ON THE ART OF SWIMMING.
In Answer to some Inquiries of M. Dubourg[ [2] on the Subject.
I am apprehensive that I shall not be able to find leisure for making all the disquisitions and experiments which would be desirable on this subject. I must, therefore, content myself with a few remarks.
The specific gravity of some human bodies, in comparison to that of water, has been examined by M. Robinson, in our Philosophical Transactions, volume 50, page 30, for the year 1757. He asserts, that fat persons, with small bones, float most easily upon water.
The diving bell is accurately described in our Transactions.
When I was a boy, I made two oval pallets, each about ten inches long, and six broad, with a hole for the thumb, in order to retain it fast in the palm of my hand. They much resembled a painter's pallets. In swimming, I pushed the edges of these forward, and I struck the water with their flat surfaces as I drew them back: I remember I swam faster by means of these pallets, but they fatigued my wrists. I also fitted to the soles of my feet a kind of sandals; but I was not satisfied with them, because I observed that the stroke is partly given by the inside of the feet and the ankles, and not entirely with the soles of the feet.
We have here waistcoats for swimming, which are made of double sail cloth, with small pieces of cork quilted in between them.
I know by experience, that it is a great comfort to a swimmer who has a considerable distance to go, to turn himself sometimes on his back, and to vary in other respects the means of procuring a progressive motion.
When he is seized with the cramp in the leg, the method of driving it away is to give to the parts affected a sudden, vigorous and violent shock; which he may do in the air as he swims on his back.
During the great heats of summer, there is no danger in bathing, however warm we may be, in rivers which have been thoroughly warmed by the sun. But to throw one's self into cold spring water, when the body has been heated by exercise in the sun, is an imprudence which may prove fatal. I once knew an instance of four young men, who, having worked at harvest in the heat of the day, with a view of refreshing themselves, plunged into a spring of cold water; two died upon the spot, a third the next morning, and the fourth recovered with great difficulty. A copious draught of cold water, in similar circumstances, is frequently attended with the same effect in North America.