Frictional test of Leonard & Ellis White Spindle Oil, on April 23,

24 and 26, 1880. Rev. per min. 485.46, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 546.15 feet per minute. No. of sample 11. No. of trials 5.

Frictional test of Valvoline White Loom Oil, on April 26, 1880.

Rev. per minute 512.51, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 576.59 feet per minute. No. of sample 12.

No. of trials 2.

Frictional test of Olney Bros. German Spindle Oil, on April 30, and May 1, 1880. Rev. per min. 481.41, 5 lbs. pressure per sq.

Velocity of rubbing surfaces 541.59 feet per minute. No. of sample 13. No. of trials 6.

inch.

Frictional test of Downer Ileavy Spindle Oil, on May 1 and 3, 1880.

Rev. per minute 498.56, 5 lbs. pressure per sq. inch. Velocity of rubbing surfaces 560.88 feet per minute. No. of sample 14. No. of trials 5.

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. No. of sample 16. No. of trials 7.

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 & Swist Bleached Winter Sperm Oil, on

May 14, 1880. Rev. per minute 490.87, 5 lbs. pressure per sq. inoh. Velocity of rubbing surfaces 552.23 feet per minute. No. of sample 18. No. of trials 4.

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.