expansion is double, and that of cubical expansion three times, the coefficient of linear expansion.

For example, a 60-ft. steel rail in warming from 20° F. below zero to 100° F. will expand 120.00000599×60×12 =.5175 in. in length.

735 1,060 1,440 1,875 2,380
881 1,270 1,728 2,250 2,855
7 1,028 1,480 2,016 2,625 3,330
8 1,175 1,690 2,304 3,000 3,805
9 1,322 1,900 2,592 3,375 4,280
10 1 469 2,110 2,880 3,750 4,775
11 1,616 2,320 3,168 4,125 5,250
12 1,762 2,530 3,456 4,500 5,705
13 1,909 2,740 3,744 4,875 6,180
14 2,056 2,950 4,032 5,250 6,655
15 2,203 3,160 4,320 5,625 7,130
16 2,356 3,370 4,608 6,000 7,605

17 2,497 3,580 4,896 6,375 8,080

Capacity in Gallons

3,510
4,095

2,925 4,237 5,765 7,520 9,516 11,750 14,215 16,918 18,358
5,084 6,918 9,024 11,419 14,100 17,059 20,302 22,030
5,931 8,071 10,528 13,322 16,450 19,902 23,680 25,701
4,680 6,778 9,224 12,032 15,225 18,800 22,745 27,070 29,372
5,265 7,625 10,377 13,536 17,128 21,150 25,538 30,454 33,043
5,850 8,472 11,530 15,040 19,031 23,500 28,431 33,838 36,714
6,435 9,319 12,683 16,544 20,934 25,850 31,274 37,222 40,385
7,020 10,166 13,836 18,048 22,837 28,200 34,117 40,606 44,056

7,605 11,013 14,989 19,552 24,740 30,550 36,960 43,900 47,727
8,190 11,860 16,142 21,056 26,643 32,900 39,803 47,374 51,398
8,775 12,707 17,295 22,260 28,546 35,250 42,646 50,758 55,069
9,360 13,554 18,448 24,064 30,449 37,600 45,489 54,142 58,740

9,945 14,401| 19,601 25,568 32,352 39,950 48,332 57,520 62,411
18 2,644 3,790 5,184 6,750 8,535 10,530 15,248 20,754 27,072 34,255 42,300 51,175 60,910 66,082
19 2,791 4,000 5,472 7,125 9,010 11,115 16,095 21,907 28,570 36,158 44,650 54,018 64,294 69,753
20 2,938 4,210 5,760 7,500 9,490 11,700 16,942 23,060 30,080 38,062 47,000 56,861 67,678 73,424

2

For tanks that are tapering measure the diameter four-tenths of the depth from the large end.

Drills.-Common forms of drills used in machine-shop work are shown herewith. Fig. 1 is a flat drill; Fig. 2, two forms of

Drill Shanks.-In Fig. 10 are shown two forms of straight shanks for drills Fig. 11, shows the taper, or self-centering, shank; Fig. 12 illustrates a double-tang shank.

о

FIG. 10

FIG. 11

FIG. 12

Sockets or Collets.-In Fig. 13 is shown a taper socket; Fig. 14, a double-tang socket for holding either single- or doubletang drill shanks; Fig. 15, a socket for a taper-shank drill

and a straight spindle; Fig. 16, a grip socket; Fig. 17 (a) and (b), an outside and a part sectional view of an oil-feeding socket the oil tube being attached at a.

Drills for Square Holes.-In Fig. 18 is shown a drill for a square hole with rounded corners. A round hole whose diameter is slightly less than the side of the square is first drilled. Drills are also made for hexagonal holes.

Multiple Drilling Head.-In Fig. 19 is shown a non-adjustable multiple drilling head. Where the spacing of the holes must be changed the adjustable type is used.

Chuck for Straight-Shank Drills.-A chuck for holding drills with straight shanks is shown in Fig. 20. Its jaws are operated by a square-ended key set by hand in the hub of the pinion, which in turn revolves the circular rack and moves the three tapered jaws in or out, as required.

Twist-Drill Sizes.-The sizes of twist drills ranging from .0135 in. to .2280 in. in diameter are designated by numbers; beyond the numbered sizes are the letter sizes from A to Z. Twist drills are also listed in fractional sizes beginning at in. and including 3 in., for straight and taper shanks. Tapershank drills advance from 3 in. to 5 in., inclusive, by sixteenths and from 5 in. to 6 in. by eighths. The size and diameter of