108 JOINT APPLIED TO TUBES 



Another joint The apparatus of which I have given.a drawing and feftion 

 * in Plate VII. was made for conveying fleam from a boiler to 

 the fleam engine, and for many other philofophical purpofes, 

 in which this agent is very ufeful, though hitherto not much 

 applied to objecls of this nature. As I have found it very com- 

 modious, I fhould not be difpofed to make any remarks on the 

 contrivance itfelf, if its refemblance to fo many things that I 

 have feen, both in organization and effect, did not make it 

 proper to fay, that I fhould have let it pafs unpublifhed (among 

 the many arrangements, whether old or new, which every 

 practical mechanic finds himfeif induced to adopt in his opera- 

 tions) had not the confideration of utility made me fuppofe it 

 might prove acceptable. 

 Delineation. A j n Fig. 1, 2, and 3, the fame letters of the alphabet denote 

 ^ck with joints tne f ame things; Fig 1 exhibiting a view, Fig. 2 a feclion, 

 in the tubes, and Fig. 3 the plan of fome of the parts. The letter e fhews 

 wkh^fcrewandP 31 " 1 °^ an u P r 'g nt tuDe conveying fleam from the boiler into 

 a dilh fpring. the body of the cock c by its hollow cone m, which is open 

 beneath andclofed above, and has a fide aperture n communi- 

 cating, when duly placed, with the pipe It i. The cone is 

 prefled into its place by the cap b fcrewed on the body of 

 the cock c at r. The cap does not prefs immediately upon the 

 upper furface or fhoulder of the cone, becaufe the motion 

 would in that cafe be hard and uncertain ; but it a£ts by the 

 intervention of a fpring o in the fhape of a dim or flightly con- 

 cave place, which keeps it to its bearing with any required 

 degree of preflure accordingly as the cap is more or lefs fcrew- 

 ed down, and always with a mofl fmooth and pleafant action 

 ■without the leafl jerk or obflacle. The cock is turned by the 

 wooden handle or lever a, and is very fecure on account of 

 the large furface of the convex and concave cones which re- 

 mains imperforated. 



The pipe between h and i is connected by a joint, in which 

 g is a loofe cap milled on the outfide, and having a concave 

 fcrew on its inner furface. It is fcrewed upon the fixed piece 

 f, which is turned to fit it : In this laft piece is a cylindric 

 concavity furrounding the orifice of the pipe h (fee/, Fig. 3), 

 into which the piece p, at the extremity of the pipe i, loofely 

 fits. Upon the circular face of i are turned three or four grooves, 

 and the like on the correfpondent face of/. Thefe are of ufe 

 to fectire a fmall piece of tallowed linen cloth put between 



them. 



