STERILISERS AND STERILISATION 11 
Upon the copper bottom of the vessel stands a low 
tin shelf pierced with holes. The bottles, when filled, 
stand on this shelf, and it prevents them from cracking, 
MERCIA PATENT STERILISER 
as they are liable to do, by coming into too close 
contact with the heating underneath. In the lid is an 
aperture in which is inserted a socket; into this socket 
is screwed (when it is required) a specially constructed 
thermometer, consisting of a long tube, the bulb of 
which reaches about midway down the bottles which 
