14 ANNIVERSARY ADDRESS. 
belief in this became so general that farmers began the practice of 
making large heaps of brushwood on each farm, and when they 
wanted rain lighting them all together. I cannot find any refer- 
ence to the results of this system in the Smithsonian publications, 
in which almost every subject of this kind is dwelt upon ; but the 
practice seems to have been given up. 
In 1870, Mr. Edward Powers, 0.E., in a small volume entitled 
“War and the Weather, or the artificial production of Rain,” en- 
deavours to prove that rain can be produced by human agency, 
particularly by heavy discharges of artillery, and cites a number of 
instances in which great battles have been followed by a speedy 
downfall of rain. He mentions six cases of this kind in the Mexi- 
can war, 1846 and 1847; nine cases of battles or skirmishes 
followed by rain in the American Civil War of 1861, forty such 
eases in 1862, thirty in 1863, twenty-eight for 1864, and six for 
1865; eighteen similar cases from the great battles fought in 
Europe during the past century, making a total of 137; and he 
says if these facts are insufficient to convince, it would be vain t0 
expect to do so with a greater number. The meteorological editor 
of Silliman’s Journal, in reviewing this book, justly says “ that the 
writer has omitted to consider many necessary points in the proof, 
for in those parts of the earth in which the battles cited were 
fought, rain falls upon an average once in three days, so that the 
average interval between rains would be about two days. Now, 
battles are seldom commenced during rain ; generally some hous 
elapse to dry the ground before the battle begins. Rain ought, 
therefore, to fall within about day after a battle. Mr. Powers 
takes no precise account of und arn of the interval between the 
end of the battles and the commencement of rain ; nor does he 
attempt to show that the battle shortens this period ; and, a : 
over, he says nothing of the cases opposed to his theory. In order | 
to complete the proof, a much more careful analysis of the facts vs ; 
required. We are inclined to the opinion that great battles . 
exert some influence in the production of rain, but we cand? | 
accept Mr. Powers’ discussion of the facts as proof.” ‘This opinio™ 
