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 Cooling Oil Experience.

Editor Horseless Age:

I have read with interest the articles for and against the use of oil for cooling automobile engines in winter, and perhaps my experience with this oil may be of interest to some of your readers.

When I ﬁrst applied for an oil for cooling gas engines the local representatives of the Standard Oil Company did not seem to know of just such an oil, but said they had an oil which was used for oiling windmills and other apparatus used in the open, and which would not freeze at the lowest of temperatures. I purchased 5 gallons to try this oil (it is known as Polar Ice), and it has proven satisfactory in every way. So far this winter the temperature has been as low as 7° below zero, and with one exception the oil has never failed to cool the engine. This one instance was when the supply of cylinder lubricating oil gave out, and under such circumstances the engine would have overheated with water in the circulating system.

The machine in which this oil was used stands in a cold, unheated barn (not in a warm garage), and the oil has never failed to give good service.

It is known that oil attacks rubber hose, but when a person knows that his engine will be cooled and that his cooling medium will not freeze or evaporate. he feels that he can afford to replace leaky hose at the end of the winter months.

Gear Design Problem.

Editor :

I have read with interest the recent articles on change gear design, but ﬁnd some variation in the results of the formula of Mr. Heldt and Mr. Fay. I enclose sketch of a gear, which, we will say, necessitates the use (for constructional reasons) of a ﬁner pitch on the “countershaft gears" which are at the drive end. The faces of these gears have been deduced from a number of formula with varying results. Would like to hear Mr. Heldt's and Mr. Fay's solution of this construction, giving an equal stress per square inch on the low speed pinion when driving through low gear. That is, so that the teeth of each pinion shall be equally loaded in proportion to its face and pitch. It will be seen that the angular velocity of the countershaft pinion when driving on the intermediate speed is the same as that of the driving shaft, and when driving on low gear is just half the speed of the drive shaft. The ineffective portion of the face is to be omitted from the calculation, as the full face of the tooth can be made effective, if the teeth are beveled only on one face, leaving the driving face intact.

The engine will develop 594,000 foot pounds per minute at 950 revolutions per minute. Normal piston speed, 633 feet per minute.

[No formulae for this type of gears were given in our article on gear design, as only two of the cars the gear data of which was gathered had their gears arranged in this manner. It will be noticed, by referring back to this article, that the stress in the metal for the ﬁrst speed pinions is in each case about 28,000 pounds, while the stress for the countershaft pinions is in one case 37,000 and in the other 49-000, or an average therefore of 43,000 pounds. If you wish to use the same stress in the first speed pinion and in the countershaft pinion you will get a countershaft pinion proportionately wider and a ﬁrst speed pinion proportionately narrower than used on the two cars with this type of gear referred to in the article on gear design. An average stress of 35,000 pounds per square inch might be allowed. This would give a width of eleven-six-teenths inch for the ﬁrst speed pinion and 1 3.16 inches for the countershaft pinion. The intermediate speed pinion transmits a tangential pressure only two-thirds as great as that transmitted by the low speed pinion, but as it runs at a proportionately greater peripheral speed, the width can hardly be made less than that of the low speed pinion, viz., eleven-sixteenths inch.—.]

Wants a Side Door Body.

Editor :

Will you kindly inform me through your valuable paper, or ask some of your kind readers, whether it would be possible to convert my 1904 autocar with rear entrance tonneau body to a side entrance tonneau vehicle, without reducing the speed or otherwise injuring the car? Also about what the cost would be?

A. J. S.

[We do not believe that it is possible to ﬁt a side entrance tonneau body, as this requires at least a foot more room back of the front seat than the ordinary tonneau, and the frame is not long enough for that.—.]

Expense of Operating a Steam Runabout.

Editor :

Having read with much interest the expense accounts of different car owners in your recent issues, I thought perhaps my experiences in the expense line might interest others; here they are:

In April, 1903, I purchased a second hand steam runabout. During the summer I used it as a touring car, myself and wife making a trip to Monterey over the Santa Cruz and San Juan mountains, and side trips, 430 miles the round trip. In the late autumn we made a tour through Lake County, one of the many “Switzerlands of America," over some rough mountain roads, running in all 2,058 miles for the season.

Early this spring we toured to the "Giant Forest" in the Sequoia National Park, and return, 625 miles, and were the ﬁrst to negotiate that mountain road with an automobile. Some idea of the climb can be obtained from Geological Survey mark of 6,400 feet elevation at Camp Sierra—enough to convey the idea that we are not patrons of the park boulevards. Being a machinist by trade and occupation has reduced my expense account, I believe, very much. I have run the car 1,551 miles this year, or 3,609 miles in two seasons.

Depreciation, 15 per cent. of cost. per season, $56.25 .. $112.50 Gasoline, 420 gallons, average price $21.94. . . . . . . . . . . . . . . . . . . . . . ... 92.15 Repairs, spring, burner, chain, balls, etc. .. . . . . . - - - - . . . . . . . . . . . . . . .. 62.90 Tires, vulcanizing, inner tube, re- pair outﬁt, etc. . . . . . . . . . . . . . . . . .. 50.50 Miscellaneous supplies, lamps, horn, robe, etc. . . . . . . . . . . . . . . . . . . . . .. 16.90 Transportation, by boat, ferry. etc. 14.05 Stabling on road, alterations in stable, etc. . . . . . . . . . . . . . . . . . . . . . 18.80 Insurance, ﬁrst season, $300, 2 per cent. . . . . - . . . . . . . . . . . . . . . . . . . .. 6.00 A total cost of. . . . . . . . . . . . . .. $373.80

Or 10.35 cents per mile. Ignoring the all important factor, depreciation, the bill would be $261.30, or 7¼ cents per mile. The average mileage per gallon of gasoline was 8.35.

The following list shows a percentage of cost of the different expenses Without Depreciation Depreciation. . . . . . . . . . .30 .. . Gasoline. - - . . . . . . . . . .. .25 .35 Repair. . . . . . . . . . . . .. .17 .24 Tires. . . . . . . . . . . . . . . . . .14 .19 5tabling. . . . . . . . . . . . . . .05 .07 Miscellaneous supplies. .04 .07 Transportation .. . . . .. . ,q4 .06 Insurance. . . . . . . . . . . . .01 .02 1.00 1.00

As to present condition of car, it is A1, ready to run on ten minutes' notice.