212 REPORT—1840. 
to employ return tubes, as well as direct tubes, for heating the water. 
The advantages are said to be, that no water is carried with the steam 
into the cylinder, and a saving of fuel, through the arrangement of the 
tubes, from 30 to 40 per cent. 
On Wrought-Iron Wheels for Locomotive Engines. By Mr. Grime. 
In this communication Mr. Grime detailed the construction, and 
discussed the advantages, of an entire wrought-iron wheel, suitable for 
engines, tenders, &c., for which he has obtained a patent. 
Account of a Railway Wheel with Wood Tyre. By Mr. Dircxs. 
The construction of the wheel will be understood by imagining 
an ordinary spoked wheel, but with a deep-chanmelled tyre. In this 
channel are inserted blocks of African oak, measuring about 4 x 32 
inches, prepared by filling the pores with such unctuous preparations 
as counteract the effects of capillary attraction in regard to wet or 
damp. The blocks are cut so as to fit very exactly, with the grain 
placed vertically throughout, forming a kind of wooden tyre. There 
are about thirty blocks of wood round each wheel, where they are re- 
tained in their places by bolts, the two sides of the channel having cor- 
responding holes drilled through them for this purpose ; each block of 
wood is thus fastened by one or two bolts, which are afterwards well 
rivetted. After being so fitted, the wheel is put into a lathe, and 
turned in the ordinary manner of turning iron tyres, when it acquires 
all the appearance of a common railway wheel, but with an outer 
wooden rim, and the flange only of iron. Mr. Dircks proposes the use 
of either hard or soft woods, and of various chemical preparations to 
preveut the admission of water into the pores of the wood: he also 
contemplates the using of wood well compressed. A wheel was ex- 
hibited, one of a set which had been in use for two months, carrying 
five tons daily. 
On a new Step-Rail, and Railway Carriages. By Mr. Couzs. 
Mr. Coles proposed to introduce friction wheels ; and that, except- 
ing the first and last carriage in the train, the carriages should run on 
two wheels. He also proposes a step-rail at the curves or bends, to 
have the effect of reducing them to cants. Mr. Coles described 
minutely the plan thus noticed, and discussed the expected advantages. 
On an Improvement on the Air-Pump. By Mr. Lane. 
