1817.] Scientific Intelligence. 327 
the passage of the gas, where a great degree of heat is requisite, 
that will not expose the operator to any chance of explosion ; using, 
at the same time, Professor Cumming’s safety cylinder containing 
oil. Itis this: let A B represent a fagot of capillary brass tubes, 
with the smallest possible diameters, all communicating with one 
tube at C, whose diameter, at the least, should equal 1. of an inch, 
Fagot of capillary tubes. Jet, 
and the whole being on the outside of the stop-cock, D, of the jet, 
it will be evident that, if the gas in the tube C be exploded, there 
will only be a partial detonation, extending its effects only as far 
as B. 
Epwarp Daniget CLARKE. 
IV. Canvas Tubes for conveying Water. 
(To Dr, Thomson.) 
SIR, Glasgow, Jan, 1817. 
Some time ago one of your correspondents gave much credit to 
the French nation for superior ingenuity, in exemplification of 
which he gives them the sole merit of inventing and using canvas 
tubes for conveying water. That these tubes may have been used 
by the French, cannot be denied; though I must be allowed to say 
that they are seldom either deficient, or very just, in making such 
claims; but at what period these tubes were used in France, your 
Correspondent has not stated. About 1800 or 1801, I proposed to 
Mr. John Wood, ship-builder, Port Glasgow, the application of 
these tubes as the best mode of obviating the difficulties experienced 
by seamen in supplying themselves with water on foreign, difficult 
coasts. Mr. Wood said that he had for many years used them for 
filling from the adjacent harbour holds of vessels under repair. As 
these canvas tubes appear to be but partially known, permit me 
shortly to state the plan. Let vessels be provided with pipes of 
necessary length, and of about two inches diameter, made of 
canvas, without any paint, and with a small portable tin or copper 
ump, 21 or 3 inches in diameter, and about eight or nine inches 
in length of stroke. By this simple apparatus water may be easily 
and expeditiously conveyed to their boats without landing casks, &c.; 
also casks in the vessel’s hold may be filled from the boat without 
altering the stowage ; thereby saving much tear and wear, besides 
much dangerous, and at times unsuccessful, labour. From the 
lightness, cheapness, facility of construction, and durability, of 
these tubes, may they not be successfully applied to the ventilation 
of coal-mines, as well as to various other useful purposes? After 
such celebrated men have been labouring towards improvement in 
. 
