Pine Bluff daily graphic., 1915-05-16

1 can one tel. when the proper amount has been added?
 Distilled water should be added be fore the battery is placed on charge. The solution should cover the plates. In some batteries the level is one-half inch higher than the tops of the plates. A battery can be tested at any time, and obviously the only way to tell whether it is fully charged or not is to test it in some manner, the gravity method usually being used.
 What part does gIycerin play in an anti freeze solution? Glycerin is used in anti-GreeZe sOlu- tions for the reason that it prevents The alcohol in such solutions from evap- orating rapidly and thus preserves the power of the mixture to resist the cold.
 1 would like to have you tell me why l have trouble in starting my car. when warm. Several times l have had to get help from some one who could spin it. Spinning always starts it, but this l am unable to do. It always starts readily if thrown into nigh when rolling down grade.
 The fact that you have no trouble in starting the motor when cold would in- dicate immediately that the trouble is not in the ignition system. If you will try slightly richer mixture on the car .ureter it may relieve the trouble. An other possible cause is that the valves may be adjusted too close so that when cold they close, but when warm there is an air leak that dilutes the mixture. | Carbon trouble also acts this way at | times, and if the motor has not been cleaned out lately it is suggested that the carbon be removed. Another possi- ble feature which does come under the head of ignition is that the dry bat teries may be weak.
 In drilling holes in pistons to make them lighter how much can bo taken off and how should they be drilled? You can safely drill eight three eighths inch holes equally spaced around the piston. In drilling place a cylindrical block of wood in the pis- ton, the wood just fitting. This will prevent the metal from cracking. You can hold the piston under the drill with your hands.
 Would a good iron rivet be suitable to rivet q front cross member to the frame on light car or should iI be put on with steel rivets?
 Good iron rivets would be suitable to use on the frame of light car. The principal stress endured by these rivets is one of sheer through the tend ency to rack on the part of the frame. A great deal depends upon the manner in which the riyeting is done. For instance, it has been shown in experimenting that rivet is 6.5 per cent weaker in a drilled hole than in a punched hole and that by rounding the edge of the rivet hole the apparent sheering resistance is increased 12 per cent. It is also true that shGering re- than for single sheer, and this is prob ably due to the unequal distribution of the stress on the two rivet sections. Experiments on the sheering strength of iron and steel rivetS would indicate that the proportion of iron to steel is as 19 to 22.1. This ratio is said to be Il valid only if the sheer is in plane perpendicular to the direction of roll ing, which would be approximately the case in your cross frame connec- ton.
 What are tn advantages and dsad- vantases of tie disk friction chain drive compared with other types of transmission now moro commonly used?
 The advantages of the friction trans mission are that it offers an infinite number of gear ratios, is silent, cheap to manufacture and simple. The dis advantage is that the friction disk must be renewed every few thousand miles. This is a small matter, but worth noting, and the amount of horsepower 1t will transmit under the conditions found in automobile design is limited. Therefore 1t has never been used to any extent on large cars, DuC mas 1Ounu IdNOr on some cars OI medium size and on more small cars.
 The gear set of my car is of the plan etary type. When the low apeed pedal is pushed down to start there is a knock heard from the gear set at resu- lar intervals. What is the cause of il?
 Owing to the speed of the motor in starting out on low speed the knock you speak of possibly is at the outer bearing or transmission shaft bearing, where the car is cranked. The dust and dirt continually working in this babbitt cut out the bearing sufficient ly to produce knock at this point. This bearing has babbitt lining and must be poured to fit the shaft.
 Please explain whether there would be any advantage gained by fitting I aluminium pistons?
 | Aluminium pistons are lighter and Il reduce the vibration because of their