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RESULTS of an experimental study of the viscosity characteristics of motor oils at low temperatures and their influence upon cranking torque and circulation within the engine are presented by the authors. At temperatures in the neighborhood of 0 deg. fahr., even oils of asphaltic origin appear to possess some plastic characteristics, while those of the mixed and paraffin-base types deviate widely from the generally accepted laws of viscous flow. Oils of these latter classes have apparent viscosities which tend to increase with decreasing shearing-stress and to become somewhat greater than might be expected from a study of their characteristics at normal temperatures. However, as resistance to cranking the engine is due mainly to oil in thin films on the cylinder walls, the relatively small temperature-viscosity coefficient of the wax-bearing oils gives them a marked advantage over those of asphaltic origin, an advantage which becomes greater as the temperature is lowered.

ONE method employed in a fundamental investigation of the composition of lubricating oils as it affects the viscosity characteristics has involved the synthesis of viscous oils by polymerizing a wide range of olefins with a condensing agent, such as aluminum chloride. Many thousand gallons of synthetic lubricating oils have been made within the last two or three years from olefins produced by cracking paraffin waxes. Details of the process have been published previously and hence are not included. The present paper deals with the characteristics of two such oils that have been synthesized in commercial quantities. The raw materials and the process of manufacture make these more expensive than ordinary motor oils, but their temperature-viscosity characteristics make them desirable for use in transmission and steering mechanisms and in hydraulic shock-absorbers, as they are less susceptible than the usual oil to viscosity changes with changes of temperature.

THIS paper represents an attempt to appraise the general automotive-fuel situation from the viewpoint of its relation to farm-tractor fuels. In particular, the probable effects of demands for fuels other than gasoline upon costs of production and distribution have been tied-in with engine operation and maintenance costs for the purpose of indicating the most logical course for fuel and engine development. In general, the farm-tractor fuel-problem is a very important one from the viewpoint of the tractor user, due to the fact that, as farm tractors are generally used, fuel is a major cost-item amounting to more than one-third of the total cost of operation of the tractor. In spite of the fact that many other considerations logically outweigh fuel costs in importance-particularly availability of the equipment and its capacity during the seasons of peak demand-this item continues to be one which is scutinized most carefully by the user and emphasized in tractor sales.

RECENT active interest in the use of commercial butane gas as a fuel for highway-transportation equipment, particularly on the Pacific Coast, indicated to Mr. Barnard the advisability of resurveying the field of possible substitutes for gasoline, especially as regards butane. Since rapid developments in the conversion of truck fleets to use butane as fuel took place in the West, Mr. Barnard considers the possibility of the general use of butane in this class of service. After going into detail regarding the chemical properties and performances of butane and gasoline, as well as their economic aspects, Mr. Barnard concludes that an attempt to supply butane under the conditions necessary for highway units eventually would result in a final cost to the operator-on a gallonage basis-higher than that prevailing for regular gasoline. He states that no very widespread use of butane as a fuel could occur without increasing the demand to a status at which the cost would be prohibitive.