Now when you lay the tips of your fingers flat on the rim of a glass and rub them around it, the friction between the skin of your roughened fingers and the edge of the glass will set the latter into vibration and a wonderfully sweet tone will be sent out. By varying the pressure of your fingers on the glasses you can produce a very beautiful tremolo effect.
It is a good scheme to put a few drops of acetic acid into each goblet so that just as quickly as the volume of sound begins to fall off you can dip your finger tips into whatever glass they are nearest to and so increase the friction between them and the glass.
If you can play a set of musical glasses well your services will be in demand for all kinds of entertainments.
The Tubular Harp.
—How to Make It.
—This easily made instrument gives out tones very much like those of the musical glasses but they are much deeper and louder.
Fig. 109 a, b. the harp of a thousand thrills
To make this harp you will need 12 feet of ¹⁄₂ inch bell-metal[110] tube—brass tube will do but it is not as good—and cut it into eight pieces; saw off the first tube 2 feet long and cut off each of the other pieces ¹⁄₂ an inch shorter than the one before it. Cylindrical sticks of wood can also be used for the tubes.
[110] Brass and bell metal tubing can be bought of the U. T. Hungerford Brass & Copper Co., 89 Lafayette St., New York.