Page:Popular Science Monthly Volume 28.djvu/497

Rh she can take care of 800 or more spindles and spin threads the aggregate length of which would be more than 2,000 miles.

On these machines cotton yarn has been spun so fine that one pound of cotton would make a thread 335 miles long, and as a feat threads have been so fine that a pound of cotton would reach nearly 5,000 miles!

To go back to our two cents' worth of cotton, which has been converted into yarn. It is subjected to the action of several machines before it reaches the loom, where it is converted into cloth. Weaving, like spinning, is old, and some sort of machinery has always been employed in the process, but the power-loom of our factories is a modern invention. I sometimes think it is the most wonderful machine used. To make one yard of cloth, a shuttle carrying the filling-thread is thrown across the web perhaps 1,500 times, at the rate of a hundred crossings a minute.

There are looms which weave cloth more than three yards wide. There may be nearly 10,000 warp-threads in cloth of this width, and 5,000 filling-threads in a yard carried across the web at the rate of nearly a hundred throws a minute.

The art of printing has always been recognized as one of the great inventions of man. It is over four hundred years old, but after its first introduction very little improvement was made until the present century. Since then it has presented a rapid succession of the highest efforts of mechanical genius. I shall not attempt to follow their history or describe their character; but it is interesting to know that they have been made almost wholly by English or American inventors, and that more has been done in this country than in England. The wonder of modern printing is that it can be done so cheaply. You have all seen the series of publications by the Harpers called the "Franklin Square Library." I bought a copy for ten cents, the regular price. It contained thirty-six printed pages. I had the curiosity to estimate the number of words on a page and calculated it roughly at 2,000. That would give for the whole book 72,000 words, all for ten cents. Can you form a conception of the number of inventions which has made such an achievement possible? I think a modern daily newspaper is, however, one of the greatest wonders of the age.

I buy a morning paper, the "Boston Herald," for instance, for two cents. I read it on my way to Boston in the horse-cars and abandon it at the end of the trip, not because it is worthless, but because I have obtained from it what I wanted and it will not pay to preserve it for any other person or for future use. Now, what do I buy for my two cents? The physical thing that I buy is a sheet of paper and a certain amount of printers' ink impressed upon the surface of the paper in the shapes of letters and words. It is a wonderful fact that man can spread out the fibers of various vegetable substances into a thin,