382 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



means of a wire beneath the base, with a screw-cup for 

 connection with the battery current. The cylindrical pot 

 battery (Fig. 391) is of sufficient power to work this en- 

 gine with ease and rapidity, drawing the armature down 

 to the poles of the magnet with considerable power, being 

 attracted till it touches them, when the connection is in- 

 terrupted by the break-piece and spring ; but the momen- 

 tum of the fly-wheel carries the crank round, and the 

 armature is raised to be again attracted by renewal of 

 the contact the arrangement of the break-piece being 

 such that the current is interrupted while the armature is 

 receding, but passes while the armature is drawn down, 

 producing a continued and rapid motion of the beam and 

 fly-wheel. Size, 10 inches long, by 8 inches high. 



Price $9.00. 



793 - Axial Wheel Engine. (Fig. 



799.) In this engine two hel- 

 ices of insulated copper- wire, 

 at a convenient, distance apart, 

 are clamped and fastened by 

 screws to the sides of two 

 brass pillars, which are fixed 

 in a neat turned wooden base. 

 At the top of these pillars 

 there is an axis, with crank 

 and fly-wheel, the crank work- 

 ing a rod, and supporting with- 

 in the upper part of the hel- 

 ices a bent rod of soft iron, an 

 armature of the same shape 

 and size, entering within the 

 helices at the lower end, is 

 fastened to the base of the 

 instrument. One end of the 

 wire forming the helices is connected with one of the 

 screw-cups, on the base of the instrument, for receiving the 

 battery-current, the other end, of the wire of the helix, be- 

 ing in connection with a break-piece on the axle of the 

 fly-wheel, and having a spring acting against it, so that 

 the battery-current is alternately made and broken by the 

 spring being in contact, or not ; this spring is connected 

 by a wire, beneath the base, to the other cup, for the 



