Page:The Atlantic Monthly, Volume 18.djvu/140

132, that I had four hundred and fifty feet, or one hundred and fifty yards, of the most brilliant and beautiful golden silk I had ever seen.

During all this operation the spider had remained perfectly quiet, but finally put an end to my proceedings by grasping the line with the tip of one of her hind legs so that it snapped. I was tired, however, and contented myself with the quantity already obtained, which now formed a raised band of gold upon the quill. This specimen is now in my possession, but has been removed from the quill to ascertain its weight, which is one third of a grain.

It is worthy of notice, perhaps, that in all this was involved no new fact, but only a happy deduction from one known ages ago; namely, that a spider, when dropping, leaves her line attached, and so allows it to be drawn from her body. Nothing was more natural than to simply reverse the position of the fixed point, and, instead of letting the spider go away from the end of her line, to take the end of her line away from her. So natural, indeed, did it seem, that my gratification at having been (as was then supposed) the first to do it was, on reflection, mixed with surprise that no one had ever thought of it before, and I am very glad to find that at least four individuals have, within the last century, pulled silk out of a spider, though of these only one, whose researches I hope to make known, regarded the matter as anything more than a curious experiment.

I had never before seen such a spider, nor even paid attention to any geometrical species; though one large black and yellow variety is, or used to be, common enough in our fields at the North. Neither had I ever heard of such a method of obtaining silk. But though my first specimen was not preserved, and a second was never seen on Folly Island, yet I was so impressed with its size and brilliant colors, and especially with the curious brushes of black hairs on its legs, that when, during the following summer, another officer described to me a great spider which was very common on Long Island, where he was stationed, I knew it was the same, and told him what I had done the year before, adding that I was sure something would come of it in time.

With leisure and many spiders at his command, this officer improved upon my suggestion, by substituting for my quill turned in the fingers a wooden cylinder worked by a crank, and by securing, at a proper distance, (between pins, I think,) one or more spiders, whose threads were guided between pins upon the cylinder. He thus produced more of the silk, winding it upon rings of hard rubber so as to make very pretty ornaments. With this simple machine I wound the silk in two grooves cut on a ring of hard rubber and parallel except at one point, where they crossed so as to form a kind of signet. Another officer now suggested and put in operation still another improvement, in the shape of the "gear-drill-stock" of our armorer's chest. This, being a machine for drilling iron, was rough in its construction and uneven in its action, but, having cog-wheels, a rapid and nearly steady motion could be given to its shaft. To this shaft he attached a little cross of rubber, and covered it with silk, which was of a silver-white color instead of golden-yellow, as in other cases. The difference in color was then supposed to depend upon individual peculiarities, but the true explanation will be given farther on. With this gear-drill-stock, upon a larger ring, one inch in diameter and three eighths of an inch in width, in a groove upon its periphery one fourth of an inch in width, and across the sides of the ring in two directions, I wound three thousand four hundred and eighty-four yards, or nearly two miles, of silk. The length was estimated by accurately determining the different dimensions of the ring where wound upon, and multiplying by this the number of revolutions of the cylinder per minute (170), and this product again by the number of minutes of actual winding (285), deducting from the gross time of winding