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Radio Record, Volume I, Issue 2, 29 July 1927, Page 14

A large number of excellent crystals are either partially or complztely spoiled in regard to their sensitivity by the method of mounting. The best of all inethods is to fix the crystal into the cup with that compound known es "Wood's metal,’ but unless this is done very carefully you will overheat the crystal and destroy its sensitivity. The best way to mount crystals in Wood’s metal is to take a few fragments (sufficient to half fill the cup) and then to hold a hot soldering iron, poker or, indeed, anything hot enough, against the eutside of the cup until the Wood’s metal inside just begins to melt. Immediately it melts, remove the soldering iron, wait a second or two, and then press the crystal into the Wood’s metal with the aid of a pair of tweezers. The pressure of the crystal will make the melted metal rise up round it aud when it sets the crystal will be properly secured.