an autobiography-第23章
按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
on were of that special class of workmen called millwrights a class now almost extinct； though many of the best known engineers originally belonged to them。 They could work with equal effectiveness in wood or iron。
Another foreman in Mr。 Patterson's foundry was called Lewis。 He had special charge of the iron castings designed for architectural and ornamental purposes。 He was a man of great taste and artistic feeling； and I was able even at that time to appreciate the beauty of his designs。 One of the most original characters about the foundry； however； was Johnie Syme。 He took charge of the old Boulton and Watt steam…engine； which gave motion to the machinery of the works。 It also produced the blast for the Cupolas； in which the pig and cast iron scrap was daily melted and cast into the various objects produced in the foundry。 Johnie was a complete incarnation of technical knowledge。 He was the Jack…of…all…trades of the establishment； and the standing counsel in every out…of…the…way case of managing and overcoming mechanical difficulties。 He was the superintendent of the boring machines。 In those days the boring of a steam…engine cylinder was considered high art in excelsis！ Patterson's firm was celebrated for the accuracy of its boring。
I owe Johnie Syme a special debt of gratitude； as it was he who first initiated me into that most important of all technical processes in practical mechanismthe art of hardening and temperinq steel。 It is； perhaps； not saying too much to assert that the successful practice of the mechanical arts； by means of which man rises from the savage to the civilised state； is due to that wonderful change。 Man began with wood； and stone； and bone； he proceeded to bronze and iron； but it was only by means of hardened steel that he could accomplish anything in arms； in agriculture； or in architecture。 The instant hardening which occurs on plunging a red…hot piece of steel into cold water may well be described as mysterious。 Even in these days； when science has defined the causes of so many phenomena； the reason of steel becoming hard on suddenly cooling it down from a red…heat； is a fact that no one has yet explained。 The steel may be tempered by modifying the degree of heat to which it is afterwards subjected。 It may thus be toughened by slightly reheating the hardened steel； the resoftening course is indicated by certain prismatic tints； which appear in a peculiar order of succession on its surface。 The skilful artisan thus knows by experience the exact point at which it is necessary again to plunge it into cold water in order to secure the requisite combination of toughness and hardness to the steel required for his purposes。
In all these matters； my early instructor； Johnie Syme； gave me such information as proved of the greatest use to me in the after progress of my mechanical career。 Johnie Syme was also the very incarnation of quaint sly humour； and when communicating some of his most valued arcana of practical mechanical knowledge he always reminded me of some of Ostade's Dutchmen； by an almost indescribable sly humorous twinkle of the eye； which in that droll way stamped his information on my memory。
Tom Smith was another of my attached cronies。 Our friendship began at the High School in 1818。 Our similarity of disposition bound us together。 Smith was the son of an enterprising general merchant at Leith。 His father had a special genius for practical chemistry。 He had established an extensive colour manufactory at Portobello； near Edinburgh； where he produced white lead； red lead； and a great variety of coloursin the preparation of which he required a thorough knowledge of chemistry。Tom Smith inherited his father's tastes； and admitted me to share in his experiments； which were carried on in a chemical laboratory situated behind his father's house at the bottom of Leith Walk。
We had a special means of communication。 When anything particular was going on at the laboratory； Tom hoisted a white flag on the top of a high pole in his father's garden。 Though I was more than a mile apart； I kept a look…out in the direction of the laboratory with a spy…glass。 My father's house was at the top of Leith Walk； and Smith's house was at the bottom of it。 When the flag was hoisted I could clearly see the invitation to me to 〃come down。〃 I was only too glad to run down the Walk and join my chum； and take part with him in some interesting chemical process。 Mr。 Smith； the father； made me heartily welcome。 He was pleased to see his son so much attached to me； and he perhaps believed that I was worthy of his friendship。 We took zealous part in all the chemical proceedings； and in that way Tom was fitting himself for the business of his life。
Mr。 Smith was a most genial tempered man。 He was shrewd and quick…witted； like a native of York； as he was。 I received the greatest kindness from him as well as from his family。 His house was like a museum。 It was full of cabinets； in which were placed choice and interesting objects in natural history； geology； mineralogy； and metallurgy。 All were represented。 Many of these specimens had been brought to him from abroad by his ship captains who transported his colour manufactures and other commodities to foreign parts。
My friend Tom Smith and I made it a ruleand in this we were encouraged by his fatherthat； so far as was possible； we ourselves should actually make the acids and other substances used in our experiments。 We were not to buy them ready made； as this would have taken the zest out of our enjoyment。 We should have lost the pleasure and instruction of producing them by aid of our own wits and energies。 To encounter and overcome a difficulty is the most interesting of all things。 Hence； though often baffled； we eventually produced perfect specimens of nitrous； nitric； and muriatic acids。 We distilled alcohol from duly fermented sugar and water； and rectified the resultant spirit from fusel oil by passing the alcoholic vapour through animal charcoal before it entered the worm of the still。 We converted part of the alcohol into sulphuric ether。 We produced phosphorus from bones； and elaborated many of the mysteries of chemistry。
The amount of practical information which we obtained by this system of making our own chemical agents was such as to reward us； in many respects； for the labour we underwent。 To outsiders it might appear a very troublesome and roundabout way of getting at the finally desired result。 But I feel certain that there is no better method of rooting chemical or any other instruction； deeply in our minds。 Indeed； I regret that the same system is not pursued by young men of the present day。 They are seldom； if ever； called upon to exert their own wits and industry to obtain the requisites for their instruction。 A great deal is now said about 〃technical education〃； but how little there is of technical handiness or head work！ Everything is bought ready made to their hands； and hence there is no call for individual ingenuity。
I often observe； in shop…windows； every detail of model ships and model steam…engines； supplied ready made for those who are 〃said to be〃 of an ingenious and mechanical turn。 Thus the vital uses of resourcefulness are done away with； and a sham exhibition of mechanical genius is paraded before you by the young impostorsthe result； for the most part； of too free a supply of pocket money。 I have known too many instances of parents； led by such false evidence of constructive skill； apprenticing their sons to some engineering firm； and； after paying vast sums； finding out that the pretender comes out of the engineering shop with no other practical accomplishment than that of cigar…smoking！
The truth is that the eyes and the fingersthe bare fingersare the two principal inlets to sound practical instruction。 They are the chief sources of trustworthy knowledge as to all the materials and operations which the engineer has to deal with； No book knowledge can avail for that purpose。 The nature and properties of the materials must come in through the finger ends。 Hence； I have no faith in young engineers who are addicted to wearing gloves。 Gloves； especially kid gloves； are perfect
