SUPPLEMENT. 7 



bottom of the box, but, for convenience, it is permanently attached to the 

 steel bed. The outside dimensions of the box. when it is made of heavy 

 stuff, are as follows: length, 4 feet 5 inches; breadth, 1 foot 8 inches; 

 height, 3 feet. In this space are stowed such conveniences as the steam- 

 engine, tightening-pulley. accumulator, dynamometer, governor, swivel- 

 pulley, auxiliary brake, etc. 1 



The bea is well shown in the several figures of Plates 42 and 43. It is 

 composed of two skeleton frames of steel, hinged together by bolts. The 

 steel bed does away with the warping sometimes experienced willi the 

 wooden bed when exposed to a hot sun. Warping of the bed throws the 

 standards of the reel out of alignment, which makes the axle of the reel 

 bind in its bearings. 



The engine does not differ essentially from that shown on Plate 18, 

 with the exception of being vertical instead of inclined. 2 



The tightening-pulley' :! A collar, sliding on the vertical shaft shown in 

 the plates, has a stud on one side which forms the axle for the pulley. 

 The tension on the belt is maintained by the elastic pressure of a spiral 

 spring. Along the shaft are bored holes at regular intervals, into any one 

 of which the pin shown near the top of the shaft may be inserted accord- 

 ing to the amount of pressure which it is desired the spring shall exert. 

 When the tightening-pulley is not in use the shaft is turned on its axis, 

 carrying the pulley to the left side of the machine, giving place for the 

 standing part of the friction-line, or the spring scales — Fig. 2, Plate 42. 

 and Figs. 1 and 2, Plate 43. A pin at the foot of the shaft keeps the latter 

 from turning when it should remain immovable. 



The outriggers are of cast-steel; each is fastened or hinged to the bed 

 by a bolt going through a longitudinal slot in the outrigger. 4 In use the 

 inner ends of the outriggers rest upon studs projecting from the bed. 



The auxiliary brake ana its use. — The brake is a lever of the first order, 

 pivoted on a block screwed to the board shown on the plates. The end 

 of the lower arm. which is fitted with a wedge-shaped piece of wood, may 

 be pressed into the V-groove of the reel by force applied to the other arm, 



1 Comp. p. 07, 2 and 3. 2 Page 87, H '2. 3 Comp. p. 8G, H :t. *Corap. Plates 8 and V>. 



