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the joint foon decaying, even when the taper end is fitted 
perfectly, becaufe the thicknefs of the wood at the taper 
partis fo very frnall. In the ufual mode of fitting them, 
by merely (haping the conical part with the axe and 
drawing-knife, whilft the workmen are perhaps over (hoes 
in mud, and expofed to bad weather, it is fcarcely reafon- 
able to expe£t them to be very attentive; but the joint is 
fitted in hade, and difpatched as quick as poflible: the 
confequence is, that the conical part being corre&ly bored, 
whilft the taper is made to an irregular and more obtufe 
cone, the joint fits only at a very narrow point; but, if 
well driven, will make a tight fitting at firft, and, when 
buried, efcapes detection ; bur, in the courfe of a very few 
years, the vacant (pace round the end of the taper accu¬ 
mulates mud, which haftens the decay of the wood, and 
the joint fails. From thefe circumftances, the pavement 
of our ftreets is conftantly broken up, the way impeded, 
and the fupply of water fufpended. The Society of Arts 
have, under thefe conliderations, offered a handfome pre¬ 
mium, for feveral years paft, to procure a complete 
remedy for thefe defedts. Mr. Hornblower propofed a 
tool, or bit, to form the taper end of the pipe, with the 
fame certainty as the cone which is bored. It confided of 
a wooden plug, fitted to the bore of the pipe, and having 
through its centre a hole, for the reception of a round 
iron rod or axis, which has a crofs handle at the end, like 
an auger, to turn it round by. Near the handle, its fize 
is fufficiently enlarged to have a mortife, for the admiflion 
of an iron arm, which can be fixed in it by a wedge. This 
arm turns down, and carries a fteel knife, the edge of 
which, by the bending, ftands inclined to the round rod, 
in the angle the conical taper is to have : therefore, by 
turning the handle round, the edge of the knife defcribes 
the furface of the cone, and cuts away the wood of the 
pipe to that form ; the round rod, being of confiderable 
length, can Hide freely in the plug at the end of the pipe, 
and allow the cutter to be thruft up, to cut by degrees, 
till it reduces the taper. The ufe of this tool would 
enfure the perfect fitting of the joints ; but ftill the plan 
is defective, as before mentioned, from the frnall quantity 
of wood round the joint. Another kind of joints have, 
therefore, been propofed : in thefe the adjacent ends of 
the pipes to be joined are both bored out, by a taper bit, 
to hollow cones;' and the two are united by a (hort iron 
tube, which is made in form of two truncated cones joined 
at their bafes, and of dimenfions correfpondent with the 
conical bafes in the ends of the pipes. This plan is very 
far preferable to the former, both in ftrength and durabi¬ 
lity ; and, as the tubes are made of caft-iron, it is not an 
expenlive one. 
Meflrs. Eckhardt and Lyon obtained a patent in 1806, 
for a method of making wooden pipes by feparate ftaves, 
refembling a barrel, but of lefs curvature, and greater 
proportional length, fo as to approach near to a cylindri¬ 
cal form, particularly withinfide. They are to be bound 
by iron hoops, made faft either by driving them on from 
the ends, or by ferewingthe hoops together: the lengths 
are to be joined together, by forming one end of each 
taper, and enlarging the correfponding ends of others to 
receive them : the ftaves are to be fitted by tongues, ra- 
bitting, or dovetailing. We have not heard of this me¬ 
thod having been pradfifed to any extent: it would, we 
think, be very expenfive, and have all the defeats of wood 
pipes; being liable to fpeedy decay, when buried in the 
ground. And'it generally happens, that in their rotten 
or decayed parts, they generate infedts and animalcules in 
vaft numbers; which may always be difeovered in water 
that has pafled through wood pipes or pumps which have 
been long in ufe. Dr. Buchan obferves, that fuch u'ater 
becomes putrid by the corruption of the animal and vege¬ 
table bodies with which it abounds. 
As the following communication fuggefts a fimple me¬ 
thod, probably but little known, of preferving wooden 
water-pipes, and preventing their being clioaked up, it is 
here inferted, “ I have been impelled by neceftity, which 
P E. 
is juftly faid to be the mother of invention, to find out 
fome remedy to keep wooden pipes, laid under ground, 
clear, that the water may not be impeded in its courfe, 
as is always found to be the cafe, wherever they are ne- 
ceflary, on account of the roughnefs left by the operation 
of boring. It is that roughnefs which chiefly ferves to 
collect and accumulate the decayed vegetables, and other 
extraneous matter contained in the water. Henderfon, 
Semple, and Company, of Kincaid Printfield, (whofe prin¬ 
cipal fervant I am,) having about 800 feet of pipes to lay, 
and it being my duty to attend the management thereof, 
I fuggefted the following plan, to prevent the great lofs 
above mentioned. I procured for the purpofe two pieces 
of caft-iron, one foot long each, that juft filled the bore, 
which was three inches diameter; after making them 
red-hot, I pufhed them backward and forward, by means 
of a long rod, until they loft a part of their heat; this I 
repeatecl a fecond time in the fame pipe, which not only 
completely finged, but coated the infide with a membrane 
not inferior to pitch. The heat being great, and no room 
left for combuftion taking place, the rofin was in part 
extracted, and, by the irons being (lowly moved, the bore 
became black, glazed, and perfedfly fmooth. Every 
perfon who has feen the eftedt, highly approves thereof. 
John Buchannan.” 
Iron Pipes are call at the iron-founderies of any dimen¬ 
fions ; and for durability and ftrength combined, are 
greatly fuperior to any other material : they may be pro¬ 
cured in lengths of ten feet, and united by nuts and 
ferews pafled through (launches caft on the ends of them. 
Mod of the great companies for fupplying London with 
water have, within thefe few years paft, adopted caft-iron 
pipes for their mains, and are daily increafing them, 
under the convidfion that their permanency will compen- 
fate for the firft expenfe. They are ufually caft in lengths 
of ten feet, one end with an enlarged focket of fufficient 
fize to receive the end of the next pipe. As thefe joints 
cannot be driven clofe, to fit like wooden joints, they 
require fome cement. To apply this, they firft caulk it, 
by driving a frnall quantity of hemp down to the bottom 
of the joint with a blunt chifel, and then fill the remain¬ 
der of the focket with iron cement; which is a compofi- 
tion of borings or turnings of caft-iron, mixed up with 
fulphurand fal ammoniac. This is moiftened with water, 
and rammed into the cavity; and the rapid oxydation of 
the iron-borings unites them into one mafs, and at the 
fame time expands the bulk of the cement, fo as to fill 
up all the fpace veryclofely. The hemp, firft driven into 
the joint, is only to prevent the cement getting into the 
pipe, and to keep the water from it till it is let firmly; 
after which, the joint is as folid as any other part of 
the pipe. Another method, much ufed for large pipes, is 
to have two ears projecting from each pipe at the joint, 
through which ferew-bolts are pafled, to draw them clofe 
together. The joints are fometimes filled with lead run 
in, whilft melted; and others have ufed the Roman 
cement to bed the joints in. 
Within thefe few years immenfe quantities of iron 
pipes have been laid in all parts of London, for the con¬ 
veyance of water, which no fooner became generally 
known, than great prejudices were excited againft them, 
under the idea that they would give the water a metallic 
tafte, which w'ould be injurious to the health of the inha¬ 
bitants. This is clearly an error, as any one may afeer- 
tain, by examining an old ciftern, or veflel of caft iron, 
which has only had frefli Thames water in it; and they 
will find it coated with a fort of Japan, or fmooth furface 
of a black colour, which is a very thin oxyd, and does not 
penetrate any depth : though, if the water is of fuch a 
quality as to produce red ruff, the iron is corroded very 
faft, but is ftill a very harmlefs mixture. Water having 
any lime in it depofits a thin coat or incruftation within¬ 
fide iron pipes, and thus completely defends them from 
corrofion ; nor is there any danger, as fome have fuppofed, 
of this incruftation increafing fo as to flop the pipes in 
courfe 
