ARTIFICIAL AIDS TO COMB-BUILDING 
177 
is next put into position, and its spout tacked with 
solder to the end of the jacket. The cover (co), 
perforated to pass the feedhole (/>^), is now, with sc, 
soldered to the water-chamber and around the wax 
feedhole, when all is complete. The advantages 
are these : In the old form, the amount of water 
contained could not be discovered, and hence boiling 
dry, and consequent unsoldering, was of frequent 
occurrence, when the structure was such that repair 
was almost impossible; here, the water is in full 
view, and if, by any chance, repairs are needed, un- 
soldering the covers and the junction between spout 
and jacket liberates the wax-chamber, and makes 
the whole business as simple as any tinker could 
desire. The spout is more convenient, since no angle 
exists to prevent it being brought up close to its 
work, while the water circulates freely round it, 
saving the wax from chilling. A clearing wire (cw) 
is kept in the water-chamber, to apply if any sub- 
stance should clog the narrow exit. The wax cannot 
run from the feedhole (f/i), and a ring of perforated 
metal (^, g) permits of the use of the smelter so soon 
as the contained water reaches the boiling point. A 
considerable block of solid wax is long melting, and 
the old model will not work satisfactorily till this 
operation is complete ; here, so soon as the water is 
of the required temperature, the molten wax will flow' 
freely, since the perforated ring holds the unmelted 
part of the block, in which it is embedded, away from 
the spout, in flowing through which the wax acquires 
the heat of the surrounding water. Those who have 
been troubled by old defects will best appreciate these 
VoL. II. N 
