University of Virginia Library

How Lightness Is Secured.

Thus far foreign manufacturers are ahead of Americans in the production of light-weight aerial motors, as is evidenced by the Gnome and Farcot engines, both of which are of French make. Extreme lightness is made possible by the use of fine, specially prepared steel for the cylinders, thus permitting them to be much thinner than if ordinary forms of steel were used. Another big saving in weight is made by substituting what are known as "auto lubricating" alloys for bearings. These alloys are made of a combination of aluminum and magnesium.

Still further gains are made in the use of alloy steel tubing instead of solid rods, and also by the paring away of material wherever it can be done without sacrificing strength. This plan, with the exclusive use of the best

grades of steel, regardless of cost, makes possible a marked reduction in weight.