SCIENTIFIC SUMMARY. 
263 
horizontal direct-acting engines now so largely introduced. Hence there 
is no reason why the old-fashioned speed of 250 feet should be adhered to, 
and in the case of locomotives where necessity has compelled the change, 
speeds of 500 to 1,000 feet per minute are attained without difficulty. 
The little horizontal engine of Mr. Allen, in the Exhibition, worked 
regularly and with great steadiness at a piston speed of 600 feet per 
minute, doing twice the amount of work which it could have accomplished 
at the speed usual in this country. There is now no doubt that the 
direction of improvement which will be taken will be the adoption of a 
high speed and higher pressure than hitherto, with an enormous saving in 
the weight of the engines necessary for any given amount of work. 
Steel Vessels . — Two ocean vessels of large size have been launched 
at Liverpool, built entirely of steel, which had indeed been used before, 
but tentatively, and in smaller ships. In the case of the Formby , of 
1,276 tons burden, 300 tons of dead weight were saved out of 800 tons 
(which would have been necessary had she been built of iron), in conse- 
quence of the greater tenacity of the new material. 
Glass Bearings . — Glass bushes or steps are being used for bearings for 
shafts, by Mr. Burton, the glass being protected at the ends by metal 
flanges attached to the pedestal, with papier-mache or india-rubber 
interposed. 
Forging by Pressure . — Attempts are being made by Mr. Haswell, the 
Manager of the Austrian State Railways, and by Messrs. Shanks, E. B. 
Wilson, and Bessemer, to substitute hydraulic pressure for the blows of 
hammers, in forging masses of wrought iron and steel. The first-named 
has a press at work capable of exerting a pressure of 600 tons, by means 
of -which he has been enabled to forge a piston and rod in one piece at a 
single stroke. 
Clifton Suspension Bridge . — Our readers will be aw r are that the old 
Hungerford Suspension Bridge, having been taken down and replaced by 
Mr. Hawkshaw’s fine lattice railway bridge, is being re-erected at Clifton, 
near Bristol. For this purpose an ingenious temporary scaffolding has 
been contrived, on wffiich the links of the chain are to be put together. 
In the position to be occupied by one of the chains, six wires have been 
stretched across from pier to pier, and above these two other wires from 
which a light cradle is suspended. In this cradle the men were enabled to 
attach to the lower wires a platform of boards joined to the upper wires 
by hoop iron forming a railing. Fourteen feet above the platform another 
wire is stretched across, on which runs a traverser, furnished with blocks, 
by which the links of the chain are carried out to the men at work on the 
platform. In this way the great natural difficulties of the situation will 
be successfully overcome. The bridge will be 702 feet span, and 280 feet 
above low r water. 
Bhore Ghaut Incline. —The incline up the Bhore Ghaut range, recently 
completed, is one of the most remarkable achievements of Indian 
railway engineering. It is nearly 16 miles long, with a total rise of 1,831 
feet, the steepest gradients being- 1 in 37 and 1 in 40. It includes 25 tunnels 
and 8 viaducts, with 1,250,000 cubic yards of cutting, chiefly through 
rock, and 2,000,000 cubic yards of embankment. It has occupied seven 
years in construction. 
