In "Wood on Railroads," second edition, 1832, page 377, we are told that "after those experiments"--the Rainhill trials--"were concluded, the Novelty underwent considerable alterations;" and on page 399, "Mr. Stephenson had also improved the working of the Rocket engine, and by applying the steam more powerfully in the chimney to increase the draught, was enabled to raise a much greater quantity of steam than before." Nothing is said as to where the new experiments took place, nor their precise date. But it seems that the Meteor and the Arrow--Stephenson engines--were tried at the same time; and this is really the only hint Wood gives as to what was done to the Rocket between the 6th of October, 1829, and the 15th of September, 1830. There are men still alive who no doubt could clear up the question at issue, and it is much to be hoped that they will do so. As the matter now stands, it will be seen that we do not so much question that the Rocket in South Kensington Museum is, in part perhaps, the original Rocket of Rainhill celebrity, as that it ever ran in regular service on the Liverpool and Manchester Railway. Yet, if not, then we may ask, what became of the Rocket of 1830? It is not at all improbable that the first Rocket was cast on one side, until it was bought by Lord Dundonald, and that its history is set out with fair accuracy above. But the Rocket of the Manchester and Liverpool Railway is hardly less worthy of attention than its immediate predecessor, and concerning it information is needed. Any scrap of information, however apparently trifling, that can be thrown on this subject by our readers will be highly valued, and given an appropriate place in our pages.--_The Engineer_. * * * * * The largest grain elevator in the world, says the _Nashville American_, is that just constructed at Newport News under the auspices of the Chesapeake & Ohio Railway Co. It is 90 ft. wide, 386 ft. long, and about 164 ft. high, with engine and boiler rooms 40 × 100 ft. and 40 ft. high. In its construction there were used about 3,000 piles, 100,000 ft. of white-oak timber, 82,000 cu. ft. of stone, 800,000 brick, 6,000,000 ft. of pine and spruce lumber, 4,500 kegs of nails, 6 large boilers, 2 large engines, 200 tons of machinery, 20 large hopper-scales, and 17,200 ft. of rubber belts, from 8 to 48 in. wide and 50 to 1,700 ft. long; in addition, there were 8,000 elevator buckets, and other material. The storage capacity is 1,600,000 bushels, with a receiving capacity of 30,000, and a shipping capacity of 20,000 bushels per hour. * * * * * THE FLOW OF WATER THROUGH TURBINES AND SCREW PROPELLERS. [Footnote: Paper read before the British Association at Montreal.] By Mr. ARTHUR RIGG, C.E.