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.

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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 x 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.

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THE FLOW OF WATER THROUGH TURBINES AND SCREW PROPELLERS.

[Footnote:  Paper read before the British Association at Montreal.]

By Mr. Arthur Rigg, C.E.

Literature relating to turbines probably stands unrivaled among all that concerns questions of hydraulic engineering, not so much in its voluminous character as in the extent to which purely theoretical writers have ignored facts, or practical writers have relied upon empirical rules rather than upon any sound theory.  In relation to this view, it may suffice to note that theoretical deductions have frequently been based upon a generalization that “streams of water must enter the buckets of a turbine without shock, and leave them without velocity.”  Both these assumed conditions are misleading, and it is now well known that in every good turbine both are carefully disobeyed.  So-called practical writers, as a rule, fail to give much useful information, and their task seems rather in praise of one description of turbine above another.  But generally, it is of no consequence whatever how a stream of water may be led through the buckets of any form of turbine, so long as its velocity gradually becomes reduced to the smallest amount that will carry it freely clear of the machine.