128 



SCIENCE. 



[Vol. XII. No. 293 



sula of Noto on the west, and the island of Sado on the east. 

 Now, it is just 4t this region that Sekino's 5° isogonic line makes a 

 great bend to the north, doubling back just over the island of Sado, 

 and then, after an easterly sweep, continuing north-easterly across 

 the country. It is extremely doubtful whether the observations 

 warrant such a delineation of 5'^ declination. A careful scrutiny 

 of Sekino's numbers brings out certain discrepancies which should 

 not altogether be neglected. Further, there is a complete lack of 

 observations along the coast to the south and south-west of Sado, 

 — just where observations seem most called for. The stations 

 chosen are all inland, and show striking irregularities in the values 

 of the declinations. True, the declinations at the three stations on 

 Sado are all considerably less than the values at mainland stations 

 immediately to the east, whereas we should expect to find them 

 greater. But that seems hardly a sufficient reason for making the 

 isogone of the form represented ; for it is well known that the iso- 

 gonic lines at and near islands often present irregularities of quite 

 a local description : hence, in default of evidence which could only 

 be obtained by a series of observations along the coast of the main 

 island, it seems more prudent to draw the isogonic line of 5" fairly 

 normal, and represent the disturbance due to Sado by a small iso- 

 lated contour round that island. In this way it is shown on the 

 map. As a matter of fact, every volcanic region is certain to pre- 

 sent magnetic irregularities, and in Japan there are two regions 

 specially to be noted as such. The one is the great central moun- 

 tainous region, just where the Fossa Magna is. The other is the 

 part between the 38th and 40th parallels, but there is nothing geo- 

 logically comparable to the Fossa Magna. In both regions a pro- 

 digious development of volcanic rocks occurs, and this is presum- 

 ably the reason for the irregularities in both regions. 



Knott does not refer to the great horizontal dislocation which 

 Naumann considers the cause of the northern irregularity. The 

 question at issue is one of great interest. Local variations are ob- 

 served in every country, even in those where no volcanic rocks 

 occur ; and the problem formulated by Naumann, which is a study 

 of the local variations of the magnetic force as connected with the 

 geological structure of the country, is well worth a thorough and 

 continued study. 



THE ELECTRIC-LIGHT CONVENTION. 



The National Electric-Light Association met in New York at 

 the Hotel Brunswick on Aug. 29, and continued in session for three 

 days. Pres. S. A. Duncan opened the convention with an interest- 

 ing address, in which he reviewed the growth of the association 

 and of the electric-light industry. When the association was first or- 

 ganized, the foreign technical papers only noticed its proceedings 

 in order to ridicule them : now the papers read at its meetings are 

 copied by the leading electrical papers all over the world. The 

 membership of the association has largely increased, as has the in- 

 terest taken in it by the members. 



The electric-lighting industry has rapidly advanced in the last 

 six months, since the meeting of the association held in Pittsburgh. 

 Then it was estimated that there were in the United States 4,000 

 isolated plants and central stations, supplying 175,000 arc lights 

 and 1,750,000 incandescents. To-day there are 5,351 isolated 

 plants and central stations operating 195,000 arc and 1,925,000 

 incandescent lamps, employing 459,495 horse-power of steam- 

 engines. The increase in the capitalization of the electric-light 

 companies in the last six months has been §42,210,100. 



Coming to the question of the distribution of power, there are at 

 present 34 electric railways completed, having 1 38 miles of track, with 

 223 motor-cars; there are in course of construction 49 other electric 

 railways, with 189 miles of track and 244 motor-cars ; giving a total 

 of 83 roads, with 327 miles of track, operating 467 motor-cars. 

 Besides these, there are 39 other electric roads incorporated which 

 have not yet begun construction. 



Mr. Duncan then urged that the association establish a permanent 

 office, which would be the headquarters of the executive committee, 

 and which should contain a good reference-library, together with 

 domestic and foreign electrical journals, and the repository of the 

 archives of the association. 



Mayor Hewitt was then introduced, and welcomed the associa- 

 tion to New York in a characteristic and eminently common-sense 

 speech. He dwelt particularly on the question of putting electric 

 wires under ground, — a subject in which New York is at present 

 especially interested. To quote one of his remarks, " I congratu- 

 late you that it [the feasibility of putting high tension wires under 

 ground] is going to be tested by a responsible company ; and until 

 it is tested, let me say to you frankly, that, if it were in my power 

 to compel the other companies to do this thing now, to-day, I 

 would not do it. . . . But I hope it will succeed ; and if it does suc- 

 ceed, no public officer will be more prompt than I shall be in com- 

 • pelling every electric-light company to respect the intention of the 

 Legislature." Again, speaking of the danger of the electric cur- 

 rents. Mayor Hewitt summed up as follows : " I found, that, with 

 all the difficulties of this thing, the absolute results seemed to show 

 that it was absolutely safer than any other useful agency at work 

 in this city." 



The various papers read before the association were hardly so 

 important as those given at the last meeting at Pittsburgh, but 

 some of them contain valuable information. The following ab- 

 stracts give the main points m each : — 



Mr. S. S. Leonard, in his paper on ' Petroleum Fuel,' said that 

 the advantages of oil over other fuels are many : it is more easily 

 regulated, there is less attendance required, the fires can be started 

 or stopped instantly, there is no refuse to cart away, it is cleaner 

 than any other fuel except natural gas. The arrangements for the 

 use of oil under the supervision of the writer are as follows : the 

 oil is received in tank-cars holding from 90 to 150 barrels each ; it 

 is then drawn off into storage-tanks holding 320 barrels. These 

 tanks are boiler-shaped, and are placed under ground end to end, 

 and are connected together. Each tank has a man-hole and vent- 

 pipe. The supply-pipes to the furnaces have valves at the tanks 

 and at the furnace. These pipes are two inches and a half in 

 diameter except about four feet at the furnace end, which is en- 

 larged, and contains a small steam-pipe, which raises the tempera- 

 ture of the oil to 130° or 140°. The experience of the writer is, 

 that the best burner for the oil is one that thoroughly vaporizes it 

 before it is burnt, steam and hot air being used with it. As to 

 economy over coal, there is a saving of from twenty to twenty-five 

 per cent in fuel, and from forty to fifty per cent in labor. From 

 tests recently made, the cost of oil was 70 cents per 100 horse- 

 power per hour ; of coal, at the rate of 86 cents per 100 horse-power 

 per hour. Another test gave the cost as 80 cents for coal and 62 

 cents for oil. As for labor, one man can attend from seven to ten 

 150-horse-power boilers, while there is no dirt or ashes to haul 

 away. 



The discussion on this paper brought out no new facts, except- 

 ing, that, in view of the repeated attempts and failures of the past, 

 there was a tendency to mistrust oil as a fuel, both as regards ex- 

 pense and the deterioration of the boilers. It was stated, however, 

 that Mr. Leonard had been using oil for nine months, and was 

 satisfied with its economy and reliability. 



Mr. S. S. Wheeler, in his paper on ' Overhead and Underground 

 Wires in New York,' reviewed the history of the Board of Electrical 

 Control, of which he is electrician, and pointed out the difficulties 

 that they had encountered in their work. Besides the fact that there 

 was no precedent to guide them, the wholesale putting under 

 ground of electrical wires never having before been attempted, the 

 local conditions were particularly unfavorable. New York being 

 built on a long, narrow island, the electric wires are crowded to- 

 gether, and the distance between points increased. The ground is 

 full of gas, water, and steam pipes, sewer and pneumatic despatch- 

 tubes, and the earth is saturated with gases. After describing a 

 number of underground systems, Mr. Wheeler gave the history of 

 the modified Dorset conduit used in New York. In the original 

 system the conduit consisted of a bundle of parallel tubular ducts 

 about two inches and a half in diameter, built of blocks made of a 

 mixture of coal-tar, pitch, and gravel, cast with tubular openings 

 running through them from end to end. These blocks were placed 

 end to end so the openings were continuous, and were cemented 

 together. The diffixulty in this system was that the blocks were 

 brittle and porous, and they would not remain water-tight. After 

 various modifications, the plan finally adopted was to use parallel 



