It is demanded of lubricating oils that they shall not attack metals, that their chemical composition shall not be altered by high temperature and above all that they shall not contain oil of resin. For the latter requirement no other reason is given than that perhaps the oil of resin is more volatile than the rest and may contribute to "cracking" as well as increase the total consumption. Its density is however, 938, while the pure mineral oils with which it is found mixed have a specific gravity of only 900 to 925. In practice scarcely any other means are employed for testing lubricating oils than to use a sample of one for a day's journey, to force the speed of the vehicle and to examine in the evening the metallic surfaces and the residues. A chemical test has fewer inconveniences. The lubricating oils usually belong to the paraffine group of petroleum distillates. They are always thick and brown. but of a shade varying with the angle of the light. They get thinner with heat and are finally evaporated into thick fumes, as one may observe by heating a drop on a piece of paper over the flame of a candle. They are easily soluble in ether and this permits a ready examination for foreign corpuscles, and gives a chance for dosing them chemically. Every insoluble ingredient is at least suspicious and everything infusible is harmful. Only graphite, among infusible ingredients, is tolerated on account of its lubrifying properties. But one should be circumspect with regard to graphite, partly because there are gritty and impure brands in the trade, and partly because this substance lends itself to other adulterations. At any event, the adulteration with oil of resin remains always the most difficult to detect, and it is a practical method to this end which is most required. The method proposed rests upon the colored reaction for resin given by Mr. Sans of the Laboratory for Resins at Bordeaux (Annales de chimie analytique, 1909; page 100). The author describes it as follows: "If a very small quantity of resin is added in a test tube containing one or two cubic centimeters of neutral sulphate of methyl, and the tube is slightly heated, there is observed a coloration passing from rose to violet and deep violet and which disappears when the temperature is raised, leaving only a slight brownish shade."

By

Under similar conditions slight traces of oil of resin give practically the same reaction, without reaching the deep violet, however. If the oil is emulsified in water, the reaction is plain without heating. But if it is dissolved in alcohol, no coloration appears. To apply these properties to a test, one proceeds as follows: Pour 3 to 5 grammes of the suspected oil in a tube, and on top thereof about five times as much of 60 proof alcohol; close with a stopper and heat in a wet-bath to 40 to 50 degrees centigrade, so as to render the oil more fluid, and shake until an emulsion is formed. This is now cooled in water, and fatty globules separate themselves from the medium. turning the tube gently up and down three or four times, the globules are made to form a single mass, which rises to the top or sinks to the bottom of the liquid, according to the specific gravity of the oil. The whole contents are now thrown on a filter, and the liquid runs off rapidly and is received in a capsule, which is heated in a wet-bath until the alcohol alone has disappeared, and the residue is then allowed to cool. If then, into this water without alcohol, there is dropped sulphate of methyl the appearance of red color shows the presence of oil of resin. The color vanishes rather quickly after the first few drops, but by adding more, up to 2 to 3 cubic centimeters, the

of

use

color reappears with increased intensity and more lasting. It should be remembered that there will be no reaction with alcohol 90 to 95 proof. Even with the 60 proof alcohol it is reduced, and it may not appear if the desiccation of this alcoholic extract is complete. The use of 60 proof alcohol is necessary so as to avoid any dissolution of the paraffine oil, and the preservation of the water in this alcohol, after one-half its volume has been evaporated, is required to get the most sensitive reaction. Synthetic experiments with this method have shown that it will detect an admixture of one per cent. or even less of resin oil to a lubricant.-Les Sports, June 8. "At the present stage of hydrodynamics, direct and quantitative application of theoretic knowledge to aeronautic struction problems is rarely possible. Only qualitative explanations of a general nature and experimentally ascertained figures are in question." In other words, without circumlocation, most formulas relating to flight problems and pretending to give mathematical relations of the forces involved in atmospheric thrusts are as yet buncombe. From an article on the present stage of the "science of aviation,” by Diplom-Engineer F. Bendemann in Zeitschrift des Vereines Deutscher Ingenieure.

con

Acetylene is one of the substances promising best results in the production of synthetic rubber, and there is some hope in this fact for the languishing calcium carbide industry.Engineering (London), May 13.

A cooling medium boiling at 170 degrees centigrade instead of 100 degrees, as water, and suitable for use in the waterjackets of automobile engines, has been devised by Mr. Boursin and tried out in a long series of experiments at the Conservatory of Arts and Trades. For example, a motor was first operated cooled to an exterior temperature of 168 degrees by means of Boursin's mixture, and a quarter hour afterwards the same motor was cooled with water. Observations were first taken after one hour of running. The average r.p.m. was 1130, the power 4.22 hp., the gasoline consumed in two hours 3.054 kilograms. The metal radiator maintained a constant temperature of 40 degrees. With water in the jacket, observation was commenced when the water had reached 93 degrees. The chief of the laboratory advanced the ignition two notches. The r.p.m. was 1160, the power 4.25 hp., the consumption of gasoline 3.557 kilograms. With about equal power the gasoline consumption with water cooling had increased 16 per cent. At a renewed trial with the new cooling mixture, 3 millimeters was added to the lift of the exhaust valves, and the gasoline consumption went down to 2.700 kilograms, while the power was somewhat increased. From these tests one may draw some conclusions. The temperature of the exhaust is raised, fewer calories are absorbed by the walls and the efficiency is increased. Hence, to get all the advantages offered by using a cooling medium of high boiling point, reduce the length of the suction stroke while keeping the compression unchanged, and the fuel economy will be improved. Or, if it is desired to increase the power at equal fuel cost, increase the areas of the ports. In fact, ports sufficient for a water-cooled motor are no longer sufficient for a motor working at higher temperatures, whether through air-cooling or use of a cooling medium like Boursin's. In the complete reports of this investigator, a theoretical accounting for the various heat losses under the different conditions is promised.-La Vie Automobile, June 11.

ANY an

automobilist has wished for a self-starting

M device, and has scoured the market in search of one,

without success. Similarly there are many who desire a source of pressure, such as is not supplied with the car. This want can be supplied by any handy man who can select materials and fit them to his car in a proper manner, a contract which nearly any real American would undertake.

The materials necessary to make and fit to the car the source of pressure supply shown in the appended cut are few, consisting of a stout tank of perhaps two to three cubic feet capacity. In addition to this, there is needed a stop cock, a non-return valve, a drain cock for the tank, a gauge, and the necessary lengths of heavy copper tubing of 1-4 inch or smaller diameter. The stop cock is screwed into the top of the cylinder, and a pipe leads from there to the tank, located in any suitable and convenient place. Just ahead of the tank is placed the nonreturn valve, to prevent the pressure from escaping back to the cylinder during the suction and other strokes when the pressure is likely to be lower than that in the tank. The drain

Non Return Valve

Stop Cock

Reservoir

Cylinder

Drain Cock

Supply Pipe

Elements of Pressure Storage System of Utility

should be fitted to one end of the tank, near or at the lowest point, so as to draw off the water of condensation.

From another point of the tank the pressure gauge is led, and, also, the supply pipe. If the pressure is to be used for pumping tires, for cleaning off dust, or for blowing the horn, the pipe would naturally lead forward to somewhere near the dashboard. On the other hand, if the automobilist is ambitious and wants to fit a starting device, the supply pipe should lead to a distributor placed directly upon the dash.

The pressure gauge, although shown close to the tank, would preferably be located on the dash and fastened to it, this being only a matter of piping.

Lost motion takes place when relative parts are lacking in harmonious adjustment. The effect of lost motion in any machine is usually to rack the machine to pieces long before it would wear out if proper attention were given to the alignment, lubrication, and adjustment of its parts. Where there is lost motion there is often danger; excessive wear, noise, and inefficiency are its accompaniments; and

many a serious accident has been traced directly to neglected lost motion in the steering gear. "Why is the repair shop so very prevalent?" The answer may be, "Chiefly because of lost motion." The life and safety of any bearing decrease as the lost motion increases. Therefore, do not neglect lost motion.

It frequently happens that a horn becomes dented. To restore it to its normal shape it is usually sent to a musical-instrument maker or to the manufacturer of the horn, which is not only expensive but also involves considerable loss of time. By the following method dents can be removed from the "bell” of a horn in the garage or at home. The materials necessary are a length of strong half-inch wire, solder, a blow torch and vise. The wire is bent into a loop of about the size of the dented portion at one end and is then soldered to the dented portion. The wire is then gripped in a vise or wrapped around another piece, to prevent the wire running through the jaws of the vise. The horn is now grasped with both hands, and a series of gentle pulls in the direction of the arrow will bring the bell to its original contour. The solder is then melted with the blow torch, when the wire loop comes away, and the operation is finished, except for polishing.

Amateurs really should learn to take care of the component parts of the water system. The diagram below shows the whole water system of a well-known car, in which the water is filled into the usual filling cap, flows downward and back to a centrifugal pump, is there projected up to the bottoms of the cylinders, whence it carries off the heat, loses in specific gravity, rises and flows out through the upper water pipe to the top of the radiator, where it is cooler, and starts over again. In this system, the two hose pipes at the top and bottom of the radiator should be frequently inspected, and often replaced, this being a very small expense. The gaskets at the junction of the upper and lower pipes with the cylinders, six in number in this case, should also be inspected and replaced frequently, while the small pipe shunt to the carbureter must be taken off and cleaned out at frequent intervals; it easily fills with slime and sediment.

10 represents the structural detail of the framing and fore-door. Fig. 1 is a front elevation and Fig. 12 is a plan of the work which will have to be done upon the body in the process of reconstructing the same to include the fore-doors.

The material specified is 16-gauge sheet aluminum over the

autoist to utilize the fore-doors in periods of inclement weather and to avoid the couped-in feeling during periods of calm.

Referring to Fig. 11 the dotted lines of the speed-change lever indicate how it must be bent in order that it will pass through an opening of the body to the inside at a point above the quadrant. In this car the quadrant is not only high up but falls to a considerable distance outside of the line of the chassis frame. This necessitates a rather deep cut in the body, and in order to create a somewhat better impression than would otherwise obtain, this cut may be housed over. The throw of the lever is relatively short, which is a fortunate circumstance, since it reduces the dimensions of the housing and makes it possible to consider having the side

wooden framing. The pillar to form the doorway as shown in Fig. 10 is a U-shaped bent wood piece, framed against the seat, side, front, and to the underbody. The pillar is continuous for the whole distance up the front of the door, and the metal side panel is grooved into the same, rather than to have it finished on the outside. At the bottom a horizontal framing piece is fitted in between the pillar and the dash. It is also necessary to frame the duster moulding into the pillar, when the latter is assembled to the underbody. The doors are hinged, and it is recommended that they be swung in a substantial manner, although an opportunity will be offered to select the character of hinges which will permit of detaching the doors at will; this is a modern idea, and it offers the advantage of permitting the

lever for the sliding gears fall to the inside. It is a much more convenient arrangement.

Rapid System of Finishing Bodies

Clean surface thoroughly, apply primer, work to smooth finish, sandpaper surface ending with No. O; dust off. On the third day apply opaque color, then ground-work color; when dry apply coat of glaze, rub lightly with a roll of broadcloth dipped in water, and No. OO pulverized pumice stone to kill gloss. Apply coat of elastic rubbing varnish, then rub with pumice stone and water. About the eighth day, apply coat of clear elastic rubbing varnish, slick down with pumice stone and water, wash up and finish with a rich full body varnish.