Ixxnl 
of 13 years, from 1739 to 1751 inclusive, the rainfall in many 
parts of England was much below the annual average ; and there- 
fore, water-works with supplies based on averages for shorter 
periods and in more recent times, might, at some future period, 
prove seriously insufficient.—Dr. Barham next remarked that, 
generally, the total rainfall throughout the year was too much 
relied on, without due consideration of the monthly fall. It was 
especially important to ascertain the amount of rainfall at the 
period of the year when vegetation was mainly affected by it. On 
this subject, diagrams were exhibited showing the results of ob- 
servations at Bodmin, Altarnun, Truro, Penzance, and Helston ; 
and it was remarked that at Alternun, 500 feet above the sea-level, 
the amount of rainfall for the year was 59, as against 40 at Truro; 
but at Altarnun the great bulk of the fall was in the winter. 
months ; the summer rainfall being often less at Altarnun than in 
the lower districts mentioned ; and this smaller rainfall in summer 
on the higher station was combined with a considerably higher 
temperature than that of the western localities. One result of 
this was that the cultivation of cereal crops was very successful in 
that district, notwithstanding that its total rainfall in the year was 
much in excess of the other districts. On the summit of Dart- 
moor again, the summer rainfall was but little more than at Ply- 
mouth ; its excess was in the winter, when it was, comparatively, 
of little consequence except as a storage supply for the future. In 
regard to vegetation, it was of very little consequence whether the 
rainfall was twenty or thirty inches in the winter months, if during 
the summer there was a fair degree of heat and but little rain. It 
was also to be observed that the humidity of any district was not 
to be measured by the amount of rainfall; the diagrams showed, 
for example, that at Truro, although in April last the amount of 
rainfall was less than two-tenths of an inch, that month was really 
one of considerable moisture; whilst in May, when the rainfall 
was nine times as great, the humidity of the month was actually 
diminished.—The amount of dryness in the air was of great im- 
portance, not only with regard to vegetation, but also as affecting » 
the physical and mental qualities of human beings; thus the 
changes effected in the constitutions and the physique of Anglo- 
Saxons resident in America, were greatly due to the dryness of 
the climate, especially in the States bordering the Atlantic. 
With reference to the importance of securing records of highest 
temperature, Dr. Barham stated that there were already sufficient 
data for showing the general maxima of temperature in different 
parts of the county ; and it was worthy of remark that not only 
was the maximum less in Scilly than at Penzance, Helston, and 
Truro; but even between two places so near to each other as 
