328 Description of an improved Rain Gage. 



ter in the gage, it wou'd, evidently, form a stratum on 

 the bottom of one inch in height; and if we conceive 

 this stratum to be divided, by horizontal sections, into 100 

 eqja parts, these parts would form strata, each of which 

 would be the j^o^h of an inch in height; and, being equal 

 to a cubic inch, would weigh 222.525 grains. Let us fur- 

 ther suppose that one of these strata is subdivided into 

 10 equal parts by sections in the same direction, each of 

 these parts would, evidently, form a stratum of water, 

 whose height would be only the joVot^ P^rt of an inch ; and 

 being eqaal to the 10th part of a cubic inch, would weigh 

 25.2525 grains. 



Having then, the weight of 100 cubic inches correspond- 

 ing to one inch in altitude ; the weight of one cubic inch 

 to the T^o^^^ti of an inch; and the yV^h of a cubic inch to the 

 j-^'^^th part of an inch ; it is easy to see that the height of 

 the water in the gage may be obtained by making one, or 

 other, of the above numbers a divisor to the corrected 

 weight of the water, in troy grains. But this trouble is 

 rendered unnecessary by the use of the following ta- 

 bles : — 



Table 1. 



One pound troy 

 One ounce, 

 One drachm. 

 One scruple, 



Troy Weight. 



Grains. 

 = 5760 

 480 

 60 



= 20 



Table 2. For Redticing A- 

 voirdupois Weisht. 



Troy Grains. 



One pound avoirdu- 



pois, = 



Half pound, = 



I of a pound, = 



Two ounces, = 



One ounce, = 



Halfounce, = 



Quarter ounce, = 



7000 



3500 



1750 

 875 

 437.5 

 218.75 

 109.375 



