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TRACT 36.

THE WHIRLING-MACHINE.

189

the medium ratio would be near 2‘3 to 1.—After all, it is tobe observed, that the numbers in the preceding table denote,not the true measure of the resistances, but only the weightsacting at the circumference of the barrel or axis, while thereal resistance of the air acts on the body at the extremityof the arm. To obtain the true resistances then, those num-bers must be all divided by the ratios of the correspondingradii or distances at which the weight and the resistance act,viz, by S0’2 for the small hemisphere, and by 51-1 for allthe other figures, as determined on the 2nd day of May;this being done, the true measure of the resistances will beas in the table below, for all the velocities from 3 to 20 feetper second of time.

42. Table of the true Resistances to the Figures in Ounces.

Veloe.

Cone.

Wh jle

Cy!in-

Hemis

fliere.

Small

li.dex of"lie powerif the ve-locity.

per

sec.

Vertex

Base

glub.-

der

flat

round

Hemis.

ilat

feet

oz

oz

OZ

. oz

oz

oz

oz

3

•028

•064

•027

.•050

•051

■020

•028

4

•048

T09

•047

•090

•096

•039

•04 s

5

•071

•162

•068

•143

•148

•063

•072

6

•098

■225

•094

•205

•21 I

■092

•103

7

•129

•298

•125

■278

•284

T23

•141

8

•168

•382

•162

•360

•368

•160

•184

9

•211

•478

•205

'456

•464

•199

•233

10

•260

•587

•255

'565

•573

•242

•287

11

•31.5

•712

•310

•688

•698

•297

•349

2-049

12

•376

•850

•370

•826

•836

■347

•418

2-042

13

•440

1-000

•435

•979

■988

•409

•492

2-036

14

•512

1'166

•505

T145

1-154

•478

•573

2-031

IS

•589

1-346

•581

1 ’327

1-336

•552

•661

2-031

16

•673

1-546

■663

1-526

1-538

•634

•754

2-033

17

•762

1 '768

•752

1-745

1-757

•722

■853

2-038

18

'858

2-002

•84S

1-986

1-998

•818

•9 59

2-044

19

•959

2'260

•949

2-246

2-258

•922

1-073

2-047

20

1-069

2'540

1-057

2-528

2-542

1-033

1-196

2'051

Propor.

Numb.

126

291

124

285

288

119

140

' V

O

9