The last enters into the composition of some of the solid lubricating greases, and is also used as an adulterant of other oils.
The viscosity test, although of considerable importance in the examination of lubricating oils, has been shown to have very little discriminative value as a general test.
This was soon put into operation in Scotland, first with the Boghead coal or Torbanehill mineral, and later with bituminous shales, and though he had to face much litigation Young successfully employed it in the manufacture of naphtha and lubricating oils, and subsequently of illuminating oils and paraffin wax, until in 1866, after the patent had expired, he transferred his works to a limited company.
Even if the slide itself is mechanically perfect, the irregularity in the thickness of the lubricating oil between the bearing surfaces of the slide is apt to produce a variable error.
For the next ten years, however, there was a decrease, and in 1908 the output had fallen to 10,858,797 barrels, of which 6,748,676 barrels (valued at $6,861,885) was obtained in the Lima district, 4,109,935 barrels (valued at $7,315,667) from the southeast district, and 186 barrels (valued at $950), suitable for lubricating purposes, from the Mecca-Belden district in Trumbull and Lorain counties.