Frictional test of Valvoline Machine Oil, on May 5, 1880. Rev.' per minute 526.39, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 592.18 feet per minute. No. of sample 15. No. of trials 6.

Frictional test of Olney Bros. A Spindle Oil, on May 8 and 10, 1880. Rev. per minute 512.27, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 576.30 feet per minute. sample 16. No. of trials 7.

No. of

Frictional test of Aiken & Swift Unbleached Winter Sperm Oil, on May 12 and 13, 1880. Rev. per minute 495.54, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 557.48 feet per minute. No. of sample 17. No. of trials 5.

Frictional test of Aiken & Swift Bleached Winter Sperm Oil, on May 14, 1880. Rev. per minute 490.87, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 552.23 feet per minute. No. of sample 18. No. of trials 4.

TEMPER.

ATURE.

Frictional test of Downer Heavy Spindle Oil, on May 15, 1880. Rev. per minute 458.02, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 515.27 feet per minute. No. of sample 19. No. of trials 5.

Frictional test of Downer Light Spindle Oil, on May 17 and 18, 1880. Rev. per minute 489.63, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 550.83 feet per minute. No. of sample 20. No. of trials 3.

trials 5.

Frictional test of Seal, on May 19-21, 1880. Rev. per minute

467.34, 5 lbs. pressure per sq. inch.

Velocity of rubbing sur

faces 525.76 feet per minute.

No. of sample 21.

No. of

Frictional test of Alexander Boyd & Sons Neatsfoot Oil, on May 22, 1880. Rev. per minute 526.15, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 591.92 feet per minute. No. of sample 22. No. of trials 4.

Frictional test of Unknown [Mixed] Oil, on May 24, 1880. Rev. per minute 490.46, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 571.77 feet per minute. No. of sample 23. No. trials 4.

Frictional test of Unknown [Mixed] Oil, on May 24 and 25, 1880. Rev. per minute 471.86, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 530.84 feet per minute. No. of sample 24. No. of trials 4.