This revised edition of an extremely clear Navy training manual leaves nothing to be desired in its presentation. Thorough in its coverage of basic theory, from the lever and inclined plane to internal combustion engines and power trains, it requires nothing more than an understanding of the most elementary mathematics. Beginning with the simplest of machines — the lever — the text proceeds to discussions of the block and tackle (pulleys and hoists), wheel and axle, the inclined plane and the wedge, the screw, and different types of gears (simple, spur, bevel, herringbone, spiral, worm, etc.).
A chapter on the concept of work discusses the measurement of work, friction, and efficiency; this is followed by investigations of power, force, and pressure, with explanations of the uses of scales, balances, gauges, and barometers. The fundamentals of hydrostatic and hydraulic machines (such as the hydraulic braking system and the hydraulic press) are discussed in detail. The remaining chapters cover machine elements (bearings and springs), basic mechanisms (gear differential, couplings, cams, clutches), the internal combustion engine and power trains (including explanations of various transmission systems — synchromesh, auxiliary, etc.). Every concept is clearly defined, and discussions always build easily from elementary theory to specific applications familiar to anyone with the slightest interest in mechanics. Important concepts, machine components, and techniques are clearly illustrated in more than 200 diagrams, drawings, and cross-sections that reveal inner workings — all of these help to clarify even further an already clear and well-organized presentation. Although it was originally designed for use in U.S. Naval Training Schools, this book can be used to great advantage as a basic text in mechanical engineering in standard technical schools, and it will be immensely valuable even to lay readers who desire a basic knowledge of mechanics.
Bolle is vijf jaar als zijn vader doodgaat. Hij mist hem heel erg. Samen met zijn moeder probeert Bolle eraan te wennen dat zijn vader er niet meer is. Een ontroerend en troostrijk verhaal.
Reports of paranormal incidents are not uncommon in India. It is said that extreme suffering of human soul continues to manifest itself in various forms even after his death. The book collates seven stories that narrate the tales of seven such incidents in different parts of India, where deaths were the beginnings rather than the ends.
The First Transcontinental Railroad (known originally as the "Pacific Railroad" and later as the "Overland Route") was a railroad line built in the United States of America between 1863 and 1869 by the Central Pacific Railroad of California and the Union Pacific Railroad that connected its statutory Eastern terminus at Council Bluffs, Iowa/Omaha, Nebraska (via Ogden, Utah, and Sacramento, California) with the Pacific Ocean at Oakland, California on the eastern shore of San Francisco Bay opposite San Francisco. By linking with the existing railway network of the Eastern United States, the road thus connected the Atlantic and Pacific coasts of the United States by rail for the first time. The construction and operation of the line was authorized by the Pacific Railroad Acts of 1862 and 1864 during the American Civil War. Congress supported it with 30-year U.S. government bonds and extensive land grants of government-owned land. Completion of the railroad was the culmination of a decades-long movement to build such a line. It was one of the crowning achievements in the crossing of plains and high mountains westward by the Union Pacific and eastward by the Central Pacific. Opened for through traffic on May 10, 1869, with the driving of the "Last Spike" at Promontory Summit, Utah, the road established a mechanized transcontinental transportation network that revolutionized the population and economy of the American West. The Pacific Railroad constituted one of the most significant and ambitious American technological feats of the 19th century following in the footsteps of the building of the Erie Canal in the 1820s and the crossing of the Isthmus of Panama by the Panama Railroad in 1855 and this book is the pictorial story of this amazing feat and the individuals and driving forces behind it.
Joe and Frank are vacationing in a Rocky Mountain resort when suddenly a strange green light brightens up the sky. Three kidnappings follow.
Are they alien abductions or the work of down-to-earth criminals?