Nine Inch Conical Rain Gage. 323 
A rain gage of this kind may be made of tin ware, painted and 
varnished, for less than half a dollar; and if observations made with 
it be repeated before the water rises high in it, they will be as accu- 
rate as those which are made with the rain gages commonly used, and 
costing twenty times as much. 
The dimensions of the base of the cone may be taken at pleasure ¢ : 
five or six inches for its diameter may be considered advisable ; but 
it is essential to the accuracy of the instrument that its height, meas- 
ured perpendicularly from its inside apex to its base be exactly nine 
inches. : , 
The conical rain gage, of which I gave a description to the Insti- 
tute* sometime since, admits indefinitely of a scale of large divis- 
ions ; but the cost of its construction is considerable. The scale of 
the one I have now described is limited in its graduation; but it is 
such as will serve, in a satisfactory manner and with as much ac- 
curacy as can be expected, the purpose of ascertaining the quantity 
of rain that may fall in the course of a year; and I hope that its 
cheapness, and easy acquisition, will induce many to possess them- 
selves of it, and by its means, contribute to the observations institu- 
ted in our State on this important branch of Meteorology. 
To persons whose minds have a turn to rational pursuits, observa- 
tions of this kind would afford much gratification, even should curiosi- 
ty alone be the prompter, but it would be heightened by the conscious- 
ness that thereby they might coéperate with others, intent on the pro- 
motion of useful science ; besides, as a mere matter of amusement, 
this may be ranked among the rational and refined, which gentlemen 
of leisure might cultivate much to their pleasurable enjoyments, and, 
I may add, to their reputation as useful members of society. 
To facilitate the making of a rain gage of this kind, I furnished a 
tinman with a pattern, which was a sector of 96° 22’ of a circle of 
9.34 inches radius. ‘The chord of this sector is 13.92 inches. This 
pattern, made of paper, having its side edges brought together, would 
form a cone exactly nine inches high, with a base of five inches diam- 
eter. In cutting out his sheet-tin by this pattern, he was directed to 
add just so much to the sides as was necessary for lapping, in soldering 
them to each other, and to add so much to the archas was necessary 
for doubling, in order to stiffen the rim. By these directions he was 
enabled to make the cone as required, with accuracy, and ata trifling 
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* Vol. I. No. 6. p. 60 of the Transactions. 
