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POPULAR SCIENCE REVIEW. 
to raise water were found in abundance. The wood, owing it is thought to 
penetration by copper, is in a perfect state of preservation, and there 
appears to be evidence that the wheels were worked by a number of men 
stepping on the flanges somewhat after the manner of prisoners on a tread- 
mill. There were eight of these water-wheels, the water being raised by the 
first into the first basin, by the second into the second basin, and so on, till 
it was conveyed out of the mine. The age of these relics has been set down 
at 1,500 years. 
An Improved Mode of Manufacturing Steel Tyres. — Some useful im- 
provements have been suggested in a paper read by Mr. John Ramsbottom, 
at a meeting of the Institution of Mechanical Engineers , on the 31st of July. 
Mr. Ramsbottom, who is the Superintendent of the Engineering Works of the 
London and North-Western Railway Co. at Crewe, stated that his object 
was the reduction to an insignificant amount of the waste of material in the 
processes of manufacture, compared with the weight of the ingot of steel 
employed, and also to ensure the production of finished tyres of the required 
dimensions. A third advantage sought, was the reduction of the time 
hitherto necessary in the operation. The ingots were made for Bessemer 
steel, cast in conical moulds, 22in. diameter at the base, and 22in. high, the 
apex of the cone being cut off at 6in. diameter, and thus forming the open- 
ing for filling the mould. This was sufficient to make a 5ft. tyre. The 
moulds are of cast-iron, protected in various ways, the centre of the base 
being covered with fire-clay, which can be readily renewed. The ingot is 
then first hammered laterally, all round the lower edge of the cone, to 
consolidate the skin of the metal, after which it is forcibly hammered in 
the direction of its axis, and reduced to 9in. in height, with a 10-tons duplex 
hammer — or two hammers, each of this weight, meeting horizontally. The 
ingot, during this powerful treatment, is supported upon a carriage, and 
can be readily made to rotate, as required. At a further stage, a hole is 
punched in the centre, to form it into a ring, this centre opening being 
gradually enlarged, by a conical punch and the aid of a beck-anvil. When 
the bloom is brought to 34in. diameter, and the centre hole to 19in. 
diameter, it is then removed to a circular rolling-mill, which was invented 
by Mr., Roth well Jackson, a member of the institute, where it is rolled into 
a finished tyre, both outside and inside ; the latter operation is completed 
in one heat, of about 5^ minutes. The whole process from the cast ingot 
is accomplished in four heats, and it was stated that on one occasion six 
tyres were made in 5 hours and 12 minutes. The quality of the steel is 
believed to be improved in the operation. 
MICROSCOPY. 
A Mechanical Finger for delicate microscopic manipulation has been 
devised by Mr. Smith, of Kenyon College, U.S., the inventor of the apparatus 
for illuminating opaque objects under the highest powers. We cannot 
