The Birmingham age-herald., 1924-11-02
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What is servo brake?--W. ID. N.
 A servo mechanism uses the motion of the ear to apply the brake. In most cases the servo mechanism consists of small brake operated by the brake pedal. When the pedal is applied, the brake band or shoe tends to turn with Its drum, this pull being utilized to apply the brakes on the wheels. With this construction only a slight pedal pressure is required to apply the brakes. On the only American car equipped with servo mechanism gear oil pump IS mounted on the rear of the transmission and the pressure generated by It IS used to force out two pistons which i'll turn apply right and left sets of brakes. The pistons are located in cylinder be- meath the transmission.
 Why do some car manufacturers use internal front brakes and external rear brakes?-G. W. $.
 This construction is often used to avoid any trouble due to the expansion of the drums due to heating. The front drums expand away from their shoes and the rear drums expand toward their shoes so that the tendency of the rear brakes to tighten is offset by added looseness in the front brakes. This con- struction is often considered an advan- tage when the brakes are designated to work with 164 inch clearance instead of 1 .32 inch clearance heretofore almost universal for rear wheel brakes.
 Can you give me an accurate horse power formula "A. B. N.
 It is impossible to give you formula that is accurate because there are too many factors involved, but fairly good results may be obtained by using the following method: Multiply the bore by the bore by the stroke, by the num- Der of cylinders, by the number of revo- lutions per minutes and divide by 15,- 900.
 What is the function of an electrical cutout?-C. w. A.
 You probably refer to the reverse cur rent cut-out- relay, whcih lonk name IS usually shortened to cutout or relay. Its purpose is to close the circuit be- tween. generator and battery when the voltage produced by the generator is higher than battery voltage, and to open the circut when the generator voltage is less than battery voltage. It is usual Iy located on the generator and should close at high gear speed Of $ to lo miles per hour.
 The cooling system in my car seems to leak inasmuch as the water level gradually drops even when the car IS standing still. However, I am unable to find the leak. The engine also misses more or lesS.-S. NJ. E.
 It is rather certain that you have leak, between the water packet and the combustion chamber. Probably the trou- ble is due to a loose cylinder head or defective cylinder head gasket, although there is a slight chance that there is blowbole in the cylinder wall or cylinder head.
 When a car makes a mile record how do you figure the miles per hour?-P. H. J.
 Assuming, for example that the car did a mile in B seconds, the mile per hour rate may be obtained by dividing 53 into 3600 (since 3600 is the number of seconds in an hour). 3600 divided by 8 is 6S miles per hour, approxi- mately.
 What proportion of alcohol should I use in the radiator in order, to keep it from freezing-Ss T. T.
 The proportion depends on the freez- ing temperature which you wish to ob- tain, sas follows:
 Freezing Denatured Alcohol Taunarat1ra pintS Der gallon