III
HIS MUSICAL-BOX
In steps Science, and says to the Cricket bluntly:
“Show us your musical-box.”
Like all things of real value, it is very simple. It is based on the same principle as that of the Grasshoppers: a bow with a hook to it, and a vibrating membrane. The right wing-case overlaps the left and covers it almost completely, except where it folds back sharply and encases the insect’s side. It is the opposite arrangement to that which we find in the Green Grasshopper, the Decticus, and their kinsmen. The Cricket is right-handed, the others left-handed.
The two wing-cases are made in exactly the same way. To know one is to know the other. They lie flat on the insect’s back, and slant suddenly at the side in a right-angled fold, encircling the body with a delicately veined pinion.
If you hold one of these wing-cases up to the light you will see that is it a very pale red, save for two large adjoining spaces; a larger, triangular one in front, and a smaller, oval one at the back. They are crossed by [[190]]faint wrinkles. These two spaces are the sounding-boards, or drums. The skin is finer here than elsewhere, and transparent, though of a somewhat smoky tint.
At the hinder edge of the front part are two curved, parallel veins, with a cavity between them. This cavity contains five or six little black wrinkles that look like the rungs of a tiny ladder. They supply friction: they intensify the vibration by increasing the number of points touched by the bow.
On the lower surface one of the two veins that surround the cavity of the rungs becomes a rib cut into the shape of a hook. This is the bow. It is provided with about a hundred and fifty triangular teeth of exquisite geometrical regularity.
It is a fine instrument indeed. The hundred and fifty teeth of the bow, biting into the rungs of the opposite wing-case, set the four drums in motion at one and the same time, the lower pair by direct friction, the upper pair by the shaking of the friction-apparatus. What a rush of sound! The Cricket with his four drums throws his music to a distance of some hundreds of yards.