the country; to the future is left further progress and improvements.

A single line of rails nailed down to transverse logs, and a train at rare intervals, are deemed to be sufficient as a commencement, and as traffic increases, additional improvements can be made.

65. Railway Crossings.-Bridges are seldom thought necessary to carry the common highways across the railroads where they intersect, gates are even in many cases dispensed with, and a notice of "Look out for the locomotive when the bell rings," is considered a sufficient warning, and wayfarers are left to take care of themselves. Sharp curves and steep inclines are frequently submitted to for the sake of economy.

66. Railroad Inclines.--The railroad that connects the eastern and western parts of Pennsylvania, bringing the towns on Lake Erie and the great western rivers into direct communication with Philadelphia and the Atlantic, consists at present of a single line of rails carried over the lofty ridges of the Alleghany Mountains by a series of inclined planes.

These are five in number, and the summit of the highest is 2,600 feet above the level of the The trains are dragged up each incline by

sea.

a rope attached to a drum worked by a stationary engine.

They are drawn across the plateaux which intervene between the inclines, in some cases by horses, in others by small locomotives. A new road is, however, being constructed which will cross the mountains by one long winding incline. The ascent will be so gradual in its circuitous course, that a locomotive will be able to ascend and descend with its train of carriages.

It is calculated that four hours will be saved by the substitution of this new route, and the dispensing with the stationary engines.

It is doubtful whether the delay would not have been very considerable, had the construction of the railroad been postponed until means had been found for executing these great works in the first instance.

67. Street Railroads.-It is a common practice to detach the carriages from the engine at the outskirts of towns, and draw them by horses along rails laid down in the streets.

Many objections may be made to this system, and it seems, on the whole, disadvantageous; a circuit of rails carried round the town would be more preferable.

68. Railroad Cars.-The construction of the

railroad cars or carriages commonly used in the United States has been frequently described.

They are very long, and are supported at each end on four-wheeled trucks, on which they swivel when turning the sharp curves, which are of ordinary occurrence.

A car constructed for sixty passengers measured 40 feet long, 84 feet wide, and 64 feet high, inside measure; small benches with reversible backs, having each two seats, are ranged parallel to each other down both sides of the carriage, leaving a passage clear from the door at one end to that of the other. The car afforded upwards of 2,200 cubic feet of space, or 37 feet per passenger. Its weight was 11 tons, giving a dead weight of about 3 cwt. per passenger.

The cost of a 60-passenger car is about $2,000 (4007.).

A contrivance has been lately tried for excluding the dust by connecting the different carriages together by indiarubber curtains at the ends, the air being admitted through the roof of the first carriage.

The object sought to be obtained is, a current of air running through the entire train, and always setting outwards from the interior of the carriages. The results did not appear to answer fully the expectation which had been formed

69. A Four-masted Clipper Ship.-A large clipper ship of 4,000 tons was being built at Boston; the length of keel was 287 feet, length on deck 320 feet, extreme breadth of beam 52 feet, and depth of hold 30 feet. Her keel is of rock maple in two thicknesses, the frame is of seasoned white oak, dowelled, and bolted together through the dowelling with 1 inch iron. The frame inside is diagonally crossbraced with iron, the braces being 4 inches wide, and 3 inch thick, bolted through every timber: these braces extend from the floor-heads to the top timbers, and form a perfect network of iron over all her frames fore and aft.

She has five depths of midship keelsons, each 16 inches square, three tier of sister keelsons, 15 inches square, bolted vertically and horizontally. There are four tiers of bilge keelsons on each side, 15 inches square. Ceiling, from bilge to lower deck 15 inches, scarped and bolted edgewise.

She has three full decks, securely fastened with fore and aft knees; the hanging knees are extra fastened, having in the lower hanging knees 18 bolts, 1 inch iron; middle deck, 20 bolts; also upper deck hanging knees, 20 bolts, and all of oak. Beams in lower deck, 14 by 16; in middle deck, 15 by 17; in upper deck, 12 by 16, and some 12 by 20 inches.

Lower deck main hatch is 14 by 20; middle deck, 14 by 16; and main deck 14 by 11.

She has a hurricane deck over all, merely for working the ship, thereby obviating the difficulty in obstructions from houses, spare spars, water casks, &c.

Her mainmast is 126 feet long, 98 above deck, diameter 44 inches; masts made of hard pine, to carry two stationary yards with trusses, the same as used on lower yards; fore and main deck alike, and those on the mizenmast the same as those on the other masts above the lower yards, so that, except the courses, all her sails will have duplicates on every yard fore and aft. Her main yard is 110 feet long, the others in proportion; she will have a fourth mast, principally to lead the mizen braces, to prevent the difficulty arising from mizen braces leading forward, and hauling the mast out of place.

The model of the ship was said to promise a combination of swiftness, buoyancy, and beauty that has never been excelled. Notwithstanding her vast size, such is her length and buoyancy that, when loaded ready for sea, her draught of water will not exceed 23 feet, a common draught for ships half her size.

70. Fire Companies.-The fire companies are formed in many towns of volunteers, who do