William John Macquorn Rankine: Practice

“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.”

William John Macquorn Rankine

"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)
Context: 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.<!--p. 177

“The evil influence of the supposed inconsistency of theory and practice upon speculative science”

William John Macquorn Rankine

"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)
Context: 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.<!--pp. 175

Science , Evil

“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”

William John Macquorn Rankine

"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)
Context: 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.<!--p. 176

Knowledge , Evil , Personality

“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.”

William John Macquorn Rankine

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Men , Nature , Knowledge , Sense

“[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.”

William John Macquorn Rankine

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Money , Evil , Parting

“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.”

William John Macquorn Rankine

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Men , Knowledge , Science , Evil

“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.”

William John Macquorn Rankine

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Truth , Mathematics , Study , Science

“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.”

William John Macquorn Rankine

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Error

“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.”

William John Macquorn Rankine

"Introductory Lecture on the Harmony of Theory and Practice in Mechanics" (1856), p. 4

Men , Science

“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.”

William John Macquorn Rankine

p, 125
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Question , Sense , Science , Waiting

“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.”

William John Macquorn Rankine

"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Knowledge , Understanding , Relation ships

“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.”

William John Macquorn Rankine

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.
"On the Harmony of Theory and Practice in Mechanics" (Jan. 3, 1856)

Time , Evil