238 
Phillips in the volume of Transactions of the Association for 
the year 1835. Three gauges were used in these observa- 
tions : the first was placed on a large grass-plot in the 
grounds of the Yorkshire Museum; the second on the roof 
of the Museum, at an elevation of 43 feet 8 inches ; and the 
third on a pole 9 feet above the level of the battlements of 
the great tower of the Minster, at an elevation above the 
ground gauge of 212 feet 10^ inches. The total quantities 
of rain received by these gauges during the three years of 
observation were as follows : — 
1st gauge 65‘430 inches. 
2nd „ 52-169 „ 
3rd „ 38-972 „ 
From these numbers it appears that the ratio of increase of 
size of a rain-drop is 0-679 for the last 213 feet of its fall, and 
0-254 for the last 44 feet. 
A very able discussion of the whole series of observations, 
with reference to the temperature of the seasons, led Professor 
Phillips to the following formula for calculating the difference 
between the ratios of the quantites of rain received on the 
ground, and at any height A, the value of the co-efficient p 
depending upon the temperature t' of the season : — 
d=ph~ 
Calculated by means of this formula, the mean height of 
the point at which rain begins to be formed, is 1747 feet; 
and the height at which the quantity of rain is only one-half 
of that which falls on the ground, is 356 feet. 
Assuming the mean temperature of newly fallen rain at 
York to be 48°; and taking the latent heat of vapour at 1210° 
at the temperature of 32° Fahrenheit — the value adopted by 
Professor Espy in his Meteorological Reports and Essays, — 
it will be found that a rain-drop cannot acquire the increase of 
size indicated by the observations, by the condensation of 
