PART THE THIRD.

ON ADJUSTMENTS.

CHAPTER I.

Arts. 447-449. General principles.

CHAPTER II.

TO ALTER THE VELOCITY RATIO BY DETERMINATE CHANGES.

Art. 450. Change-wheels; 451, fixed to the axes; 452, with idle-wheels.

453-456. Speed pullies. 457. Formula. 458. Screw-cutting lathe. 459.

Turning lathe. 460. Large lathe. 461. General principles. 462, 463. Link-

work.

CHAPTER III.

TO ALTER THE VELOCITY RATIO BY GRADUAL CHANGES.

Art. 464. General principles. 465-468. Solid pullies. 469. Expanding riggers.
470. Disk and roller. 471. Equitangential conoid. 472. Solid cam. (vide Art.
237). 473. Link-work. 474. Differential detents. 475. Saxton's differential
pully. 476. Troughton's differential foot-screw. 477. American winding stop.
478. Piles of blocks for adjustments.

PART THE FOURTH.

COMBINATIONS FOR THE ACTION OF WHICH PROPERTIES

OF FRICTION ARE EMPLOYED.

CHAPTER I.

FRICTION IN GENERAL, AND THE MODES OF DEMONSTRATING ITS PROPERTIES.

Arts. 479-483. Introduction and constants. 484. The three laws. 485. Effect

of time of contact and of vibrations, coupling link. 486. Apparatus for

exemplifying the two first laws. 487. Apparatus for exemplifying the third

law.

CHAPTER II.

EMPLOYMENT OF BUTTING FRICTION.

Art. 488. Perrault's hand. 489. Dobo's silent ratchet wheel and Worssam's
construction of it. 490. Contrivances to stop lifts and hoists when their
suspending ropes or chains break.

CHAPTER III.

EMPLOYMENT OF JAMMING OR TWISTING FRICTION.

Art. 491. The carpenter's holdfast. 492. Weston's patent clamp. 493. Rod

ratchet work for weavers. 494. Hitch-stick. 495. Dr. Hooke's contrivance

to stop great weights falling. 498. Friction of drawers.

CHAPTER IV.

EMPLOYMENT OF FRICTION WHEELS.

Art. 497. Carriage wheels and rollers placed under heavy packages. 498,

499. Friction wheels. 500. Whitworth's treadle link.

CHAPTER V.

EMPLOYMENT OF COIL-FRICTION.

Art. 501. Experimental data. 502. Example from a handloom for weaving:

friction pace. 503. Silent ratchet motion through indefinite angles; Capstan,

and surging the messenger. 504. Sir Christopher Wren's method of dispen-

sing with surging.

CHAPTER VI.

SUBSTITUTION OF WINDING COILS FOR RUBBING FRICTION.

Art. 505. Perrault's crane. 506. Moore's differential pully for raising weights.

PART THE FIFTH.

ON UNIVERSAL JOINTS

CHAPTER I.

HISTORY AND APPLICATIONS.

Art. 507. Employed for two different purposes, defined.

Examples of first purpose.

Wilars de Honecort's rolling brazier. Hooke's uninvertible carriages, &c.

Examples of second purpose.

Connection of rods by a universal joint. 1st form by Amicus, published in

1664, p. 439. 2nd form by Hooke for description of sun-dials, 1667, p. 441.

CHAPTER II.

CONSTRUCTIONAL FORMS AND THEORY.

Art. 508. Introductory remarks. 509. Simple form of Hooke's joint, and four
other forms. 510. Hooke's adjustable form for his clockwork. 511. Hooke's
machine to graduate sun-dials. 512. Constructions for sun-dials by Clavius
and Foster. 513. Velocity ratio of Hooke's joint. 514. Ratio equalised by
double joints. 515. Model to exhibit this constancy of the ratio. 516
Parallel axes rotating in opposite directions.

CHAPTER III.

UNIVERSAL FLEXURE JOINTS AND SWIVEL JOINTS.

Art. 517. Composition and resolution of two small rotations for universal

flexure joints. 518. Ditto of three for universal swivel joints. 519. Ap-

paratus to illustrate the above. 520. Joints of crustaceous animals and

insects.

LIST

OF

TECHNICAL AND NEW TERMS,

WHICH ARE DEFINED OR EXPLAINED IN THE FOLLOWING ARTICLES.