The hook should move freely up and down between two contacts (marked 1 and 2 in Figure 94). These contacts are simply two small brass strips bent at right angles and fastened about an inch apart along the left hand edge of the wooden back by means of two small round headed brass wood screws. The position of the contacts should be such that the hook is in a horizontal position when it is half way between the two. A small spring is arranged so as to pull the hook up against the upper contact (No. 1) when the receiver is lifted off. When the receiver is hung on the hook, it should overcome the lift of the spring and pull the hook down against the lower contact (No. 2). *The Receiver* may be purchased at almost any reliable electrical supply house. It should be provided with a ring so that it can be hung onto the hook. *The Transmitter* is preferably of the "solid back" long distance type. It also can be purchased ready made from almost any electrical supply house. The transmitter is mounted on the wooden back directly under the hook. It is marked T in Figure 94. *A Push Button*, made out of two round headed brass wood screws and a strip of spring brass as shown in Figure 96, is mounted to the right of the transmitter. One end of the spring is fastened down firmly with a screw, the other end is bent so that it is directly over but does not touch the second screw mounted about seven-eighths of an inch away. Four binding posts should be arranged along the bottom of the wooden back and two more just to the left of the transmitter. The set is now ready to "wire" or connect. The connections can be understood best by following the diagrams in Figures 94 and 97. Starting with the four binding posts along the bottom of the back, mark the left hand one B1, mark the next one B2, the third E and the fourth L. Connect a wire from binding post B1 to the post P1 directly above it. Run the wire from P1 to the brass strip on the push button. Connect binding posts B2 and E together and from E run a wire to the right hand binding post on the bell. Connect a wire from the left hand post on the bell to the lower contact 2. The hook should be connected to binding post L. The upper contact 1 is connected to one terminal of the transmitter. The other terminal of the transmitter goes to binding post P2. The telephone receiver should be connected to the posts P1 and P2 by means, of flexible wire. The contact on the push button should be connected to the upper hook contact 1. The set is now complete, ready to connect to a similar outfit. The battery is connected to the binding posts marked B1 and B2. E and L are the line posts to which the wires connecting the two sets are led. The wire connecting the two outfits should not be smaller than No. 18 B. & S. gauge. No. 14 will prove better if the line is a long one. The wire should be very carefully insulated. Ordinary porcelain knobs will serve as suitable insulators.