72
in contact with the roller marked F, the projecting points on which so far seizeit as to propel it forward to meet the rapidly revolving set of cutters marked A.Passing onwards to B, it is subjected to a second action. By C a third operationis performed, and in passing through D, a perfect form is given to the pieceof timber. Thus, while the end beyond D presents the perfect section of a
A. 3Z C D
Fig. 20.
- liiii—mri i
iiu-
Ml
iUdA
HUli'.'iiiiiiiniii
BEafi
aaiiiii
finished gutter, the other end, which has not yet passed the set of cutters at A,remains in its original square form. In fig. 22, a vertical section is given, exhi-biting the precise angle at which the cast-iron blocks are made to revolve, andthe cutters to clear away the timber before them. 0 shows the section of thegutter acted on by the cutters, N the holdfast by which the gutter is kept in itsplace during the operation. By the use of this machine three feet of gutter can bemade per minute, and, working night and day at this rate, the whole auantityrequired was completed in two months.
Fig. 22.
a* 5
The Paxton Th.c 1 axton gutters, thus prepared, were delivered on the ground, and aftercompleted for having been carefully examined, and the defective ones removed, they were con-
ground. vcyed to other machines (vide fig. 23), fixed upon the ground, by means of which
they were finished ready for use. A large circular saw, the spindle of whichcould be raised or depressed by the action of a lever, had fixed in the centre of oneof its sides two gouges, adapted to produce, by rapid revolution, a semicirculargroove. A frame, the exact length of the gutters, was fixed at right angles to the