rain Guages and Registry of River Freshes. 183 



In the small cistern or well, each large division is 4 inches 

 in length, but denotes only one inch of rain. The smaller 

 divisions, each $ of an inch, shew tenths of an inch of rain, 

 and every one of the smallest divisions, ^ of an inch, shews 

 two hundredths of an inch of rain. The small cistern will 

 hold six inches of rain, which is the greatest quantity that is 

 ever likely to fall in 24 hours ; but lest there should be any 

 neglect, the upper part of the cistern is also marked and the 

 whole will shew 1 8 inches of rain. The cistern ought never 

 to be covered. If dirt collect in it, it must be swept and 

 washed out. The water must be let off and the orifice closed 

 ae soon as the depth is entered in the register, which it will be 

 convenient to have made in the accompanying form, 



Form.* 



Rain Guage at 184 



Mouths. 



1 



1 Date. II 



In English fi. 



*ures. 



In Nat 



ive cha 



racters. 



Name of the 

 Observer. 



Inches 



tenths. 



parts. 



j inches. 



tenths. 



parts. 





















Total ©f the 

 Month. 



















! Daily ave- 

 ! rage. 



















* Any vessel that is of the same size from top to bottom will do for a rain 

 guage. The depth may be accurately measured at once, or if the number 

 of square inches in the top surface be ascertained, then if the number of cubic 

 inches of rain that falls in it be divided by these square inches, the quotient 

 will be the depth of rain fallen in inches. 



The number of cubic inches may be found by weighing the water, allowing 

 253^ grains for each cubic inch. A fluid ounce is 1 Cubic inch and k9\ hun- 

 dredths, very nearly 1 Cubic inch and nine tenths. 



* Blank Registers of this form printed on writing paper arc procurable 

 at the Christian Knowledge Society Press, price 9 as per annual sheet- 



