Mechanical arts

“ Sometimes they connect a moving wheel with the piston used in churning. In another place you see a cradle rocked with a motion the more gentle as it is produced by a fall of water moderated [Pg 40] with art. In short, a stranger who visits their country, perceives, at every step, the extraordinary turn of these people for the mechanical arts. ”

“ In following the course of invention and rediscovery during the middle ages, and in subsequent times, we see two main causes of the superiority of our own useful arts to those of the ancients—the extended application of mechanical and chemical science. The discovery of the various problems in mechanics, which paved the way for the multiplication of human force, and the introduction of new motor powers, occupied chiefly the latter half of the sixteenth and the seventeenth century. ”

“ Mechanical laws and mechanical powers have a wide range of influence in the arts of design; for how shall a man embellish his work appropriately who knows not the former, or how economize in the use and application of machinery, without being conversant with the latter? ”

“ Mechanical engineering, as we understand it, could only fairly start in its wonderful progress after the mechanic had found ways of utilizing natural forces and energies, and of making the tools with which to produce these prime motors, through the operation of which all the arts could be given application in the production of wealth, multiplying the power of the unaided hand by making it in the performance of work the guide of greater powers, rather than the tool itself. ”

“ MECHANIC ARTS.—In giving the history of the state of the mechanic arts as they were exercised at an early period of the settlement of this country, I shall present a people, driven by necessity to perform works of mechanical skill, far beyond what a person enjoying all the advantages of civilization would expect from a population placed in such destitute circumstances. ”

“ The ancients considered Mechanics in a twofold respect; as rational, which proceeds accurately by demonstration, and practical. To practical Mechanics all the manual arts belong, from which Mechanics took its name. But as artificers do not work with perfect accuracy, it comes to pass that Mechanics is so distinguished from Geometry, that what is perfectly accurate is called Geometrical, what is less so is called Mechanical. But the errors are not in the art, but in the artificers. ”

“ Forming a complete course of Mechanical Engineering and Architectural Drawing. From the French of M. Armengaud the elder, Prof. of Design in the Conservatoire of Arts and Industry, Paris, and MM. Armengaud the younger and Amouroux, Civil Engineers. Rewritten and arranged, with additional matter and plates, selections from and examples of the most useful and generally employed mechanism of the day. By William Johnson, Assoc. Inst. C. E., Editor of “The Practical Mechanic’s Journal.” Illustrated by 50 folio steel plates and 50 wood-cuts. ”

“ In fact, physics teaches us that the hand is a combination of the six mechanical powers--the lever, the wedge, the wheel and axle, the pulley, the screw, and the inclined plane. But the mechanical effect is always depreciated. ”

“ It must be admitted, too, that the sense of the reality of this separation has been felt not only by Engineers or others actually engaged in machine design, but also by those theoretical writers who have had any practical knowledge of machinery, in spite of the increasing tendency in the treatment of mechanical science to thin away machine-problems into those of pure mechanics. ”

“ The sciences we have been considering under the general name of mechanics, which is derived from a Greek word that means to contrive, invent, construct, have much to do with machinery, with the methods of construction, the propelling forces, and the phenomena produced. There were machinists and some simple machines propelled by human or brute force, by weights and springs, by falling or running water, and air in motion before the laws of motion and forces were understood, or the rude mechanic arts began to assume the character of a science. ”

“ The machine tools did all the working (for the thinking had been embodied in them beforehand) , and they turned out all manner of geometrical forms with the utmost correctness. This sort of training educated the faculties of the lads, and trained their ideas to the perception of exactness of form, at the same time that it gave them an intimate acquaintance with the nature of the materials employed in mechanical structures. The rapidity with which they thus acquired the efficiency of thoroughly practical mechanics was surprising. ”

“ The study of kinematics has been considered for nearly 80 years as a necessary part of the mechanical engineer's training, as the dozens of textbooks that have been published over the years make amply clear. ”

“ There is an admirably condensed treatise on the mechanical powers, containing all the problems of use in construction, with tables of the mechanical properties of materials. In mechanical drawing there are directions for the most complicated drawings, going up to the last improvements in the steam-engine. ”

“ It would be absurd to deny all recognition or knowledge of mechanical causation to people who show so much ingenuity in the construction of houses, boats, weapons, and a great variety of mechanical devices, such as traps, and in other operations involving the intelligent application of mechanical principles. ”

“ How to Experiment with Machines.—Any one who possesses the slightest bent for mechanics can work out improvements on devices like egg-beaters and monkey-wrenches and feel their way as they go along.
But when it comes to designing and building real machines where numerous levers, gears, and springs are combined to make a working unit you should by all means read up on the subjects of work, energy and power, learn about the six mechanical powers—and the action of machines in general. ”

“ The man who aspires to construct any great mechanical engineering work, like the Brooklyn Bridge, for example, must know the exact mechanical power of every piece of machinery he employs, as also the exact mechanical value of every piece of iron that enters into the structure; and these things he cannot know unless he is familiar with the entire series of iron manipulations, from those of the foundery to those of the machine-tool shop. ”

“ The story of machinery, from primitive man’s first attempts to augment his physical powers with mechanical aids down to the present era of gigantic, steel-muscled machinery and marvelously intricate mechanisms, is the story of human progress. ”

“ The perfection of modern machine-tools is such that the utmost possible precision is secured, and the mechanical engineer can calculate on a degree of exactitude that does not admit of a deviation beyond the thousandth part of an inch. ”

“ We observe that irregular and complex forms, in the production of which mechanical appliances could not be used to advantage, are modeled with as much grace of contour and perfection of surface as are the simpler shapes that could be turned upon a wheel, and we conclude that with this remarkable people the hand and the eye were so highly educated that mechanical aids were not indispensable. ”

“ This shows within what distinct limits machine-problems lie, and that they allow themselves to be readily separated from the general problems of Mechanics, as we have already maintained.
While the science of Mechanics examines motion caused in the most general cases by the action of mechanical forces, Machine-mechanics occupies itself with certain special cases only, with motions produced by a limited circle of means. It draws its first laws from the same fountain as Mechanics, to which, as the more comprehensive science, it is subordinate. ”

“ The slightest glance, however, must convince us that mechanical power and mechanical skill, as they are now exhibited in Europe and America, mark an epoch in human history worthy of all admiration. Machinery is made to perform what has formerly been the toil of human hands, to an extent that astonishes the most sanguine, with a degree of power to which no number of human arms is equal, and with such precision and exactness as almost to suggest the notion of reason and intelligence in the machines themselves. ”

“ Carpentry is distinguished for its corners and angles, turnery for its spherical, cylindrical, and eccentric forms. In these forms Nature abounds and delights, and it is in these forms that the rhythm of mechanics exists. It is by the Turners that the arts are supplied with a thousand and one things of use and beauty. The machines, great and small, from the locomotive to the stocking-knitter—without which the work of the modern world could not be done—these wonderful contrivances, seemingly more cunning than the hand of man, owe their very existence to the turning-lathe. ”

“ As, however, the actual machinery itself, deriving its existence from various sources, and having its own characteristic features and methods of classification and treatment, forms a quite distinct and special subject, a separation of its scientific mechanical problems from those of Mechanics in general is possible, and indeed has already been made. ”

“ As users of these tools we cannot begin to compare with the skilled workman of ancient days. Our progress is shown not in the development of skill, but in the loss of it. We have taken the tool out of the human hand and put it into an inanimate machine. It is only very recently that the tool was delivered to the machine and that act marked the dawn of the present remarkable mechanical era. ”

“ So, also, in developing the rise of a machine, a coarse instrument or a toy may be recognized as the germ of that production of mechanical genius, whose power and usefulness have stimulated our curiosity to mark its changes and to trace its origin. ”

“ Yet this remarkable contrivance, with all its massive steel beams and chains and cog wheels, employs no other principles than the simple ones of lever and pulley and inclined plane that we have just examined. The power that must be applied to produce a given effect may be calculated to a nicety. The capacities of the machine are fully predetermined in advance of its actual construction. But of course this is equally true of every other form of power-transmitter with which the modern mechanical engineer has to deal. ”

“ We are far from having described all the implements of the mechanical engineer, or even all the more interesting ones; for example, we have given no account of the powerful lathes in which great masses of iron are turned, or of the analogous machines, which, with so much accuracy, shape the internal surfaces of the cylinders of steam engines, of cannons, &c. ”

“ We see this very clearly in the names of the different parts of machinery, which are taken from the names of similar parts in the human frame. Almost every member of the body is used in mechanical terminology. ”

“ In course of time various modifications of the machine were introduced—such as the planing machine, the wheel-cutting machine, and other beautiful tools on the slide-rest principle,—the result of which has been that extraordinary development of mechanical production and power which is so characteristic a feature of the age we live in. ”

“ A.--The mechanical powers are certain contrivances, such as the wedge, the screw, the inclined plane, and other elementary machines, which convert a small force acting through a great space into a great force acting through a small space. ”

“ To the learner, practice with hand tools is especially advantageous, inasmuch as the strain due to the cut is felt by the operator; hence, the effects of alterations in the shape of the tools, its height or position with relation to the work, and also the resistance of the metal to severance, are more readily understood and appreciated than is the case where the tool is held in a slide rest or other mechanical device. ”

“ Mechanical engineering is a profession whose medium of endeavor lies in the metals. Mechanical engineers shape things out of iron or steel or brass or other metal compositions, and put these things into engines or machines for service. ”

“ The improvement so much to be desired, will speedily follow upon the discontinuance of grinding. Recourse must then be had to the natural process. The surface plate and the scraping instrument will come into constant use, affording the certain and speedy means of attaining any degree of truth which may be required. A higher standard of excellence will be gradually established, the influence of which will be felt throughout all mechanical operations, while, to the mechanic himself, a new field will be open, in which he will find ample scope for the exercise of skill, both manual and mental. ”

“ We can go on endlessly with our speculations on the evolution of tools and machinery up to the time when historians began to record the mechanical achievements of man. Unfortunately even after historians began to write they were so filled with admiration for the destructive work of man that they had no time to record his constructive work. ”

“ Few mechanics have any distinct knowledge of the method to be pursued for obtaining it, nor do practical men sufficiently advert, either to the immense importance, or to the comparative facility of the acquisition. ”

“ For from hence are easily deduced the forces of machines, which are compounded of wheels, pullies, levers, cords, and weights, ascending directly or obliquely, and other mechanical powers; as also the force of the tendons to move the bones of animals. ”

“ Such are among the triumphs of modern mechanical engineering, due in a great measure to the perfection of the tools by means of which all works in metal are now fashioned. These tools are themselves among the most striking results of the mechanical invention of the day. They are automata of the most perfect kind, rendering the engine and machine-maker in a great measure independent of inferior workmen. For the machine tools have no unsteady hand, are not careless nor clumsy, do not work by rule of thumb, and cannot make mistakes. ”