282 



Poptdar Science Monthly 



uprights A, A, A, and are firmly toe- 

 nailed to them. They are further 

 strengthened by three pieces of iron, 

 each 6 ins. long, and i in. by 8 ins. 

 These are bent to fit the angle of the 

 outside of the uprights and the piece G, 

 and are then fastened by screws to both. 



More iron of the same size is used to 

 make the guy-wire hooks, as shown in 

 Fig. 5- Six are required to be fastened 

 to the cross-wires as indicated. Carriage 

 bolts are inserted through holes drilled 

 in the end.s, and the wires are attached 

 to these bolts. Ob\iously, the guy- 

 wires are attached before raising the 

 mast, and may be broken up by in- 

 sulators as usual. No. lo or 12 gal- 

 vanized iron wire is good for the guy- 

 wires, the lower ends of which should 

 be fastened to heavy stakes, trees or 

 "dead men." A good anchor is made 

 by burying about 3 ft. of telephone 

 pole, with a stout wire fastened around 

 it, some 3 or 4 feet deep (crosswise or 

 horizontally). The guy-wires may be 

 fastened as close as 20 ft. to the base of 

 the mast, but should be farther away if 

 space and conditions permit. 



Since the mast is rather light, a heavy 

 foundation is not necessary. A good 

 foundation can be made by digging a 

 hole somewhat larger than the mast and 

 about 2 ft. deep, and filling it with a 

 cinder or stone-concrete mixture, leveled 

 off on top. Three pieces of pine, 3 ins. 

 by 3 ins. and about l foot long, should be 

 embedded in the concrete about 6 ins., 

 forming a triangle the size of the inside 

 of the base. Wlien the mast is set 

 over these, the three uprights may be 

 nailed to them as shown in Fig. 7, thus 

 keeping the foot of the mast on the 

 foundation. 



A pulley should be attached to the 

 top of the mast by means of an eye-bolt 

 through the pole. A good half-inch 

 nianila rope is best for the halyard. 

 The rope should be twice as long as 

 the mast and siiliced to prevent its 

 pulling out at the top. This pole is 

 very stiff, if carefully constructed, and 

 may be picked up by the extreme ends 

 without bending. In raising, there 

 should be a man at each guy-wire to 

 keep the mast straight. If it is to be 

 near a building, a block-and-tackle may 

 be riggetl up 011 ihe side of (he building 



and the mast raised by hauling on the 

 top or middle. If no such conditions 

 exist, it may be pushed up with poles 

 in the way a telephone pole is handled. 

 Painting, preferably with whitelead, 

 should, of course, be completed before 

 erecting. 



The builder will find the mast much 

 easier to construct, once he gets started, 

 than he may at first imagine. The first 

 mast of this type ever built has been up 

 for some time, and has weathered se\'eral 

 hard windstorms, in spite of the fact 

 that the two guy-wires which carry the 

 strain are in a line that is not more than 

 12 ft. from the base. — C. S. Robinson. 



A Sending Condenser 



A GREAT many amateurs try to use 

 glass fruit jars of brine in a tank or 

 pan of brine but after a trial give up 

 this scheme because of the brush dis- 

 charge and the bother of frequently 

 having to replenish the water. If 

 enough automobile lubricating oil is 

 poured in to make a layer of about one- 

 half inch on top of the salt solution, the 

 evaporation and most of the brush 

 discharge will be stopped. The inside 

 brine acts as the inner coating of a 

 Leyden jar, and the salt water in which 

 the jars stand takes the place of the 

 outer coating. The drawing shows how 

 to connect for high or low \uhage. 



-7- 



Series connection 



Parallel connection 



