By adopting a basis of averages which shall be general among members of this association, the charges for a constant horse power of current may vary with the circumstances of its first cost in each case, but the general classification of motor service may be a comparatively fixed rule. I am not prepared to say that this is the best plan to follow, but respectfully submit the following as a possible solution of the frequently asked question, "How shall we charge for electric motor service?" * * * * * EXHAUST FANS. First on the list of power consumers is the exhaust fan, taking it in average use. There are, however, circumstances under which its use will be limited to as low as 70 or 75 per cent. of its contract hours of service. As, for instance, in a dining room it may be cut out except during meal hours, or entirely cut out on cool days. In places of this description, however, its contract use is usually limited to five or six months in the year, and other than electric power is, by circumstances of first cost and inconvenience, but a feeble competitor. The first four applications on the accompanying list, viz., exhaust fans, blowers, ceiling fans, and fan outfits, are all more or less subject to the foregoing conditions, and therefore currents supplied to motors for these purposes command the maximum price per horse power. One important feature in the installation of ceiling fans is the countershafting to the motor. In one recent case we had a complaint from a customer that the half horse power motor sent him would not drive the ceiling fans, and that the motor must be defective, and should he return it for repairs. We immediately sent a representative to find out the difficulty, which was found, as is usual in such cases, in the countershafting, or rather the want of it. The 3 in. pulley on the motor was connected to a 6 in. pulley on the line shafting. The rated speed of the motor was 2,000 revolutions, and had it been able to develop this speed, would have driven the line shaft 1,000 revolutions and the fans a relative speed. To accomplish this would probably require a motor of 3 or 4 H. P. The line shafting driving ceiling fans usually runs about 75 revolutions. To give this speed on the line shaft with a rated speed of 2,000 on the 3 in. pulley of the motor would require a countershaft with a 24 in. pulley belted to the motor. On the same countershaft should be a 5 in. pulley belted to a 15 or 16 in. pulley on the line shaft. Fully three-fourths of the trouble found in electric motors arises from improper shafting and belting. The average make of 30 in. exhaust wheel, a ½ H. P. motor should drive about 400 revolutions. Say, then, the speed of the motor is 2,000 and the pulley 3 in., it would require a 15 in. pulley on the fan to do the work. A 36 in. wheel requires 1 H. P. to develop the same speed. If the motor speed is 1,800, the pulley 4 in., it would require an 18 in.