a lamp which embodied the best principles, and which was sure to prove a commercial success. He had introduced improvements in the electric machine by which the equivalent of about 90 per cent. of the power expended was returned in electricity. When he was nearly ready to give the lamp in this form to the world, he began, led partly by accident, to experiment with carbon, with results which induced him to alter his whole system and adopt a carbon instead of a metallic burner. A prominent cause for the failure of carbon burners had been the impossibility of obtaining a form of carbon sufficiently pure in substance and homogeneous and even in texture. Edison was encouraged to try new forms from obtaining a remarkably brilliant light in the vacuum by the incandescence of a piece of calcined cotton thread. He placed in the glass a thread of ordinary sewing-cotton, which had been placed in a groove between two blocks of iron and charred by long exposure in a furnace, exhausted the air, and sealed the tube. He then turned on the electrical current, and increased it until the most intense incandescence was obtained before the slight filament broke. Examining then the fragments under the microscope, he found that the fragile substance had hardened under the excessive heat, and that its surface had become smooth and glossy.

This led him into a long series of experiments with carbon. After carbonizing and testing a great variety of fibrous substances, he found that paper yielded the most satisfactory results. The burner on which he finally settled was made from Bristol cardboard in the form of a tiny horseshoe.

Strips about two inches long and an eighth of an inch wide, curved in the shape of an elongated horeshoe, are struck from a sheet of cardboard, and a number of them laid one upon another, with pieces of tissue-paper between, in an iron mold; this is tightly closed and placed in an oven, which is gradually raised to a temperature of 600 degrees; the mold is next placed in a furnace and allowed to come to a white heat, and then removed and left to cool. The carbonized paper horseshoe is then taken out with the utmost care, mounted in a diminutive glass globe, and connected with the wires. The air is then pumped out and the glass hermetically closed. The form of the lamp is a small bulb-shaped glass vacuum, globular above, with an elongated end resting upon a standard, through which the wires leading to and from the generator pass, connecting with thin platinum wires, which penetrate the thick end of the glass; to these the carbon burner is attached by clasps made from the same metal. No regulating apparatus is attached to the lamp, as the current can be regulated at the central station where the electricity is generated.

The inventor has developed a method by which the currents can be cut off from any of the lamps and the lights extinguished, without affecting the supply of electricity to those which are left burning. He proposes to supply the electricity in cities for lighting the houses and public places from stations in which a number of electric machines adequate for supplying an area of about a third of a square mile are driven by one or two powerful steam-engines. Each generator is capable of supplying about fifty burners.

THE RESUMPTION OF SPECIE

PAYMENTS

(1879)

THE "LEGAL TENDER" ISSUES OF WAR TIMES AND THE RESUMPTION ACT1

The balance in the Treasury on December 30, 1860, subject to the warrant of the Secretary, was $2,078,257. During the calendar year 1861, the net receipts of the treasury from all sources were $218,224,077.64, as against $59,217,030.19 for the previous year; but the expenditures had increased in a still greater ratio, and in January, 1862, the Treasury was unable to answer the requisitions upon it for disbursements. Additional resources to carry on the Government became imperative, but no coin was left in the country for which to sell a loan. Of the depreciated bank currency there was believed to be then in existence only about $150,000,000, and this with the $60,000,000 of Treasury notes made the entire circulation of the country only $210,000,000; and to collect these notes together for public disbursement, scattered as they were throughout the country, would be almost as hopeless a task as to issue a loan for coin and bring back to the country the metallic currency which had gone abroad to pay foreign indebtedness.

1 From an article in Appleton's "Annual Cyclopedia" for 1879. By permission of D. Appleton & Company.

To meet this emergency, and with a view of utilizing all the resources of the country, Congress, by act approved February 25, 1862, authorized the issue of $150,000,000 of notes, not bearing interest, payable at the Treasury of the United States, and of such denominations as the Secretary of the Treasury might deem expedient, not less than five dollars each. Of this amount $60,000,000 were for the redemption of the notes of July 17 and August 5, 1861.

Later in the same session, by act approved March 17, 1862, Congress declared the outstanding notes of July 17 and February 12, 1862, to be a legal tender in like manner, for the same purposes and to the same extent, as the notes authorized by the act of February 25, 1862. Still later, by act of July 11, 1862, Congress authorized an additional issue of $150,000,000 of notes of similar character, and, like those already issued, exchangeable for bonds; and also provided that the Secretary might receive and cancel any notes heretofore issued, and in lieu thereof issue an equal amount of notes authorized by this act. The act also provided that not less than $50,000,000 of these notes should be reserved for the payment of certain deposits, to be used only when, in the judgment of the Secretary of the Treasury, the same or any part thereof might be needed for that purpose. By act of July 17th following Congress authorized the issue of postage and revenue stamps for use as fractional currency, preferring this expedient to metallic coins or tokens reduced in value below the existing standard, making them receivable in payment of all dues to the United States under five dollars, and

exchangeable for United States notes when presented in sums of not less than five dollars.

Under these several acts a total circulation of $250,000,000 could be issued, and in an improbable contingency $50,000,000 more; also a supply of fractional currency. These issues, together with the issues of bonds, relieved the Treasury from its embarrassment, and on the 1st of July, 1862, not a requisition upon the Treasury from any department remained unhonored.

The military reverses of June, July, and August of that year, however, injuriously affected the financial condition of the country, and Congress, by act of March 3, 1863, authorized, among other measures, an additional issue of $150,000,000 of notes having substantially the same qualities and restrictions as those theretofore issued, and provided that in lieu of any other United State notes returned to the Treasury and destroyed there might be issued an equal amount of notes authorized by this act. It also provided that holders of United States notes, issued under and by virtue of the several acts heretofore cited, must present them for the purpose of exchanging them for bonds on or before the 1st day of July, 1863, and that thereafter the right to thus exchange them should cease and determine. The same act also provided that in lieu of the postage and revenue, stamps authorized for use as fractional currency, commonly called postal currency, there might be issued fractional notes of like amounts and in such form as might be deemed expedient; the whole amount of fractional currency issued, including postage and revenue stamps, not to exceed $50,000,000. Under these