Michael Sol Collection

May 22, 1909 ELECTRICAL REVIEW AND WESTERN ELECTRIC~ 933

not desirable to open a circuit immedi­ately, for example, an overload of veryshort duration on an important feedermight not be harmful, and yet be decid­edly dangerous if of a few seconds' dura-

FIG. 200.-HIGH-TENSION OIL CIRCUIT­BREAKER, SHOWING OIL TANK

AND CONTACTS.

tion. The bellows type of relay, a dia­gram of which is shown in Fig. 201, is de­signed to control an oil switch in thismanner. The bellows is at the top andwhen the iron core of the solenoid is actu-

FIG. 201.-TI~fE-LIMITOVER­LOAD RELAY.

ated by the coil it can move but slowlybecause of the slow escape of the air fromthe bellows. As the solenoid is drawn inthe bellows moves upward and the operat­ing-circuit terminals below it are closed.

The inverse time-limit relay is so ar-

ranged that the retarding action varie~

inversely with the current flowing, so thatthe greater the current the quicker therelay will respond. Relays are also madethat open the switches when the line cur­rent, or one phase of it, reverses. Theuse of various kinds of relays permits theuse of simple oil switches that may beopened at will or automatically undervarious abnormal conditions.

Switchboard design.-The design of aswitchboard is a problem to be workedout for each installation. 1.'here are manyitems to consider and a wide range of se­lection as to instruments and methods ofconnection. Among the desirable featuresto be observed in laying out a switchboardare: Accessibility of all parts, fireproofconstruction, keeping live parts from thefront of the board, simple and "foolproof"arrangement of circuits, provision ofabundant protective devices, as well as in­dicating and recording instruments forproper operation of the units and for re­cording their output. :Many of thesepoints have been touched on already.

The multitudinous pOBsible arrange­ments of circuits, switches and instru­ments in a switchboard is a subject verylarge in itself and beyond the scope ofthis series of articles, which have at­tenlpted to give only an outline of thegeneral principles involved in the gent:'ra­tion and utilization of the alternating-cur­rents most commonly employed at thepresent time.

[THE END.]

---.•.---Lights Controlled by Wireless.

The recent Omaha Electrical Show waslighted through wireless telegraphy dur­ing one evening, the first time that alarge lighting current has been controlledwithout wires. The system is a discoveryof Dr. Frederick Millener, wireless expertof the Union Pacific.

Four thousand incandescent electriclamps were controlled from a wireless tele­graph station at Fort Omaha, five milesfrom the building. A dozen times duringthe evening Dr. Frederick :Millener turnedon and turned off every light in the bigbuilding from his station.

The current, as sent out from the Gov­ernment wireless station at the fort, waspicked up by the antennm on the roof ofthe Electrical Building. From this itpassed to a coherer, which in turn set thecurrent to energizing a four-ohm trackrelay. This relay closed a circuit solenoidswitch, thereby turning on a seventy-fivehorsepower current and the lights flashedon.

Electrification of Railways.The question of the further electrifica­

tion of the New Haven Railroad is receiv­ing the earnest attention of the officials.The electrification of the New Haven fromthe Harlem River to Stamford, Conn.,cost $5,000,000 in round figures, and theoperation has been sufficiently successfulto warrant an extension of the service.

It is now planned to increase the instal­lation for passenger traffic from Stam­ford to New Haven, a distance of thirty­nine miles; also to increase the installa­tion to provide for the electric operationof freight trains between New Haven andthe Harlem River, as well as the electricalequipment of the branch running betweenNew Rochelle and the Harlem River forboth freight and passengers.

The total cost of such additional instal­lation is placed by electrical engineers atabout $12,000,000.

The question of the saving in operatingcosts of electricity, compared with steam,is still a debatable one, though the bestestimates would indicate a saving in favorof electricity equal to between four percent and five per cent on the total cost ofinstallation of $17,000,000, this latter fig­ure including the cost of the present in­stallation between Harlem River andStamford.

This saving alone might not justifysuch a large expenditure were there ~o

other factors to be considered, such as in­creased business, ability to handle a largerbusiness to better advantage and the gen­eral convenience of not only the travelingpublic, but the general public as well, byreason of the absence of dirt, smoke andexcessive noise.

---.•.--­A Broad Charter.

Last week a charter to operate a neigh­borhood line was granted the EffinghamTelegraph and Telephone Company ofEffingham, Ga. Occasion was taken inthe charter application to reserve theprivilege of establishing a continentalsystem of telephones. The incorporatorsask that they not only be authorized toinstall a local system, but be given theright to extend it into all the towns,cities and counties of Georgia and intoall the cities, towns and counties of allthe other states or territories of theV"nited States, including the Districtof Columbia. The capitalization is $5,­000.

It is understood that the company docsnot intend doing a cable business, or"island possessions" would have been in­cluded in its field of possible operation.