"On the button" Quotes from Famous Books
 ... Knowing the latter to be extremely sensitive to minute changes of pressure, for example, those of sonorous vibrations, he conceived the idea of measuring radiant heat by causing it to elongate a thin bar or strip of metal or vulcanite, bearing at one end on the button. To indicate the effect, he included a galvanometer in the circuit of the battery and the button. The apparatus consisted of a telephone button placed between two discs of platinum and connected in circuit ...
— Heroes of the Telegraph • J. Munro |
