The cover is put in place and wax is well crowded in between it and the
rim of the opening. The wax is preferably prepared in long rolls about
the size of a lead-pencil and 25 to 30 centimeters long. This is crowded
into place, a flat knife being used if necessary. An ordinary
soldering-iron, which has previously been moderately heated in a gas
flame, is then used to melt the wax into place. This process must be
carried out with the utmost care and caution, as the slightest pinhole
through the wax will vitiate the results. The sealing is examined
carefully with an electric light and preferably by two persons
independently. After the sealing is assured, the plugs connecting the
thermal junctions and heating wires of the cover with those of the
remainder of the chamber are connected, the water-pipe is put in place,
and the unions well screwed together. After seeing that the electrical
connections can not in any way become short-circuited on either the
metal chamber or metal pipes, the asbestos cover is put in place.