At Waltham Abbey, not half an hour's walk from Enfield Lock, is situated the only establishment for the manufacture of powder which the Government possesses. Here dispersion, instead of concentration, is the order of the day. The necessity for complete isolation causes the factories to be distributed over a very large space of ground, and the visitor has to walk from workshop to workshop through groves and avenues of willow and alder, as though he were visiting dispersed farm-buildings rather than the different departments of the same manufacturing process. There are not perhaps more than a dozen detached buildings in the whole establishment, yet these are scattered over upwards of fifty acres of ground. To such an extent do meadows and woods and meandering canals predominate, that the idea of being in a powder-mill is entirely lost in the impression that you are walking in a Dutch landscape. The visitor who enters the great gates of the mill, impressed with a belief in the dangerous nature of the ground he is treading, is somewhat startled on finding a steam-engine at work on the very threshold of the factory, and a tall chimney smoking its pipe in what he supposed to be the vicinity of hundreds of barrels of gunpowder; but in reality these boilers and furnaces are placed many hundred feet from the mixing-houses. The English Government powder is composed of seventy-five parts of saltpetre, fifteen parts of charcoal, and ten of sulphur. The ingredients, being thoroughly powdered, prepared, and purified, are submitted to the action of a machine, which completely mixes them. The product is then conveyed by a covered boat, very much like an aldermanic gondola in mourning, some hundred yards along the canal to the incorporating houses, where the most important process of the manufacture is carried on, and where the danger of an explosion first commences. The incorporating machine is nothing more than a couple of runners or huge wheels, weighing four and a half tons each, which revolve one after another on their edges in a bed of metal supplied with a deep wooden rim, which gives it much the appearance of a huge kitchen candlestick. Into this dish the black powder is placed, together with a little water, which varies in quantity, from four pints in winter, when the atmosphere is charged with moisture, to ten in the summer, when the desiccating quality of the air is very great. For four hours this pasty mass is crushed, ground, and mixed by the action of the runners. The precautions taken against explosion teach the visitor the dangerous nature of the ground he is treading. Before he puts his feet across the threshold he must encase them in leathern boots huge enough to fit Polyphemus, and guiltless of iron in any form whatever; even his umbrella or stick is snatched from him, lest the ferrule should strike fire, or accidentally drop among any part of the machinery whilst at work. The machinery is even protected against itself. In order to avoid the possibility of the linch-pins which confine the cylinders to their axles falling down, and by the action of "skidding" the runner, producing so much friction as to cause an explosion, receptacles are formed to catch them in their fall. As small pieces of grit, the natural enemy of the powder-maker, might prove dangerous if mixed with any of the "charges," the axle sockets of nearly all the wheels are constructed to expand, so as to allow any hard foreign body to pass through just in the same manner in which the fine jaws of the larger serpents are loosely hinged, to enable them to get over at one gulp such a bulky morsel as a full-grown rabbit.