292 



SCIENCE. 



[Vol. XIII. No. 324 



THE LOOMIS ELECTRIC-LIGHT SYSTEM. 



The Loomis system of electric lighting, though comparatively 

 new, has been long enough in operation to test the value of the 

 various features peculiar to it, and it has received the indorsement 

 of many establishments in which it is in use. The field in which it 



watch either the dynamo or a resistance-box. Moreover, no spark- 

 ing at the brushes can be detected when the lights are turned on 

 or off. 



The self-regulation of the dynamo, which is not obtained by a 

 waste of power in driving the current through resistance coils or in 

 weakening the current by shifting the brushes from the point of 



-DOUBLE-POLE SWITCH. 



is best known extends through the Eastern and Northern States, 

 from Maine to Michigan. 



One feature of the Loomis system is that the regulation of the 

 dynamo is automatic ; that is, that the dynamo " requires no more 

 attention than a line of shafting." So long as the power is sup- 

 plied and the bearings of the armature-shaft properly lubricated, 

 the required amount of current is supplied, and no more, whether 



there be only one lamp in circuit or the maximum number for 

 which the machine is intended. The quantity of current is dimin- 

 ished as the lamps are extinguished, and increased as they are 

 lighted, without any attention being paid to the dynamo, and it is 

 claimed that power absorbed by the dynamo is in proportion to the 

 number of lamps in actual use. The regulation of the dynamo so 

 as to secure these results is accomplished by a simple method. 

 There is no shifting of the brushes required, nor is any resistance 

 introduced into the circuit, so there is no attendant required to 



greatest efficiency, enables the lamps to be kept up to their max- 

 imum of brilliancy at a minimum consumption of power, while it 

 is believed that the steadiness of the current extends the life of the 

 lamp to its utmost limit. 



The main advantages claimed by this system may be summed 

 up as follows : first, economy in cost of plant, owing to simplicity 

 of construction of dynamos and accessories, and ease of installa- 

 tion ; second, economy of maintenance, power being used only in 

 proportion to the amount of light furnished, and no extra attendant 

 being required ; third, exemption from the necessity of stoppage 

 for repairs, as it is maintained that the armature cannot be burned 

 out under any circumstances ; fourth, the li.ght is steady ; fifth, 

 owing to absence of variation in the intensity of current, the lamp 

 lasts longer than in systems where such conditions do not prevail. 



The company maintains that the lamps are practically the only 

 destructible parts of their system, and they guarantee them an 

 average life of at least six hundred hours. They have on record 

 one case in which 42 lamps in an installation of 123 are always 

 lighted whenever the dynamo is in operation. Of these 42, 34 

 were still in use after 2,162 hours' service. Of this same installa- 

 tion, which is in a paper-mill at Holyoke, Mass., the treasurer of 

 the paper company says, " I fin9 I can cut out 122 of 123 lamps 

 without increasing the brilliancy of the remaining one or causing 

 any spark to form at the brushes." 



The Loomis dynamo is shown in Fig. i ; the lamp and socket, in 

 Fig. 2, the sockets being of such a design as to guard against 

 liability to short-circuiting. Fig. 2 shows the actual size of a 16- 

 candle-power lamp. Fig. 3 is a fusible cut-out. It has ample 

 contact surfaces for the fuses, and consequently is not liable to 

 give trouble by unnecessarily burning out. The switches, both 

 double-pole and single-pole, have large contact surfaces, and make 

 the break instantaneously. The double-pole switch is shown in 

 Fig. 4. This company furnishes ammeters, voltmeters, ground 

 detectors, and other electrical appliances and safety apparatus re- 

 quired for incandescent plants. The voltmeter is shown in Fig. 5. 

 At an early date they will have ready a motor embodying the same 

 general features as their dynamo. 



A CAVE of unexplored dimensions, containing a beautiful lake, 

 the shores of which are covered with human bones and pieces of 

 pottery, was discovered recently by two miners near El Paso, Tex. 



