The Brooklyn Eagle gives a very interesting description of the three new steamships now almost completed and shortly to be placed in the New York and Liverpool trade by the Cunard, Inman, and Williams and Guion lines. The writer has prepared a table comparing the three vessels with each other and with the Great Eastern, the only ship of greater dimensions ever built. We give as much of the article as our space will allow, and regret that we have not the room to give it entire:

 Line. Cunard. Inman. Guion. Admiralty.

Vessel. Servia City of Rome. Alaska. Great[1] 
Length 530 feet. 546 feet. 520 feet. 679 feet. Breadth 52 feet. 52 ft. 3 in. 50 ft. 6 in. 82 feet. Depth 44 ft. 9 in. 37 feet. 38 feet. 60 feet. Gross ton'ge 8,500 8,300 8,000 13,344[2] Horse pow'r 10,500 10,000 11,000 2,600 Speed 17½ knots. 18 knots. 18 knots. 14 knots. Sal'n pas- 320 and 52 sengers. 450 300 2d class Steerage 600 1,500 1,000 Where Clydeb'nk Barrow in Clyde, built. Thomson Furness Elder Date of sailing. October 22 October 13 November 5

[Footnote 1: To be sold at auction soon.]

[Footnote 2: Net register.]

In 1870 the total tonnage of British steam shipping was 1,111,375; the returns for the year 1876 showed an increase to 2,150,302 tons, and from that time to the present it has been increasing still more rapidly. But, as can be seen from the above table, not only has the total tonnage increased to this enormous extent, but an immense advance has been made in increasing the size of vessels. The reason for this is, that it has been found that where speed is required, along with large cargo and passenger accommodation, a vessel of large dimensions is necessary, and will give what is required with the least proportionate first cost as well as working cost. Up to the present time the Inman line possessed, in the City of Berlin, of 5,491 tons, the vessel of largest tonnage in existence. Now, however, the Berlin is surpassed by the City of Rome by nearly 3,000 tons, and the latter is less, by 200 tons, than the Servia, of the Cunard line. It will be observed, too, that while there is not much difference between the three vessels in point of length, the depth of the Alaska and the City of Rome, respectively, is only 38 feet and 37 feet, that of the Servia is nearly 45 feet as compared with that of the Great Eastern of 60 feet. This makes the Servia, proportionately, the deepest ship of all. All three vessels are built of steel. This metal was chosen not only because of its greater strength as against iron, but also because it is more ductile and the advantage of less weight is gained, as will be seen when it is mentioned that the Servia, if built of iron, would have weighed 620 tons more than she does of steel, and would have entailed the drawback of a corresponding increase in draught of water. As regards rig, the three vessels have each a different style. The Cunard Company have adhered to their special rig--three masts, bark rigged--believing it to be more ship shape than the practice of fitting up masts according to the length of the ship. On these masts there is a good spread of canvas to assist in propelling the ship. The City of Rome is rigged with four masts; and here the handsome full-ship rig of the Inman line has been adhered to, with the addition of the fore and aft rigged jigger mast, rendered necessary by the enormous length of the vessel. It will be seen that the distinctive type of the Inman line has not been departed from in respect to the old fashioned but still handsome profile, with clipper bow, figurehead, and bowsprit--which latter makes the Rome's length over all 600 feet. For the figurehead has been chosen a full length figure of one of the Roman Cæsars, in the imperial purple. Altogether, the City of Rome is the most imposing and beautiful sight that can be seen on the water. The Alaska has also four masts, but only two crossed.

The length of the City of Rome, as compared with breadth, insures long and easy lines for the high speed required; and the depth of hold being only 37 feet, as compared with the beam of 52 feet, insures great stability and the consequent comfort of the passengers. A point calling for special notice is the large number of separate compartments formed by water tight bulkheads, each extending to the main deck. The largest of these compartments is only about 60 feet long; and, supposing that from collision or some other cause, one of these was filled with water, the trim of the vessel would not be materially affected. With a view to giving still further safety in the event of collision or stranding, the boilers are arranged in two boiler rooms, entirely separated from each other by means of a water tight iron bulkhead. This reduces what, in nearly all full-powered steamships, is a vast single compartment, into two of moderate size, 60 feet in length; and in the event of either boiler room being flooded, it still leaves the vessel with half her boiler power available, giving a speed of from thirteen to fourteen knots per hour. The vessel's decks are of iron, covered with teak planking; while the whole of the deck houses, with turtle decks and other erections on the upper deck, are of iron, to stand the strains of an Atlantic winter. Steam is supplied by eight cylindrical tubular boilers, fired from both ends, each of the boilers being 19 feet long and having 14 feet mean diameter. There are in all forty eight furnaces. The internal arrangements are of the finest description. There are two smoking rooms, and in the after deckhouse is a deck saloon for ladies, which is fitted up in the most elegant manner, and will prevent the necessity of going below in showery weather. At the sides of the hurricane deck are carried twelve life boats, one of which is fitted as a steam launch. The upper saloon or drawing-room is 100 feet long, the height between decks being 9 feet. The grand dining-saloon is 52 feet long, 52 feet wide, and 9 feet high, or 17 feet in the way of the large opening to the drawing-room above. This opening is surmounted by a skylight, and forms a very effective and elegant relief to the otherwise flat and heavy ceiling. There are three large and fourteen small dining tables, the large tables being arranged longitudinally in the central part of the saloon, and the small tables at right angles on the sides. Each diner has his own revolving arm chair, and accommodation is provided for 250 persons at once. A large American organ is fixed at the fore end of the room, and opening off through double spring doors at the foot of the grand staircase is a handsome American luncheon bar, with the usual fittings. On each side of the vessel, from the saloon to the after end of the engine room, are placed staterooms providing for 300 passengers. The arrangements for steerage passengers are of a superior description. The berths are arranged in single tiers or half rooms, not double, as is usually the custom, each being separated by a passage, and having a large side light, thus adding greatly to the light, ventilation, and comfort of the steerage passengers, and necessitating the advantage of a smaller number of persons in each room. The City of Rome is the first of the two due here; she sails from Liverpool on October 13.

In the Servia the machinery consists of three cylinder compound surface condensing engines, one cylinder being 72 inches, and two 100 inches in diameter, with a stroke of piston of 6 feet 6 inches. There are seven boilers and thirty-nine furnaces. Practically the Servia is a five decker, as she is built with four decks--of steel, covered with yellow pine--and a promenade reserved for passengers. There is a music room on the upper deck, which is 50 feet by 22 feet, and which is handsomely fitted up with polished wood panelings. For the convenience of the passengers there are no less than four different entrances from the upper deck to the cabins. The saloon is 74 feet by 49 feet, with sitting accommodations for 350 persons, while the clear height under the beams is 8 feet 6 inches. The sides are all in fancy woods, with beautifully polished inlaid panels, and all the upholstery of the saloon is of morocco leather. For two-thirds of its entire length the lower deck is fitted up with first class staterooms. The ship is divided into nine water-tight bulkheads, and she is built according to the Admiralty requirements for war purposes. There are in all twelve boats equipped as life-boats. The Servia possesses a peculiarity which will add to her safety, namely, a double bottom, or inner skin. Thus, were she to ground on rocks, she would be perfectly safe, so long as the inner skin remained intact. Steam is used for heating the cabins and saloons, and by this means the temperature can be properly adjusted in all weathers. In every part of the vessel the most advanced scientific improvements have been adopted. The Servia leaves Liverpool on October 22.

The Alaska, whose owners, it is understood, are determined to make her beat all afloat in speed, does not sail until November 5, and therefore it is premature to say anything about her interior equipments. She is the sister of the celebrated Arizona, and was built by the well-known firm of Elder & Co., on the Clyde.