122 History of Mechanical Inventions and Useful Processes. 
Fig. 10 of Plate I. represents the method of joining two block- 
tin pipes A, B at C. D is the connecting ferrule, made of brass, 
about sjth of an inch thick, turned to a knife-edge at both ends, 
leaving the centre ridge the whole thickness of the brass. E, Fig. 
11, is a steel mandril, turned from 1 to 2, exactly to fit the bore 
of the pipe ; it is bevelled from 2 to 3, the same as the connect- 
ing ferrule. When you make the joint, drive the mandril into 
the pipe up to the mark 3 ; take out the mandril, and the pipe 
will have a bevel corresponding to the slope of the ferrule. This 
being done at both ends of the pipe, insert the ferrule, and press 
the pipe close : the inner surface of the pipe and the outer sur- 
face of the ferrule being true to each other, the joint will now 
be air-tight, when it is very easily soldered, and, when done, is 
fully stronger than any other part of the pipe. When it is re- 
quired for conveying liquids, the ferrules are tinned. By this me- 
thod the joints are very easily made, and there is no risk of making 
a bad one, or any possibility of the internal diameter of the pipe 
being diminished, by solder getting in at the joints. These fer- 
rules are made from a penny each and upwards, according to 
the size of the pipe. 
3. Description of a New Shower-Bath. By Mr John Murray, 
Lecturer on Chemistry, &c. 
In Fig. 12, Plate I. is represented a shower-bath on, I believe, 
a new principle. The figure exhibits a cistern C, to be filled 
with water for the purpose of supplying the machine, together 
with a stopcock S, to let that water occasionally run off. Over 
this is placed a shallow basin B, serving as a complete cover 
for the cistern, and having a slip or false perforated bottom, 
through which the falling water percolates, and forms at the 
same time the platform on which the patient stands. 
Towards the summit is a vase V, with a perforated bottom, 
(there may be reserve ones with apertures of varying diameter, 
to screw and unscrew at pleasure, so as to modify the shower 
and shock for specific purposes), and to this vase, above is at- 
tached a lever L, which, by means of a spring, shuts an 
aperture somewhat in the manner of a flute key ; the lever is 
managed by means of a cord M at its extremity. 
The vase, when it is to be supplied with water, is lowered into 
the cistern by means of a small winch W : this winch has a recoil 
