liquid carbonic acid, or carbonic acid ice expanding again to a gas was employed as a motive power, another advance was made. Then the greatest lift of all was given. The solidification of oxygen and hydrogen by an easy process was discovered and mankind presented with a new motive power. In due time a way was found to make the solid substance re-assume the gaseous form either suddenly or by degrees, and thenceforth thousands of potential horse-power could be obtained in a form convenient for storing or carrying about. It is now as simple a matter to buy a hundred horse-power over the counter as a pound of sugar. From Toronto to Winnipeg in thirty minutes! From Winnipeg to the Pacific in forty minutes! Such is our usual pace in 1983. By hiring a special car the whole distance from Toronto to Victoria can be accomplished in fifty minutes. A higher speed still is quite possible, but is not permitted because of the risk of collision with other cars. Collisions have never yet occurred on account of the rigid adherence to very strict regulations. Cars that take short trips of 50 to 100 miles between stations, seldom travel more than 500 feet from the earth, but for long distances about 1,500 feet is usual. The broad metal slides for receiving the cars and for their departure, which extend for a mile on each side of all our stations, are the only portions of the rocket system which much resemble anything connected with railroads. It is said that great skill and long practice on the conductor's part are required to cause the cars to alight well on the slides and draw up at the stations. The slides at many stations are nearly level with the ground, but ascend in opposite directions, till at the distance of a mile, where they end, they are 100 feet high. The cars are now made quite cylindrical, tapering off abruptly at the closed end. The outside is entirely of metal, very highly polished, and showing no projections except a flange on each side, two broad runners underneath, and a 40 foot rear flange or vane. The dimensions are usually--diameter of cylinder, 20 feet; length, 45 feet. The high polish is necessary to avoid heating when the highest speed is attained. Passengers are seated in a luxurious chamber in the interior of the cylinder, which is suspended like the compass of a vessel, and therefore always retains an upright position whatever may be the position of the car when travelling. About fifty passengers can be accommodated at one time. The tube emerging a little beyond the mouth of the cylinder, through which the expanding gases are expelled, can be slightly deviated from its axial position in any direction, and thus what little steering is required is easily effected. The long projecting 40 foot vane or tail which steadies the motion of the whole machine is, in the newest patents, made to assist it in alighting on the slides easily and without jarring. Such is the splendid apparatus,