Easy Method Of Making A Rain Gauge
A very simple rain gauge, and one which will answer all practical
purposes, consists of a copper funnel the area of whose opening is
exactly ten square inches: this funnel is fixed in a bottle, and the
quantity of rain caught is ascertained by multiplying the weight in
ounces by 173, which gives the depth in inches and parts of an inch.
In fixing these gauges, care must be taken that the rain may have free
access to them: hence the tops of buildings are usually the best
places. When the quantities of rain collected in them at different
places are compared, the instruments ought to be fixed at the same
heights above the ground at both places, because at different heights
the quantities are always different, even at the same place.