The drawing-office is the brain of the factory. Within its walls new ideas are being put into practical shape by skilled draughtsmen. The drawings are sent to the model-making shop, where the parts are first fashioned in wood. The shop contains dozens of big benches, circular saws, and planing machines, one of them in the form of a revolving drum carrying a number of planes, which turns thousands of times a minute, and shapes off the rough surface of the blocks of hard wood as if it were so much clay. These blocks are cut, planed, and turned, and then put into the hands of a remarkably skilled class of workmen, who, with rule, calliper, and chisel, shape out cylinders and other parts to the drawings before them with wonderful patience and exactness.
After the model has been fashioned, the next step is to make a clay mould from the same, with a hole in the top through which the molten metal is poured. The foundry is most picturesque in a lurid, Rembrandtesque fashion: "It is black everywhere. The floor, walls, and roof are black, and the foundry hands look like unwashed penitents in sackcloth and ashes. At the end of the building there is a raised brickwork, and when the visitor is able to see in the darkness, he distinguishes a number of raised lids along the top, while here and there are strewn about huge iron ladles like buckets. On the foreman giving the word, a man steps up on the brickwork and removes the lid, when a column of intense white light strikes upwards. It gives one the impression of coming from the bowels of the earth, like a hole opening out in a volcano. The man bestrides the aperture, down which he drops the ladle at the end of a long pole, and then pulling it up again full of a straw-coloured, shining liquid, so close to him that we shudder at the idea of its spilling over his legs and feet, he pours the molten metal into a big ladle, which is seized by two men who pour the liquid into the moulds. The work is more difficult than it looks, for it requires a lot of practice to fill the moulds in such a way as to avoid blow-holes and flaws that prove such a serious item in foundry practice."
In the case-hardening department, next door, there are six huge ovens with sliding fronts. Therein are set parts which have been forged or machined, and are subjected to a high temperature while covered in charcoal, so that the skin of the metal may absorb carbon at high temperatures and become extremely tough. All shafts, gears, and other moving parts of a car are subjected to this treatment, which permits a considerable reduction in the weight of metal used, and greatly increases its resistance to wear. After being "carbonised," the material is tempered by immersion in water while of a certain heat, judged by the colour of the hot metal.
We now pass to the turning-shop, where the cylinders are bored out by a grinding disc rapidly rotating on an eccentric shaft, which is gradually advanced through the cylinder as it revolves. The utmost accuracy, to the 1/10,000 part of an inch, is necessary in this operation, since the bore must be perfectly cylindrical, and also of a standard size, so that any standard piston may exactly fit it. After being bored, or rather ground, the walls of the cylinder are highly polished, and the article is ready for testing. The workman entrusted with this task hermetically closes the ends by inserting the cylinder between the plates of an hydraulic press, and pumps in water to a required pressure. If there be the slightest crack, crevice, or hole, the water finds its way through, and the piece is condemned to the rubbish heap.
In the "motor-room" are scores of cylinders, crank-cases, and gears ready for finishing. Here the outside of bored cylinders is touched up by files to remove any marks and rough projections left by the moulds. The crank-cases of aluminium are taken in hand by men who chisel the edges where the two halves fit, chipping off the metal with wonderful skill and precision. The edges are then ground smooth, and after the halves have been accurately fitted, the holes for the bolts connecting them are drilled in a special machine, which presents a drill to each hole in succession.
Having seen the various operations which a cylinder has to go through, we pass into another shop given up to long lines of benches where various motor parts are being completed. Each piece, however small, is treated as of the utmost importance, since the failure of even a tiny pin may bring the largest car to a standstill. We see a man testing pump discs against a standard template to prove their absolute accuracy. Close by, another man is finishing a fly-wheel, chipping off specks of metal to make the balance true. We now understand that machine tools cannot utterly displace the human hand and eye. The fitters, with touches of the file, remove matter in such minute quantities that its removal might seem of no consequence. But "matter in the wrong place" is the cause of many breakdowns.
We should naturally expect that engines cast from the same pattern, handled by the same machines, finished by the same men, would give identical results. But as two bicycles of similar make will run differently, so do engines of one type develop peculiarities. The motors are therefore taken into a testing-room and bolted to two rows of benches, forty at a time. Here they run under power for long periods, creating a deafening uproar, until all parts work "sweetly." The power of the engines is tested by harnessing them to dynamos and noting the amount of current developed at a certain speed.
We might linger in the departments where accumulators, sparking plugs, and other parts of the electrical apparatus of a car are made, or in the laboratory where chemists pry into the results of a new alloy, aided by powerful microscopes and marvellously delicate scales. But we will stop only to note the powerful machine which is stretching and crushing metal to ascertain its toughness. No care in experimenting is spared. The chemist, poring over his test tubes, plays as important a part in the construction of a car as the foundry man or the turner.
The machine-shop is an object-lesson among the tools noticed in previous chapters of this book. "Here is a huge planing machine travelling to and fro over a copper bar. A crank shaft has been cut out of solid steel by boring holes close together through a thick plate, and the two sides of the plate have been broken off, leaving the rough shaft with its edges composed of a considerable number of semicircles. The shaft is slowly rotated on a lathe, and tiny clouds of smoke arise as the tool nicks off pieces of metal to reduce the shaft to a circular shape. Other machines, with high-speed tool steel, are finishing gear shafts. Fly-wheels are being turned and worm shafts cut. All these laborious operations are carried out by the machines, each under the control of one man whose mind is intent upon the work, ready to stop the machine or adjust the material as may be required. As a contrast to the heavy machines we will pass to the light automatic tools which are grouped in a gallery.... The eye is bewildered by the moving mass, but the whirling of the pulley shafts and the clicking of the capstan lathes is soothing to the ear, while the mind is greatly impressed by the ingenuity of man in suppressing labour by means of machines, of which half a dozen can be easily looked after by one hand, who has nothing to do but to see that they are fed with material. A rod of steel is put into the machine, and the turret, with half a dozen different tools, presents first one and then the other to the end of the rod bathed in thick oil, so that it is rapidly turned, bored, and shaped into caps, nuts, bolts, and the scores of other little accessories required in fitting up a motor-car. On seeing how all this work is done mechanically and methodically, with scarcely any other expense but the capital required in the upkeep of the machines and in driving them, one wonders how the automobile industry could be carried on without this labour-saving mechanism. In any event, if all these little pieces had to be turned out by hand, it is certain that the cost of the motor-car would be considerably more than it is, even if it did not reach to such a figure as to make it prohibitive to all but wealthy buyers. Down one side of the gallery the machines are engaged in cutting gears with so much precision that, when tested by turning them together on pins on a bench at the end of the gallery, it is very rare indeed that any one of them is found defective. This installation of automatic tools is one of the largest of its kind in a motor-car works, if not in any engineering shop, and each one has been carefully selected in view of its efficiency for particular classes of work, so that we see machines from America, England, France, and Germany."