As remarked in a previous place, no one can expect to prepare successful designs for machinery5, who does not understand the details of its construction; he should know how each piece is moulded, forged, turned, planed, or bored, and the relative cost of these processes by the different methods which may be adopted.
An engineer may direct and control work without a knowledge of practical fitting, but such control is merely a commercial one, and cannot of course extend to mechanical details which are generally the vital part; the obedience7 that may thus be enforced in controlling others is not to be confounded with the respect which a superior knowledge of work commands.
A gain from learning practical fitting is the confidence which such knowledge inspires in either the direction of work or the preparation of plans for machinery. An engineer who hesitates in his plans for fear of criticism, or who does not feel a perfect confidence in them, will never achieve much success.
Improvements, which have totally changed machine fitting during thirty years past, have been of a character to dispense8 in a great measure with hand skill, and supplant9 it with what may be termed mental skill. The mere6 physical effect produced by a man's hands has steadily10 diminished in value, until it has now almost come to be reckoned in foot-pounds; but the necessity [166] for practical knowledge instead of being diminished is increased.
Formerly11 an apprentice12 entered a shop to learn hand skill, and to acquaint himself with a number of mysterious processes; to learn a series of arbitrary rules which might serve to place him at a disadvantage even with those whose capacity was inferior and who had less education; but now the whole is changed. An engineer apprentice enters the shop with a confidence that he may learn whatever the facilities afford if he will put forth13 the required efforts; there are no mysteries to be solved; nearly all problems are reached and explained by science, leaving a greater share of the shop-time of a learner to be devoted14 to studying what is special.
This change in engineering pursuits has also produced a change in the workmen almost as thorough as in manipulation. A man who deals with special knowledge only and feels that the secrets of his calling are not governed by systematic15 rules, by which others may qualify themselves without his assistance, is always more or less narrow-minded and ignorant. The nature of his relations to others makes him so; of this no better proof is wanted than to contrast the intelligence of workmen who are engaged in what may be termed exclusive callings with people whose pursuits are regulated by general rules and principles. A machinist of modern times, having outgrown16 this exclusive idea, has been raised thereby17 to a social position confessedly superior to that of most other mechanics, so that shop association once so dreaded18 by those who would otherwise have become mechanics, is no longer an obstacle.
Some hints will now be given relating to apprentice experience in a workshop, such matters being selected as are most likely to be of interest and use to a learner.
Upon entering a shop the first thing to be done is to gain the confidence and the respect of the manager or foreman who has charge of the work; to gain such confidence and respect is different from, and has nothing to do with, social relations and must depend wholly upon what transpires19 in the works. To inspire the confidence of a friend one must be kind, faithful, and honourable20; but to command the confidence of a foreman one must be punctual, diligent21, and intelligent. There are no more kindly22 sentiments than those which may be founded on a regard for industry and earnest effort. A learner may have the misfortune to break tools, spoil work, and fail in every [167] way to satisfy himself, yet if he is punctual, diligent, and manifests an interest in the work, his misfortunes will not cause unkind resentment.
It must always be remembered that what is to be learned should not be estimated according to a learner's ideas of its importance. A manager and workmen generally look upon fitting as one of the most honourable and intelligent of pursuits, deserving of the respect and best efforts of an apprentice; and while a learner may not think it a serious thing to make a bad fit, or to meet with an accident, his estimate is not the one to judge from. The least word or act which will lead workmen to think that an apprentice is indifferent, at once destroys interest in his success, and cuts off one of the main sources from which information may be derived23.
An apprentice in entering the workshop should avoid everything tending to an appearance of fastidiousness, either of manner or dress; nothing is more repulsive24 to workmen, and it may be added, nothing is more out of place in a machine shop than to divide one's time between the work and an attempt to keep clean. An effort to keep as neat as the nature of the work will admit is at all times right, but to dress in clothing not appropriate, or to allow a fear of grease to interfere25 with the performance of work, is sure to provoke derision.
The art of keeping reasonably clean even in a machine shop is worth studying; some men are greased from head to foot in a few hours, no matter what their work may be; while others will perform almost any kind of work, and keep clean without sacrificing convenience in the least. This difference is the result of habits readily acquired and easily retained.
Punctuality costs nothing, and buys a great deal; a learner who reaches the shop a quarter of an hour before starting time, and spends that time in looking about, manifests thereby an interest in the work, and avails himself of an important privilege, one of the most effectual in gaining shop knowledge. Ten minutes spent in walking about, noting the changes wrought26 in the work from day to day, furnishes constant material for thought, and acquaints a learner with many things which would otherwise escape attention. It requires, however, no little care and discrimination to avoid a kind of resentment which workmen feel in having their work examined, especially if they have met with an accident or made a mistake, and when such inspection27 is thought to be [168] prompted by curiosity only. The better plan in such cases is to ask permission to examine work in such a way that no one will hear the request except the person addressed; such an application generally will secure both consent and explanation.
Politeness is as indispensable to a learner in a machine shop as it is to a gentleman in society. The character of the courtesy may be modified to suit the circumstances and the person, but still it is courtesy. An apprentice may understand differential calculus28, but a workman may understand how to bore a steam cylinder29; and in the workman's estimation a problem in calculus is a trivial thing to understand compared with the boring of a steam engine cylinder. Under these circumstances, if a workman is not allowed to balance some of his knowledge against politeness, an apprentice is placed at a disadvantage.
Questions and answers constitute the principal medium for acquiring technical information, and engineering apprentices30 should carefully study the philosophy of questions and answers, just as he does the principles of machinery. Without the art of questioning but slow progress will be made in learning shop manipulation. A proper question is one which the person asked will understand, and the answer be understood when it is given; not an easy rule, but a correct one. The main point is to consider questions before they are asked; make them relevant to the work in hand, and not too many. To ask frequent questions, is to convey an impression that the answers are not considered, an inference which is certainly a fair one, if the questions relate to a subject demanding some consideration. If a man is asked one minute what diametrical pitch means, and the next minute how much cast iron shrinks in cooling, he is very apt to be disgusted, and think the second question not worth answering.
It is important, in asking questions, to consider the mood and present occupation of the person addressed; one question asked when a man's mind is not too much occupied, and when he is in a communicative humour, is worth a dozen questions asked when he is engaged, and not disposed to talk.
It is a matter of courtesy in the usages of a shop, and one of expediency31 to a learner, to ask questions from those who are presumed to be best informed on the subject to which the questions relate; and it is equally a matter of courtesy to ask questions of different workmen, being careful, however, never to ask two different persons the same question, nor questions that [169] may call out conflicting answers.
There is not a more generous or kindly feeling in the world than that with which a skilled mechanic will share his knowledge with those who have gained his esteem32, and who he thinks merit and desire the aid that he can give.
An excellent plan to retain what is learned, is to make notes. There is nothing will assist the memory more in learning mechanics than to write down facts as they are learned, even if such memoranda33 are never referred to after they are made.
It is not intended to recommend writing down rules or tables relating to shop manipulation so much as facts which require remark or comment to impress them on the memory; writing notes not only assists in committing the subjects to memory, but cultivates a power of composing technical descriptions, a very necessary part of an engineering education. Specifications34 for engineering work are a most difficult kind of composition and may be made long, tedious, and irrelevant35, or concise36 and lucid37.
There are also a large number of conventional phrases and endless technicalities to be learned, and to write them will assist in committing them to memory and decide their orthography38.
In making notes, as much as possible of what is written should be condensed into brief formul?, a form of expression which is fast becoming the written language of machine shops. Reading formul? is in a great degree a matter of habit, like studying mechanical drawings; that which at the beginning is a maze39 of complexity40, after a time becomes intelligible41 and clear at a glance.
Upon entering the shop, a learner will generally, to use a shop phrase, "be introduced to a hammer and chisel42;" he will, perhaps, regard these hand tools with a kind of contempt. Seeing other operations carried on by power, and the machines in charge of skilled men, he is likely to esteem chipping and filing as of but little importance and mainly intended for keeping apprentices employed. But long after, when a score of years has been added to his experience, the hammer, chisel, and file, will remain the most crucial test of his hand skill, and after learning to manipulate power tools of all kinds in the most thorough manner, a few blows with a chipping hammer, or a half-dozen strokes with a file, will not only be a more difficult test of skill, but one most likely to be met with.
[170]
To learn to chip and file is indispensable, if for no other purpose, to be able to judge of the proficiency43 of others or to instruct them. Chipping and filing are purely44 matters of hand skill, tedious to learn, but when once acquired, are never forgotten. The use of a file is an interesting problem to study, and one of no little intricacy; in filing across a surface one inch wide, with a file twelve inches long, the pressure required at each end to guide it level may change at each stroke from nothing to twenty pounds or more; the nice sense of feeling which determines this is a matter of habit acquired by long practice. It is a wonder indeed that true surfaces can be made with a file, or even that a file can be used at all, except for rough work.
If asked for advice as to the most important object for an apprentice to aim at in beginning his fitting course, nine out of ten experienced men will say, "to do work well." As power is measured by force and velocity45, work is measured by the two conditions of skill and time. The first consideration being, how well a thing may be done, and secondly46, in how short a time may it be performed; the skill spent on a piece of work is the measure of its worth; if work is badly executed, it makes no difference how short the time of performance has been; this can add nothing to the value of what is done although the expense is diminished.
A learner is apt to reverse this proposition at the beginning, and place time before skill, but if he will note what passes around him, it will be seen that criticism is always first directed to the character of work performed. A manager does not ask a workman how long a time was consumed in preparing a piece of work until its character has been passed upon; in short, the quality of work is its mechanical standard, and the time consumed in preparing work is its commercial standard. A job is never properly done when the workman who performed it can see faults, and in machine fitting, as a rule, the best skill that can be applied47 is no more than the conditions call for; so that the first thing to be learned is to perform work well, and afterwards to perform it rapidly.
Good fitting is often not so much a question of skill as of the standard which a workman has fixed48 in his mind, and to which all that he does will more or less conform. If this standard is one of exactness and precision, all that is performed, whether it be filing, turning, planing, or drawing, will come to this standard. This faculty49 of mind can be defined no further than to say that it is an aversion to whatever is imperfect, and a love for what [171] is exact and precise. There is no faculty which has so much to do with success in mechanical pursuits, nor is there any trait more susceptible50 of cultivation51. Methodical exactness, reasoning, and persistence52 are the powers which lead to proficiency in engineering pursuits.
There is, perhaps, no more fitting conclusion to these suggestions for apprentices than a word about health and strength. It was remarked in connection with the subject of drawing, that the powers of a mechanical engineer were to be measured by his education and mental abilities, no more than by his vitality53 and physical strength, a proposition which it will be well for an apprentice to keep in mind.
One not accustomed to manual labour will, after commencing, find his limbs aching, his hands sore; he will feel exhausted54 both at the beginning and at the end of a day's work. These are not dangerous symptoms. He has only to wait until his system is built up so as to sustain this new draught55 upon its resources, and until nature furnishes a power of endurance, which will in the end be a source of pride, and add a score of years to life. Have plenty of sleep, plenty of plain, substantial food, keep the skin clean and active, laugh at privations, and cultivate a spirit of self-sacrifice and a pride in endurance that will court the hardest and longest efforts. An apprentice who has not the spirit and firmness to endure physical labour, and adapt himself to the conditions of a workshop, should select some pursuit of a nature less aggressive than mechanical engineering.
The End
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1
superfluous
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| adj.过多的，过剩的，多余的 | |
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attain
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| vt.达到，获得，完成 | |
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resentment
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| n.怨愤，忿恨 | |
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possessed
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| adj.疯狂的；拥有的，占有的 | |
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machinery
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| n.(总称)机械，机器；机构 | |
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mere
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| adj.纯粹的；仅仅，只不过 | |
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obedience
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| n.服从，顺从 | |
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dispense
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| vt.分配，分发；配(药)，发(药)；实施 | |
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supplant
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| vt.排挤；取代 | |
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steadily
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| adv.稳定地；不变地；持续地 | |
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formerly
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| adv.从前，以前 | |
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apprentice
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| n.学徒，徒弟 | |
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forth
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| adv.向前；向外，往外 | |
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devoted
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| adj.忠诚的，忠实的，热心的，献身于...的 | |
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systematic
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| adj.有系统的，有计划的，有方法的 | |
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outgrown
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| 长[发展] 得超过（某物）的范围( outgrow的过去分词 )； 长[发展]得不能再要（某物）； 长得比…快； 生长速度超过 | |
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thereby
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| adv.因此，从而 | |
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dreaded
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| adj.令人畏惧的；害怕的v.害怕，恐惧，担心( dread的过去式和过去分词) | |
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transpires
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| （事实，秘密等）被人知道( transpire的第三人称单数 )； 泄露； 显露； 发生 | |
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honourable
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| adj.可敬的；荣誉的，光荣的 | |
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diligent
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| adj.勤勉的，勤奋的 | |
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kindly
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| adj.和蔼的，温和的，爽快的；adv.温和地，亲切地 | |
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derived
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| vi.起源；由来；衍生；导出v.得到( derive的过去式和过去分词 )；（从…中）得到获得；源于；（从…中）提取 | |
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repulsive
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| adj.排斥的，使人反感的 | |
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interfere
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| v.(in)干涉，干预；(with)妨碍，打扰 | |
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wrought
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| v.引起；以…原料制作；运转；adj.制造的 | |
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inspection
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| n.检查，审查，检阅 | |
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calculus
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| n.微积分；结石 | |
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cylinder
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| n.圆筒，柱(面)，汽缸 | |
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apprentices
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| 学徒，徒弟( apprentice的名词复数 ) | |
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expediency
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| n.适宜；方便；合算；利己 | |
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esteem
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| n.尊敬，尊重；vt.尊重，敬重；把…看作 | |
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memoranda
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| n. 备忘录, 便条 名词memorandum的复数形式 | |
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specifications
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| n.规格；载明；详述；（产品等的）说明书；说明书( specification的名词复数 )；详细的计划书；载明；详述 | |
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irrelevant
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| adj.不恰当的，无关系的，不相干的 | |
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concise
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| adj.简洁的，简明的 | |
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lucid
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| adj.明白易懂的，清晰的，头脑清楚的 | |
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orthography
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| n.拼字法，拼字式 | |
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maze
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| n.迷宫，八阵图，混乱，迷惑 | |
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complexity
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| n.复杂(性)，复杂的事物 | |
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intelligible
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| adj.可理解的，明白易懂的，清楚的 | |
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chisel
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| n.凿子；v.用凿子刻，雕，凿 | |
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proficiency
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| n.精通，熟练，精练 | |
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purely
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| adv.纯粹地，完全地 | |
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velocity
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| n.速度，速率 | |
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secondly
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| adv.第二，其次 | |
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applied
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| adj.应用的；v.应用，适用 | |
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fixed
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| adj.固定的，不变的，准备好的；(计算机)固定的 | |
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faculty
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| n.才能；学院，系；(学院或系的)全体教学人员 | |
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susceptible
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| adj.过敏的，敏感的；易动感情的，易受感动的 | |
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51
cultivation
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| n.耕作，培养，栽培（法），养成 | |
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persistence
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| n.坚持，持续，存留 | |
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vitality
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| n.活力，生命力，效力 | |
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exhausted
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| adj.极其疲惫的，精疲力尽的 | |
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draught
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| n.拉，牵引，拖；一网（饮，吸，阵)；顿服药量，通风；v.起草，设计 | |
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