[Illustration: WHEELOCK'S AUTOMATIC CUT-OFF STEAM-ENGINE.]
The Belgium system of sinking shafts for mines and wells, invented by Kind and Chaudron, exhibited here as in Philadelphia, attracts great attention from its gigantic proportions. Imagine an immense boring-chisel (_trepan_), weighing 26,000 pounds and with a breadth of over six feet, worked up and down by machinery, the steel studs on its face stamping the rocks into dust, so that they can be removed with a bucket with bottom valves which is dropped into the hole and is worked up and down until the detritus and water, if any, creep into it, when it is withdrawn and emptied. The repetition of these processes makes the shaft of two mètres diameter. Then comes the larger trepan, with a width of 4.80 mètres, and repeats the process on a larger scale. This enormous chisel weighs 44,000 pounds. The system is much in favor, and forty-five shafts have been thus sunk between 1854 and 1877 in Belgium, France, England and Germany. Cast-iron lining is lowered in sections as the shaft deepens, the sections being added at the top and bolted together.
The Belgian exhibit contains also one of those immense paper-machines invented by the brothers Fourdrinier about fifty years ago, and now used almost universally for the best class of machine-made papers. They are used by Wilcox at Glen Falls, Delaware county, Penn., in making the government note and bond paper, and are a marvel of art. The Frenchmen who invented the machine brought it into use in England, but they were much hampered and discouraged by difficulties, and it was never a pecuniary success to them. It was a legacy to the future, and they have joined the army of martyrs to mechanical science. The machine in the Belgian section is one hundred and thirty feet long, and the Swiss machine, near by, is nearly as large. The French, with their customary ingenuity, have reduced the proportions very considerably. The Swiss machine makes paper one mètre and a half wide.
The remainder of the Belgian exhibit of machinery may be summarized: rock drills on the principle of those used at Mont Cenis; the gas-engines of Otto; machine tools, lathes, drills and planers; a very curious machine for cutting bevel or straight gears, built by a firm at Liège, and worthy of attention by Mr. Sellers or Mr. Corliss, whose ingenious machines for the same purpose were at Philadelphia; the woollen machinery of Celestine Martin of Verviers, which I recollect to have seen in Philadelphia also; multitubular boilers, rudder propeller, and hand fire-engines Then we see a number of locomotives and tramway engines, rail and street cars, winding, mining, crane and portable engines, and a full set of vacuum-pans for sugar, with engines, centrifugal filters and hydraulic presses. A glance at Guibal's great mine-ventilator fan, fifty feet in diameter and with ten wooden vanes, and we may quit the section of Belgium, which is the next largest after England of all the foreign departments here.