POPULAR SCIENCE REVIEW. 
72 
the subject it deals with, and by no means because we attach any value 
to the author’s hypothesis, or to his skill in laying down his views. Such 
works as the one before us, being in reality the expression of foregone con- 
clusions, are only calculated to trammel the cause of biological philosophy, 
and to impede scientific progress — upon the very principle which Dr. Morris 
argues for — by infecting healthy minds with the germs of obscure reasoning, 
imperfect grasp of subject, and shallow observation. 
EAIN.* 
TT7H0, if not Mr. Symons, is able to speak authoritatively on the various 
’ ’ meteorological phenomena of rain and rain-fall ? To him we owe 
nearly all that has been done in collecting rain statistics during the last few 
years, and to him we are indebted for the handy and clearly written little 
volume which has just been issued. As the title of the book indicates, Mr. 
Symons treats of the employment of rain-gauges. First he tells us how 
rain is collected. In this part of his work he describes the different forms 
of gauges now in use, and illustrates his descriptions by woodcuts of seven 
or eight varieties of the instrument. He dwells at some length on the sub- 
ject of the receiving surface of a rain-gauge — should it be large or small? 
This is a qucestio vexata among meteorologists, and it has been a bone of 
much contention between the author and the Mechanics'* Magazine, the 
former asserting that small rain-gauges are at least as good as large ones, 
and the latter advocating the opposite opinion. Mr. Symons gives the 
results obtained from the observations on the series of experimental gauges 
at Caine, and from these it certainly seems that the balance of evidence is 
in his favour, but really the difference is so extremely trifling, that it appears 
to us as if the combatants in the discussion were fighting for a shadow. 
The author gives some good practical advice on a point in which amateur 
meteorologists are much engaged, viz. setting a gauge to work,” which 
may thus be summarised. The mouth of the gauge should be made perfectly 
level, and so fixed as to remain so ; the instrument should be set on level 
ground, and at a distance from walls, trees, shrubs, &c. ; tall flowers should 
not be allowed to grow near the gauge. The gauge should be emptied 
daily at nine A.M., and the amount entered against the previous day. As 
the snowy season has begun, it is as well to give our readers Mr. Symons’ 
directions for the estimation of snow-fall. There are three modes for 
doing this: — 1. Melt what is caught in the funnel, and measure it as rain. 
2. Select a place where the snow has not drifted, invert the funnel, and 
turning it round, lift and melt what is enclosed. 3. Measure with a rule the 
average depth of snow, and take one-twelfth as the equivalent of water. 
On the subjects of when, where, and why rain is measured, our author is 
just as communicative of facts ascertained by practical experience and of 
suggestions which will be found useful by the student. But we have 
already quoted enough to show the value of his little work, and we must 
* Bain : How, When, Where, Why it is Measured.” By G. J. Symons, 
F.M.S. London: Stanford, 1867. 
