Mr. Cuttriss read a paper on “Sound,” effectively illustrated by apparatus made chiefly by himself.

Beginning with a definition of sound he proceeded to give a short description of the construction of the ear, explaining how sound waves were received by the tympanum, the sensation thus produced being conveyed to the brain. The effect of the vibratory motion of sound waves was shown in a very simple, yet graphic manner.

The cause of the emission of sound by a tuning fork was then explained, and a simple method of recording its vibration exhibited. The reinforcement of sound and also its destruction by interference were then alluded to. The conduction of sound was demonstrated in various ways notably by the string telephone, whose usefulness is however limited to a distance of about 00 yards.

A sound wave to be recognised as a musical note must have at least 16 vibrations per second, a middle C tuning fork has 284, whilst the highest audible note has 38,000 vibrations per second. Various experiments were performed with the sanometer, the audiometer, and with a phonograph of simple construction, similar to that originally devised by Edison. The reproduction of the sounds spoken into the latter caused considerable interest and amusement.