SCIENCE. 



[Vol XIII. No. 310- 



BALL ELECTRIC-LIGHTING SYSTEM. 



One of the most peculiar of the many dynamos that have been 

 used or proposed for arc-lighting is that of the Ball Electric Com- 

 pany. From the accompanying illustration it will be seen that two 

 armatures are mounted on the shaft, with one pole-piece for each. 



The mechanical construction of the dynamos is excellent, and, 

 from the testimonials contained in the last circular issued by the 

 company, it would seem that the machine can stand the maximum 

 of rough usage with a minimum of repair. 



Besides the high-power lamps of 2,000, 1,600, or 1,200 candle- 

 power, the Ball Company advertise smaller arc-lamps of 800 candle- 

 power, for use in stores, etc., and they also provide incandescent 

 lamps to be used on arc-light circuits. They also furnish complete 

 incandescent-light installations. 



The armatures are of the well-known Gramme ring type, and are 

 constructed with a large number of separate coils, thus reducing 

 the sparking at the commutators to a minimum. By some it is 

 claimed that the dynamo must be at a disadvantage from the 

 considerable magnetic resistance that the lines of force experience 

 in passing from pole-piece to pole-piece. By others it is said that 

 this is not so, as the lines of force do not close their circuit from 

 pole to pole, but from poles through armatures to magnet-bars 

 opposite; and that from the thinness of the copper windings, and 

 from there being two armature-cores in multiple across a common 

 field, the magnetic resistance is actually less than in other makes 



THE "IDEAL" STEAM-ENGINE. 



An improvement in one of the most important steps in the con- 

 version of heat into power, showing the results of scientific meth- 

 ods applied to the design and construction of the steam-engine, is 

 illustrated on this and the next page. This engine, which is known 

 as the " Ideal," is a more highly developed form of the Ide engine, 

 and is manufactured by A. L. Ide & Son of Sprinfield, III. It was 

 designed to meet the special requirements of electric lighting, such 

 as high speed, small space, perfect regulation, absence of vibration, 

 and economy in the use of steam ; and the results shown by actual 

 use prove that the designers of the engine are progressing in the 

 right direction. The engine is compact, perfectly balanced, and 

 self-oiling ; and, as it has a rigid double frame with heavy sub- 

 base, it may be run at a high speed without vibration. 



The manner of lubricating the guides, cross-head pin, and pis- 

 ton-rod, is shown in the longitudinal section. Fig. i. The oil is 

 taken up by the crank-pin disks, when in motion, and thrown by 

 centrifugal force upon the guides and piston-rod. The oil wiped 

 from the upper guide by the cross-head slide passes through a tube 

 in the top slide, entering a funnel in the connecting-rod, and thor- 

 oughly lubricating the cross-head pin. The peculiar manner of 

 keeping a constant supply of oil in contact with the crank-pin, 

 main bearings, and eccentric, is shown at Fig. 2. Some of the oil 

 thrown off by the revolving disks is caught in the pockets in the 

 disk-hood (Fig. i). The oil from the upper pocket is conducted by 

 a tube provided with a regulating-cock to a receptacle on the ec- 

 centric-strap, whence it passes, after lubricating the eccentric, to a 

 drip-pan underneath, and thence back to the oil-well for further 



of dynamos. The large output of the dynamo in comparison to its 

 weight, and the small amount of copper used upon its field, seem 

 to testify to the correctness of the latter. 



Its advantages, which are of a practical kind, lie in the fact 

 that by distributing the rotating wire on two armatures the number 

 of layers can be reduced, the difference of potential between adja- 

 cent turns is less, and therefore there is less liability to burn out, 

 while the excellent ventilation prevents overheating ; also, if any 

 thing happens to one armature, the other can be used to run part 

 of the lamps. 



use. The oil from the other pocket flows through pipes into pock- 

 ets cast upon the main bearings. From these points it flows into 

 the grooves and channels connecting with the crank-pin, which is 

 hollow. The centrifugal force carries it into the crank-pin, from 

 which it escapes through holes into the bearing. Thus it will be 

 seen that the main bearings receive constant lubrication, while the 

 crank-pin receives a supply of oil from either side. This method 

 of lubrication is constant, and provides for the most important 

 bearings about the engine. Sufficient oil is placed in the basin 

 under the crank-disks to cause it to flow in streams through both 



