Technology & Engineering Books

APPARATUS 1. 1. Carbon-Zinc Cell. Fig. 1. If you have some rubber bands you can quickly make a cell out of rods of zinc and carbon. The rods are kept apart by putting a band, B, around each end of both rods. The bare wires are pinched under the upper bands. The whole is then bound together by means of the bands, A, and placed in a tumbler of fluid, as given in . This method does not make first-class... more...

HOW NEWSPAPERS ARE MADE. We will suppose that it is a great newspaper, in a great city, printing daily 25,000, or more, copies. Here it is, with wide columns, with small, compact type, with very little space wasted in head lines, eight large pages of it, something like 100,000 words printed upon it, and sold for four cents—25,000 words for a cent. It is a great institution—a power greater than a... more...

THE FARMER AT HOME. The new towns, or suburbs which spring up every year in the neighbourhood of London, are all built upon much the same plan. Whole streets of houses present exact duplicates of each other, even to the number of steps up to the front door and the position of the scraper. In the country, where a new farmhouse is erected about once in twenty years, the styles of architecture are as... more...

ELECTRICITY AND MATTER My Dear Son: You are interested in radio-telephony and want me to explain it to you. I’ll do so in the shortest and easiest way which I can devise. The explanation will be the simplest which I can give and still make it possible for you to build and operate your own set and to understand the operation of the large commercial sets to which you will listen. I’ll write you a... more...

THE MEN BEHIND THE MACHINES I MACHINES. AS SEEN FROM A MEADOW It would be difficult to find anything in the encyclopedia that would justify the claim that we are about to make, or anything in the dictionary. Even a poem—which is supposed to prove anything with a little of nothing—could hardly be found to prove it; but in this beginning hour of the twentieth century there are not a few of us—for... more...

Ice for Commercial Purposes ICE for commercial purposes is obtained in two ways: either by cutting during the winter time from our lakes and rivers and storing in large Ice Storage Houses located alongside, or by freezing pure clean water by means of artificial refrigeration. All authorities are agreed that artificial ice is more sanitary than natural ice and it is only a matter of time when the use of... more...

Introduction The art and science of agriculture embrace most intentional human efforts to control biological activity so as to produce plants and animals of the sort wanted, when wanted. Rubber plantations, cattle ranches, vegetable gardens, dairy farms, tree farms, and a host of similar enterprises all represent human efforts to compel nature to serve man. Those who undertake agriculture have had,... more...

MY EXCUSE My sixtieth birthday is a thing of yesterday, and I have, therefore, more than half descended the western slope. I have no quarrel with life or with time, for both have been polite to me; and I wish to give an account of the past seven years to prove the politeness of life, and to show how time has made amends to me for the forced resignation of my professional ambitions. For twenty-five... more...

INTRODUCTION Since the earliest communities of human beings first struggled for supremacy and protection, the principles of warfare have remained unchanged. New methods have been evolved and adopted with the progress of science, but no discovery, save perhaps that of gunpowder, has done so much in so short a time to revolutionize the conduct of war as aviation, the youngest, yet destined perhaps to be... more...

I COMMUNICATION AMONG THE ANCIENTS     Signaling the Fall of Troy—Marine Signaling among the    Argonauts—Couriers of the Greeks, Romans, and    Aztecs—Sound-signaling—Stentorophonic Tube—The Shouting    Sentinels—The Clepsydra—Signal Columns—Indian Fire and Smoke    Signals. It was very early in the history of the world that man began to feel the urgent need of... more...