The World's Largest Public Domain Media Search Engine
Uncle Sam istrying to find a way for automobile tires to wear longer for 25,000,000 motorists. Wearing specimens of rubber to [...] that then 25,000,000 owners of automobiles may have tires that last longer is a [...] now in progress at the Bureau of Standards. W.L. Holt of the Rubber Section is shown with a new abrasive machine that rubs [...] of rubber away or to a thinness that [...] determine their relative wearing quality

Similar

Explore more

glass negatives
glass negatives