ON THE VIBRATIONS OF BODS, PLATES, ETC. 127
knowledge of the similar fact in the analogous case of organ pipes, renders it easy to ascertain the velocities of sound in different gases.
Rods vibrating laterally and (1) fixed at both ends may vibrate in 1, 2, 3, 4, 5, &c, segments. If (2) free at both ends they can vibrate only in 3, 4, 5, 6, &c, segments. Reckoning the two fixed ends in the former case as nodes, the vibration rates of the segments are as follows:
When fixed at one end only, the vibration number varies inversely as the square of the length, and the overtones are very distant from one another and from the fundamental.
The 1st overtone of the tuning-fork is more than two octaves above the fundamental, and the 2nd overtone more than an octave above the 1st.
The pitch of the tuning-fork is very slightly affected by ordinary changes of temperature.