36 



SCIENCE. 



[Vol. XV. No. 36; 



THE EDISON ELECTRIC LIGHT STATION IN 

 BROOKLYN. 



We illustrate in tiiis issue the central station of the Edison Il- 

 luminating Company recently completed in Brooklyn, N.Y. Fig. 

 I is a view of the Pearl Street front of the building, Fig. 2 is a 

 plan of the engine and boiler room, and Fig. 3 is a vertical section 

 of the station. The station is designed-for an ultimate capacity of 

 36.000 lights of 16 candle-power each. At present only about one- 

 third of the plant is installed, that being sufficient to supply the 

 immediate demands. The rest will be added as required. 



The building, which is fire-proof throughout, is seventy-four by 

 a hundred feet, three stories high, and is located practically in the 

 centre of the district to be supplied. Besides the generating plant, 

 supply rooms, store rooms, etc., the building has ample room for 

 offices, thus enabling the company to centre all departments of its 

 business under one roof. 



Under the sidewalk are located large reserve coal vaults, the 

 coal for immediate use being in a storage room on the second 

 floor, over the boiler room. On the first floor are the engine and 

 boiler rooms ; 'the dynamos and electrical apparatus generally are 

 on the second floor, and the third is taken up by store and supply 

 rooms and by a suit of handsomely fitted offices. Under the 

 engine room is a solid bed of concrete four feet thick, laid entirely 

 apart from and independent of the wall foundations. Upon this 

 rest the foundations for the twelve engines. In this manner all jar 

 from the engines is absorbed or neutralized, none of it being trans- 

 mitted to walls or floors. 



The engines are high-speed compound Ball engines, of three 

 hundred horse-power each, the high-pressure and low-pressure 

 cylinders being respectively thirteen and twenty-five inches in 

 diameter and sixteen-inch stroke of piston. These are said to be 

 the heaviest and largest engines of their class ever built. The 

 general arrangement of engines and boilers is shown in the plan. 

 Fig. 2. 



Steam is supplied by eight Babcock & Wilco.x sectional boilers 

 of the largest type, arranged in two groups or batteries of four 

 each. Each boiler has about 2,800 square feet of heating surface 

 — between six and seven square feet for each horse-power de- 

 veloped. The boiler room has all necessary arrangements for the 

 convenient working of the plant. The ash-pits under the boilers, 

 into which the ashes are raked from the furnaces, discharge into a 

 car running on a track in the basement, which is then hoisted on 

 an elevator, thus avoiding all shoveling and handling. The coal 

 is elevated to the store-room, whence it is fed down to the boilers 

 through chutes, on each of which is a special coal-scale, so that 

 every day's supply is known, and the economy of the plant is con- 

 stantly recorded. Water meters, in a similar way, record the 

 quantity of water used. Two main steam pipes extend from the 

 boilers to the engines, each engine and boiler being connected to 

 both pipes, so that any boiler or engine may be disconnected with- 

 out interfering with the operation of the others. 



The front half of the second story is devoted to the electrical 

 plant. The space is arranged for twenty-four Edison dynamos, 

 each engine being belted directly to two dynamos. The dynamos 

 run at a speed of 650 revolutions per minute, and each has a 

 normal capacity of fifteen hundred sixteen-candle power lights. In 

 both engine room and dynamo room overhead travelling cranes 

 are arranged, for the convenient handling of heavy pieces of ma- 

 chinery. 



Through the centre of the dynamo room runs what is called the 

 " electrical gallery," to which are brought all the cables from the 

 dynamos. In the centre of this gallery, within easy reaching 

 distance of one person, are arranged all dynamo swtches, dynamo 

 field-boxes, ampere meters, etc., so that one man in this gallery 

 has all the electrical apparatus under his immediate control. 



From this gallery seventeeri feeders run to different parts of the 

 district to be supplied with lights. The three-wire system being 

 used, each feeder consists of three cables, a positive, a negative, 

 and a neutral. By the arrangement of apparatus in the gallery, 

 the man in charge can see at a glance the total load on the 

 dynamos, and through what feeders and in what part of the dis- 

 trict this load is being distributed. The underground system or 



net-work of wires throughout the district is all united by large 

 mains ; and the regulation of current is such that at no time is 

 there a difference of potential of more than one volt throughout 

 the district. 



The underground system, as at present laid out, is arranged for 

 a total of twenty thousand lights, and may be readily extended as 

 the demand warrants. It covers an extreme distance of a mile 

 from the station in one direction, and about three-quarters of a 

 mile in the other, in an excellent business and residential district, 

 from an electric lighting point of view. 



The Edison system of underground tubing, which has proved so 

 successful, has been introduced here, with many improvements 

 and additions. The maximum drop under full load is one per cent 

 on the mains, and there are only four sizes of tubes used in the 

 mains, ranging respectively from 100,000 to 250,000 circular mils. 

 Mains, as here introduced, are in larger-sized tubes than have here- 

 tofore been used, allowing more insulation compound to be intro- 

 duced into the tube. All three wires in the mains are of the same 

 size. 



The Edison system of distribution is too well-known to need 

 any extended description. Service connections can be taken off at 

 the coupling boxes every twenty feet. At all street crossings are 

 placed main junction boxes with busses, into which all mains at 

 each street-crossing are brought, thereby uniting and tying the 

 mains together. at every corner, to obtain uniform distribution and 

 pressure, and to allow more readily of a proper inspection of 

 the system. At these boxes each main is protected by an ampere 

 safety catch of proper size, except the neutrals, which are coupled 

 with solid copper caiches. Into certain of these junction boxes 

 the feeders running direct from the station are connected to the 

 system of mains. In case any feeder is disconnected, for any 

 cause, it will not in any way affect the system, as the main which 

 it is directly feeding will be supplied from the other feeders. In 

 case of any accident or short circuit on the main, it does not throw 

 off the service from any customer, as the mains are fed out to the 

 point of trouble from both directions. Five of the feeders, instead 

 of running to only one point of distribution, run to a certain point, 

 and from there to two or three other points. This is to obtain 

 better control and distribution over the system. This underground 

 system, after completion and being thoroughly tested and started 

 in operation, showed an insulation resistance on the whole system 

 of over 700,000 ohms, said to be the best result in that direction 

 ever achieved in an underground system. 



THE BASIN OF THE KONGO. 



A GREAT deal of interesting information concerning the Kongo, 

 gathered from trustworthy sources, is given in the December num- 

 ber of the Scottisli. Geographical Magazine. The estuary of the 

 river, between Banana Point and Shark Point is eight miles across, 

 and soundings have indicated depths of sixty fathoms. The cur- 

 rent at the mouth is very rapid, certainly not less than three knots 

 an hour, or a little over five feet per second. Taking the vertical 

 section at the mouth to be a triangle, the base of which measures 

 eight miles and the altitude sixty fathoms, it will be found that 

 about 1,060,000 tons of water are poured into the sea per second. 

 The effect of this huge volume is perceptible as far as six degrees 

 of latitude northwards from the mouth of the river, or to a dis- 

 tance of 360 nautical miles, so that a vessel making for Banana 

 feels this formidable resistance after crossing the Equator, and its 

 speed is diminished. Sailing-vessels have often to wait for weeks 

 for a spring- tide, or a strong wind springs up, and enables them to 

 enter the river. 



Another phenomenon is the current caused by the water at the 

 edge of the stream losing its onward velocity, and being forced 

 back towards the land, where it spreads itself out along the coast. 

 The ports along this coast, such as Kabinda, Loango, etc., are 

 only roadsteads with but little shelter. Vessels have to be loaded 

 and unloaded by lighters towed by small tugs. The lighters are 

 sometimes overturned, when their cargo, if it be palm-oil, for in- 

 stance, floats, and the owners know where it will be found on the 

 shore. For example, any article that falls into the sea off Landana, 



