HEATING BY HOT WATER. 175 
slotted or bored to receive the shanks of a couple of 
short bolts and nuts. A loose collar is also provided 
to slip over the spigot end of the next pipe, with a 
projecting ring and two lugs to correspond with those 
on the flange of the pipe. An indiarubber ring is passed 
round the spigot end of the next pipe, about an inch from 
the end, with the loose collar behind it, and this is then 
pushed into the socket of the other pipe, and the india- 
rubber ring is then compressed by tightening up the 
nuts until it grips the inner pipe tightly. This works all 
right when the nuts run easily on the bolts, but when 
they work stiffly they are a nuisance, and in any case the 
cement joints can be made both better and more quickly. 
—sae eo a 
Fie 1165. 
Fig. 114 shows Jones’ Improved Expansion joint, which 
possesses several advantages over the old or ordinary form. 
Ordinary flange-pipes are not much employed in hot-water: 
work, though there is no reason why they should not be, as 
they would answer the purpose quite as well as any other 
description. The expansion and contraction has to be 
reckoned with, of course, though this difficulty is easily sur- 
mounted ‘by using chairs with rollers, and in any case it is no 
worse than that taking place where socket-pipes are used. 
The pipes should always be laid as far as possible with 
the current; that is to say, so that this discharges from a 
spigot end into a socket, or with the socket of each length 
at the back or lower end, at any rate in the case of flow 
pipes. This is not, of course, absolutely indispensable, as 
