NT, \KT1C I] \STI5OlEVrS. 381 



and long* lines, with short and long spaces forming the 

 letters, between which a short space is used, a longer 

 space between words, and still longer between sentences. 



Price $7.50. 



Fig. 798. 



Magnetic Beam Engine. (Fig. 798.) In this simple 

 arrangement of the beam-engine, there is an electro-mag- 

 net with its poles upward, securely bolted to a mahogany 

 base, the magnet being wound with a double coil of in- 

 sulated copper wire, the ends passing through the base to 

 the under side, one of them being soldered to one of the 

 screw cups for connection with the battery. Over the 

 poles of the electro-magnet is an armature, of soft iron, 

 which is attached to one end of a walking-beam, support- 

 ed on a stout vertical brass column, branched at the upper 

 part for the reception of the beam. At the other end of 

 the beam, is attached, by a moveable joint, a connecting- 

 rod, working the crank of a fly-wheel, which is supported 

 on two brass pillars ; on the axis of the fly-wheel, there is 

 a silver break-piece, by which the battery current may 

 be interrupted, and renewed, alternately, by means of a 

 spring alternately in contact, as the axis moves round, 

 one end of the spring having contact with the break, 

 when the armature is to be brought down, but otherwise 

 free ; the other end of the spring passes through the ma- 

 hogany base, and is soldered to one of the wires from the 

 electro-magnet, the break on the axis having contact by 



