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Showing: 31-40 results of 59

INTRODUCTION Any ordinary, active man, provided he has reasonably good eyesight and nerve, can fly, and fly well. If he has nerve enough to drive an automobile through the streets of a large city, and perhaps argue with a policeman on the question of speed limits, he can take himself off the ground in an airplane, and also land—a thing vastly more difficult and dangerous. We hear a great deal about special tests for the... more...

Depth of Soil for Fruit. Would four feet of good loose soil be enough for lemons? Four feet of good soil, providing the underlying strata are not charged with alkali, would give you a good growth of lemon trees if moisture was regularly present in about the right quantity, neither too much nor too little, and the temperature conditions were favorable to the success of this tree, which will not stand as much frost as the orange. Temperatures... more...

INTRODUCTION THE Germans interpret their new national colours—black, red, and white—by the saying, "Durch Nacht und Blut zur licht." ("Through night and blood to light"), and no work yet written conveys to the thinker a clearer conception of all that the red streak in their flag stands for than this deep and philosophical analysis of "War" by Clausewitz. It reveals "War," stripped of all accessories, as the exercise of force for the... more...

CHAPTER 2.   Infantry Drill Regulations. The greatest lesson of the present war is that the keynote of success is discipline. In trenches the direct control of the men is even less than in extended order in open warfare, and only thoroughly disciplined troops with a trusted leader can hope to succeed. The successful officer will show anger or irritation only in rare cases, and then by design: he will know his men individually and be as... 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... more...


PREFACE To a good many of us the inventor is the true hero for he multiplies the working value of life. He performs an old task with new economy, as when he devises a mowing-machine to oust the scythe; or he creates a service wholly new, as when he bids a landscape depict itself on a photographic plate. He, and his twin brother, the discoverer, have eyes to read a lesson that Nature has held for ages under the undiscerning gaze of other men.... 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 series of letters which will contain... more...

THE ART OF WARFARE "The Art of War, like every other art, possesses its theory, its principles; otherwise, it would not be an art."—MARSHAL FOCH. The Art of War, like any other art, is based upon certain fixed principles, and there is no short cut which hurries the student to his goal. The long and laborious line of study is the only safe way, and there are many pitfalls to be avoided on the road. One of these pitfalls is dug by those who... more...

In an inventive tour de force that seldom, if ever, has been equalled for its brilliance and far-reaching consequences, James Watt radically altered the steam engine not only by adding a separate condenser but by creating a whole new family of linkages. His approach was largely empirical, as we use the word today. This study suggests that, despite the glamor of today's sophisticated methods of calculation, a highly developed intuitive sense,... more...

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 connections between the wire and rods. ()... more...