QUARTZ FIRRKS A\T> ITS TRNfPKRATURE COEFFICIENT. 11 H 



between the two capillary tubes and cut through at about 1 centinj. from the end, so 

 as to leave this 1 centim. of the fibre lying transversely between the glass tubes. 



Fig. 3. 



Fig. 4. 



About 1 millim. of the end nearest to the observer of this piece of the fibre is then 

 turned up at right angles to its length by means of a very small gas flame. This 



