Mechanical Engineers

"Mihajlo Mesarovic and Eduard Pestel have made a deliberate attempt to gain approbation from the skeptical segment of the intellectual community and to disassociate their work from that of Forrester and Meadows."

"The value of global modelling has been severely restricted by poor appreciation of the constraints under which governments and politicians operate. Equally, the value of governments and politicians has been severely restricted by largely ignoring the very real but less immediate problems tackled by modellers."

"Our world model was built specifically to investigate five major trends of global concern – accelerating industrialization, rapid population growth, widespread malnutrition, depletion of nonrenewable resources, and a deteriorating environment. The model we have constructed is, like every model, imperfect, oversimplified, and unfinished... Our conclusions are : (1.) If the present growth trends in world population, industrialization, pollution, food production, and resource depletion continue unchanged, the limits to growth on this planet will be reached sometime within the next one hundred years. The most probable result will be a rather sudden and uncontrollable decline in both population and industrial capacity..."

"The objects of instruction in purely scientific mechanics and physics are, first, to produce in the student that improvement of the understanding which results from the cultivation of natural knowledge, and that elevation of mind which flows from the contemplation of the order of the universe; and secondly, if possible, to qualify him to become a scientific discoverer."

"We have... used the word stress to denote the mutual action between two portions of matter. This word was borrowed from common language, and invested with a precise scientific meaning by the late Professor Rankine to whom we are indebted for several other valuable scientific terms."

"Science Of Energetics. Although the mechanical hypothesis just mentioned may be useful and interesting as a means of anticipating laws, and connecting the science of thermodynamics with that of ordinary mechanics, still it is to be remembered that the science of thermodynamics is by no means dependent for its certainty on that or any other hypothesis, having been now reduced, to a system of principles, or general facts, expressing strictly the results of experiment as to the relations between heat and motive power. In this point of view the laws of thermodynamics may be regarded as particular cases of more general laws, applicable to all such states of matter as constitute Energy, or the capacity to perform work, which more general laws form the basis of the science of energetics, — a science comprehending, as special branches, the theories of motion, heat, light, electricity, and all other physical phenomena."

"Hypothesis Of Molecular Vortices. In thermodynamics as well as in other branches of molecular physics, the laws of phenomena have to a certain extent been anticipated, and their investigation facilitated, by the aid of hypotheses as to occult molecular structures and motions with which such phenomena are assumed to be connected. The hypothesis which has answered that purpose in the case of thermodynamics, is called that of "molecular vortices," or otherwise, the "centrifugal theory of elasticity. (On this subject, see the Edinburgh Philosophical Journal, 1849; Edinburgh Transactions, vol. xx.; and Philosophical Magazine, passim, especially for December, 1851, and November and December, 1855.)"

"It is possible to express the laws of thermodynamics in the form of independent principles, deduced by induction from the facts of observation and experiment, without reference to any hypothesis as to the occult molecular operations with which the sensible phenomena may be conceived to be connected; and that course will be followed in the body of the present treatise. But, in giving a brief historical sketch of the progress of thermodynamics, the progress of the hypothesis of thermic molecular motions cannot be wholly separated from that of the purely inductive theory."

"But in practical science, the question is—What are we to do?—a question which involves the necessity for the immediate adoption of some rule of working. In doubtful cases, we cannot allow our machines and our works of improvement to wait for the advancement of science; and if existing data are insufficient to give an exact solution of the question, that approximate solution must be acted upon which the best data attainable show to be the most probable. A prompt and sound judgment in cases of this kind is one of the characteristics of a Practical Man in the right sense of that term."

"In theoretical science, the question is—What are we to think? and when a doubtful point arises, for the solution of which either experimental data are wanting, or mathematical methods are not sufficiently advanced, it is the duty of philosophic minds not to dispute about the probability of conflicting suppositions, but to labour for the advancement of experimental inquiry and of mathematics, and await patiently the time when they shall be adequate to solve the question."

"In treating of the practical application of scientific principles, an algebraical formula should only be employed when its shortness and simplicity are such as to render it a clearer expression of a proposition or rule than common language would be, and when there is no difficulty in keeping the thing represented by each symbol constantly before the mind."

"[T]he symbols of algebra, when employed in abstruse and complex theoretical investigations, constitute a sort of thought-saving machine, by whose aid a person skilled in its use can solve problems respecting quantities, and dispense with the mental labour of thinking of the quantities denoted by the symbols, except at the beginning and the end of the operation."

"Sir John Herschel's "Outlines of Astronomy"—[is] a work in which one of the most profound mathematicians in the world has succeeded admirably in divesting of all mathematical intricacy the explanation of the principles of that natural science which employs higher mathematics most."

"In the original discovery of a proposition of practical utility, by deduction from general principles and from experimental data, a complex algebraical investigation is often not merely useful, but indispensable; but in expounding such a proposition as a part of practical science, and applying it to practical purposes, simplicity is of the importance:—and... the more thoroughly a scientific man has studied higher mathematics, the more fully does he become aware of this truth—and... the better qualified does he become to free the exposition and application of principles from mathematical intricacy."

"The third and intermediate kind of instruction, which connects the first two... relates to the application of scientific principles to practical purposes. It qualifies the student to plan a structure or a machine for a given purpose, without the necessity of copying some existing example, and to adapt his designs to situations to which no existing example affords a parallel. It enables him to compute the theoretical limit of the strength or stability of a structure, or the efficiency of a machine of a particular kind—to ascertain how far an actual structure or machine fails to attain that limit—to discover the cause of such shortcomings—and to devise improvements for obviating such causes; and it enables him to judge how far an established practical rule is founded on reason, how far on mere custom, and how far on error."

"The ascertainment and illustration of truth are the objects; and structures and machines are looked upon merely as natural bodies are; namely, as furnishing experimental data for the ascertaining of principles and examples for their application."

"In this branch of study exactness is an essential feature; and mathematical difficulties must not be shrunk from when the nature of the subject leads to them."

"Mechanical knowledge may... be distinguished into three kinds; purely scientific knowledge, purely practical knowledge, and that intermediate kind of knowledge which relates to the application of scientific principles to practical purposes, and which arises from understanding the harmony of theory and practice."

"Some of the evils which are caused by the fallacy of an incompatibility between theory and practice having been described, it must now be admitted, that at the present time those evils show a decided tendency to decline. The extent of intercourse, and of mutual assistance, between men of science and men of practice, the practical knowledge of scientific men, and the scientific knowledge of practical men, have been for some time steadily increasing; and that combination and harmony of theoretical and practical knowledge—that skill in the application of scientific principles to practical purposes, which in former times was confined to a few remarkable individuals, now tends to become more generally diffused."

"The ill-success of the projects of misdirected ingenuity has very naturally the effect of driving those men of practical skill, who, though without scientific knowledge, possess prudence and common sense, to the opposite extreme of caution, and of inducing them to avoid all experiments, and to confine themselves to the careful copying of successful existing structures and machines; a course which, although it avoids risk, would, if generally followed, stop the progress of all improvement. A similar course has sometimes... been adopted by men possessed of scientific as well as practical skill: such men having, in certain cases, from deference to popular prejudice, or from a dread of being reputed us theorists, considered it advisable to adopt the worse and customary design for a work in preference to a better but unusual design."

"The most absurd of all their delusions commonly called the , or to speak more accurately, the inexhaustible source of power—is, in various forms, the subject of several patents in each year."

"Another evil, and one of the worst which arises from the separation of theoretical and practical knowledge, is the fact that a large number of persons, possessed of an inventive turn of mind and of considerable skill in the manual operations of practical mechanics, are destitute of that knowledge of scientific principles which is requisite to prevent their being misled by their own ingenuity. Such men too often spend their money, waste their lives, and it may be lose their reason in the vain pursuits of visionary inventions, of which a moderate amount of theoretical knowledge would be sufficient to demonstrate the fallacy ; and for want of such knowledge, many a man who might have been a useful and happy member of society, becomes a being than whom it would be hard to find anything more miserable. The number of those unhappy persons — to judge from the patent-lists, and from some of the mechanical journals — must be much greater than is generally believed."

"But a class of structures fraught with much greater evils exist in great abundance throughout the country—namely, those in which the faults of an unscientific design have been so far counteracted by massive strength, good materials, and careful workmanship, that a temporary stability has been produced, but which contain within themselves sources of weakness, obvious to a scientific examination... that must inevitably cause their destruction within a limited number of years."

"With respect to those works which, from unscientific design, give way during or immediately after their erection, I shall say little; for with all their evils, they add to our experimental knowledge, and convey a lesson, though a costly one."

"[O]f that scientifically practical skill which produces the greatest effect with the least possible expenditure of material and work, the instances are comparatively rare. In too many cases we see the strength and the stability which ought to be given by the skilful arrangement of the parts of a structure supplied by means of clumsy massiveness, and of lavish expenditure of material, labour, and money; and the evil is increased by a perversion of the public taste, which causes works to be admired, not in proportion to their fitness for their purposes, or to the skill evinced in attaining that fitness, but in proportion to their size and cost."

"The evil influence of the supposed inconsistency of theory and practice upon speculative science, although much less conspicuous than it was in the ancient and middle ages, is still occasionally to be traced. This it is which opposes the mutual communication of ideas between men of science and men of practice, and which leads scientific men sometimes to employ, on problems that can only be regarded as ingenious mathematical exercises, much time and mental exertion that would be better bestowed on questions having some connection with the arts, and sometimes to state the results of really important investigations on practical subjects in a form too abstruse for ordinary use; so that the benefit which might be derived from their application is for years lost to the public; and valuable practical principles which might have been anticipated by reasoning, are left to be discovered by slow and costly experience."

"A hypothetical theory is necessary, as a preliminary step, to reduce the expression of the phenomena to simplicity and order before it is possible to make any progress in framing an abstractive theory."

"A physical theory, like an abstract science, consists of definitions and axioms as first principles, and of propositions, their consequences; but with these differences:—first, That in an abstract science, a definition assigns a name to a class of notions derived originally from observation, but not necessarily corresponding to any existing objects of real phenomena, and an axiom states a mutual relation amongst such notions, or the names denoting them; while in a physical science, a definition states properties common to a class of existing objects, or real phenomena, and a physical axiom states a general law as to the relations of phenomena; and, secondly,—That in an abstract science, the propositions first discovered are the most simple; whilst in a physical theory, the propositions first discovered are in general numerous and complex, being formal laws, the immediate results of observation and experiment, from which the definitions and axioms are subsequently arrived at by a process of reasoning differing from that whereby one proposition is deduced from another in an abstract science, partly in being more complex and difficult, and partly in being to a certain extent tentative, that is to say, involving the trial of conjectural principles, and their acceptance or rejection according as their consequences are found to agree or disagree with the formal laws deduced immediately from observation and experiment."

"An essential distinction exists between two stages in the process of advancing our knowledge of the laws of physical phenomena; the first stage consists in observing the relations of phenomena, whether of such as occur in the ordinary course of nature, or of such as are artificially produced in experimental investigations, and in expressing the relations so observed by propositions called formal laws. The second stage consists in reducing the formal laws of an entire class of phenomena to the form of a science; that is to say, in discovering the most simple system of principles, from which all the formal laws of the class of phenomena can be deduced as consequences."

"This law (regarding the theoretical efficiency of heat engines by Mr. Joule), and the law of the maximum efficiency of heat engines, are particular cases of a general law which regulates all transformation of energy, and is the basis of the Science of Energetics."

"Discrepancy between theory and practice, which in sound physical and mechanical science is a delusion, has a real existence in the minds of men; and that fallacy, through rejected by their judgments, continues to exert and influence over their acts."

"The hypothesis of molecular vortices is defined to be that which assumes — that each atom of matter consists of a nucleus or central point enveloped by an elastic atmosphere, which is retained in its position by attractive forces, and that the elasticity due to heat arises from the centrifugal force of those atmospheres revolving or oscillating about their nuclei or central points. According to this hypothesis, quantity of heat is the vis viva of the molecular revolutions or oscillations."

"Earth, thou grain of sand on the shore of the Universe of God; thou Bethlehem, amongst the princely cities of the heavens; thou art, and remainest, the Loved One amongst ten thousand suns and worlds, the Chosen of God! Thee will He again visit, and then thou wilt prepare a throne for Him, as thou gavest Him a manger cradle; in His radiant glory wilt thou rejoice, as thou didst once drink His blood and tears, and mourn His death! On thee has the Lord a great work to complete."

"In science its main worth is temporary, as a stepping-stone to something beyond. Even the Principia, as Newton, with characteristic modesty entitled his great work, is truly but the beginning of a natural philosophy, and no more an ultimate work than Watt's steam-engine, or Arkwright's spinning-machine."

"Almost everybody is sure... that it is proceeding with unprecedented speed; and... that its effects will be more radical than anything that has gone before. Wrong, and wrong again. Both in its speed and its impact, the information revolution uncannily resembles its two predecessors... The first industrial revolution, triggered by James Watt's improved steam engine in the mid-1770s... did not produce many social and economic changes until the invention of the railroad in 1829... Similarly, the invention of the computer in the mid-1940s... it was not until 40 years later, with the spread of the Internet in the 1990s, that the information revolution began to bring about big economic and social changes... the same emergence of the “super-rich” of their day, characterized both the first and the second industrial revolutions... These parallels are close and striking enough to make it almost certain that, as in the earlier industrial revolutions, the main effects of the information revolution on the next society still lie ahead."

"These foundations decisively changed incentives for people and impelled the engines of prosperity, paving the way for the Industrial Revolution. First and foremost, the Industrial Revolution depended on major technological advances exploiting the knowledge base that had accumulated in Europe during the past centuries. It was a radical break from the past, made possible by scientific inquiry and the talents of a number of unique individuals. The full force of this revolution came from the market that created profitable opportunities for technologies to be developed and applied. It was the inclusive nature of markets that allowed people to allocate their talents to the right lines of business. It also relied on education and skills, for it was the relatively high levels of education, at least by the standards of the time, that enabled the emergence of entrepreneurs with the vision to employ new technologies for their businesses and to find workers with the skills to use them. It is not a coincidence that the Industrial Revolution started in England a few decades following the Glorious Revolution. The great inventors such as James Watt (perfecter of the steam engine), Richard Trevithick (the builder of the first steam locomotive), Richard Arkwright (the inventor of the spinning frame), and Isambard Kingdom Brunel (the creator of several revolutionary steamships) were able to take up the economic opportunities generated by their ideas, were confident that their property rights would be respected, and had access to markets where their innovations could be profitably sold and used."

"It is not worth my while to manufacture in three countries only; but I can find it very worthwhile to make it for the whole world."

"I can think of nothing else than this machine."

"If the Steam Engine be the most powerful instrument in the hands of man, to alter the face of the physical world, it operates, at the same time, as a powerful moral lever in forwarding the great cause of civilization. ...If ...we are now met to consider of placing a monument to the memory of Mr. Watt beside the monuments of those who fell in the splendid victories of the last war, let it not be said that there is no connexion between the services of this modest and unobtrusive benefactor of his country, and the triumphs of the heroes which those monuments are destined to commemorate. ...It has been often said, that many of the great discoveries in science are due to accident; but it was well remarked by [Humphry Davy]... that this cannot be the case with the principal discovery of Mr. Watt. ... Again, it has frequently happened that those philosophers, who have made brilliant and useful discoveries... have only been able to turn their discoveries to the purpose of averting evils threatening, and often destroying, the precarious tenure of human existence. Thus Franklin disarmed the thunderbolt, and conducted it innocuous through our buildings, and close to our fire-sides—thus Jenner stripped a loathsome and destructive disease of its virulence, and rendered it harmless of devastation—thus [Davy]... sent the safety lamp into our mines to save... their useful inhabitants from the awful explosion of the fire damp. But the discovery of Mr. Watt went further: he subdued and regulated the most terrific power in the universe,—that power which, by the joint operation of pressure and heat, probably produces those tremendous convulsions of the earth, which in a moment subvert whole cities, and almost change the face of the inhabited globe. This apparently ungovernable power Mr. Watt reduced to a state of such perfect organization and discipline... that it may now be safely manœuvred and brought into irresistible action—irresistible, but still regulated, measured, and ascertained—or lulled into the most complete and secure repose, at the will of man, and under the guidance of his feeble hand. Thus one man directs it into the bowels of the earth, to tear asunder its very elements, and bring to light its hidden treasures; another places it upon the surface of the waters, to control the winds of heaven, to stem the tides, to check the currents, and defy the waves of the ocean; a third, perhaps and a fourth, are destined to apply this mighty power to other purposes, still unthought of and unsuspected, but leading to consequences, possibly not less important than those which it has already produced. ... those benefits, conferred by Mr. Watt on the whole civilized world, have been most experienced by his own country, which owes a tribute of national gratitude to a man, who has thus honoured her by his genius, and promoted her well being by his discoveries."

"Do good work."

"If we die we want people to accept it. We are in a risky business, and we hope that if anything happens to us, it will not delay the program. The conquest of space is worth the risk of life. Our God-given curiosity will force us to go there ourselves because in the final analysis, only man can fully evaluate the moon in terms understandable to other men."

"I am glad to learn that the Parliament Bill has been passed for the Darlington Railway. I am much obliged by the favourable sentiments you express towards me, and shall be happy if I can be of service in carrying into execution your plans."

"To tell you the truth although it would put £500 in my pockets to specify my own patent rails, I cannot do so after the experience I have had."

"I observe you have thought proper to insert the last number of the Philosophical Magazine your opinion that my attempts at the safety tubes and apertures were borrowed from what I have heard of Sir Humphrey Davy's researches. The principles upon which a safety lamp might be constructed I stated to several persons long before Sir Humphrey Davy came into this part of the country. The plan of such a lamp was seen by several and the lamp itself was in the hands of the manufacturers during the time he was here."

"George Stephenson told me as a young man that railways will supersede almost all other methods of conveyance in this country — when mail-coaches will go by railway, and railroads will become the great highway for the king and all his subjects. I know there are great and almost insurmountable difficulties to be encountered; but what I have said will come to pass as sure as you live."

"Left home in company with John Dixon to attend the internment of George Stephenson at Chesterfield. I fear he died an unbeliever. When I reflect on my first acquaintance with him and the resulting consequences my mind seems lost in doubt as to the beneficial results — that humanity has been benefited in the diminished use of horses and by the lessened cruelty to them, that much ease, safety, speed, and lessened expense in travelling is obtained, but as to the results and effects of all that railways had led my dear family into, being in any sense beneficial is uncertain."

"It will hereafter be scarcely believed that an invention so eminently scientific, and which could never have been derived but from the sterling treasury of science, should have been claimed on behalf of an engine-wright of Killingworth, of the name of Stephenson — a person not even possessing a knowledge of the elements of chemistry."

"This railway is the most absurd scheme that ever entered into the head of a man to conceive. Mr. Stephenson never had a plan — I do not believe he is capable of making one. He is either ignorant or something else which I will not mention. His is a mind perpetually fluctuating between opposite difficulties; he neither knows whether he is to make bridges over roads or rivers, or of one size or another; or to make embankments, or cuttings, or inclined planes, or in what way the thing is to be carried into effect. When you put a question to him upon a difficult point, he resorts to two or three hypothesis, and never comes to a decided conclusion. Is Mr. Stephenson to be the person upon whose faith this Committee is to pass this Bill involving property to the extent of £400,000/£500,000 when he is so ignorant of his profession as to propose to build a bridge not sufficient to carry off the flood water of the river or to permit any of the vessels to pass which of necessity must pass under it."

"I got leave to go from Killingworth to lay down a railway at Hetton, and next to Darlington, and after that I went to Liverpool to plan the line to Manchester. I there pledged myself to attain a speed of ten miles an hour. I said I had no doubt the engine would go much faster, but we had better be moderate at the beginning. The directors said I was quite right, for if when they came to Parliament I talked of going at a greater rate than ten miles an hour, I would put a cross on the concern. It was not an easy task for me to keep engines down to ten miles an hour, but it must be done, and did my best. I had to place myself in the most unpleasant of all situations, the witness-box of a Parliamentary Committee. Someone inquired if I was a foreigner, and another hinted that I was mad. Many became alarmed at this "Watt run wild," and in order to prevent these mad steam engines running beyond an old horse trot, they got two eminent engineers to act as Lunacy Commissioners. These gentlemen proved it was practically and commercially inexpedient. I put up with insult and rebuff, and went on with my plans, determined not to be put down. Improvements were made every day, and to-day a train has brought me from London in the morning and enabled me to take my place in this room."

"I was threatened to be ducked in the pond if I proceeded, and of course we had a great deal of the survey to take by stealth at the time when the persons were at dinner; we would not get it by night, for we were watched day and night and guns were discharged over the ground belonging to Captain Bradshaw to prevent us. I can state further, I was twice turned off the ground myself by his men; and they said if I did not go instantly they would carry me off to Worsley."