to obtain with portable wrought-iron structures and live loads. The
result in the present case is probably greatly due to the careful
workmanship, and to the fact that the sides and ends of the plates are
planed throughout, so that the webs of the girders get a fair bearing
on the top and bottom plates.

The crane showed itself to be very handy and quick in working, the
speeds with 19 tons load, as actually timed at the trial, are: lifting
16 ft. per minute, racking motion 46 ft. per minute, slewing through a
complete circle 90 ft. diameter, four minutes, equivalent to a speed
at load of 60 ft. per minute. The crane was constructed by Messrs.
Stothert & Pitt, of Bath, to the order of the Crown agents for the
colonies, and we understand that the design and construction have
given complete satisfaction to Sir J. Coode, the engineer to the
harbor works, under whose supervision the crane was
constructed.--_Engineering._

* * * * *




IMPROVED STEAM-BOILER.


An improvement in steam-boilers, best understood by reference to the
ordinary vertical form, has been introduced by Mr. T. Moy, London.
Here the flue is central, and, as shown in the accompanying
illustration, is crossed by a number of horizontal water-tubes at
different heights. The ends of these tubes are embraced, within the