FTL Design
History of Technology

Weston Electrical Instrument Corporation

In 1884, Weston exhibited at the International Electrical Exposition, Philadelphia.  Reproduced here is the report of the exhibit from Scientific American for November 8, 1884.  The illustrations in the text are from the article, and are linked to higher resolution images.
lab1.jpg (133798 bytes)

In an exposition where apparatus connected with electric lighting occupied so important a place as it did in Philadelphia, it was meet that one to whom that branch of electric science owes so much should be represented by his work. Few persons save those immediately interested in the subject were aware how important a part Edward Weston had played in the electric lighting field until they examined this exhibit. For Weston, to his credit be it said, has been content to work silently in his Newark laboratory, and leave to others the pleasing duty of announcing from time to time the results of his investigations in the field of applied science. Perhaps no other man has of late years accomplished so much with so little display as Edward Weston; and his work, after standing the test of long and continuous use in the field, has been found to possess even more merit than he claimed for it when first introduced. The Weston exhibit was in the northern part of the main hall, and contained that which at the same time pleased the eye of the casual visitor and attracted the serious attention of the scientist. Facing the thoroughfare on the south, a sheet of water fell upon a mass of crystal rocks, concealed in the crevices of which a score of incandescence lamps lay hid that threw back with undiminished intensity the dazzling glow of similar lamps springing from the lilies and ferns growing upon either bank. Few of the thousands that daily visited the halls of the exposition had ever seen lights glowing under water before, and the passages about the Weston exhibit were therefore frequently crowded with admiring spectators. Even in the arrangement of this waterfall could the careful and original work of Edward Weston be seen. The fountain in the center of the great ball was a ponderous affair; in fact, an ordinary spouting of water illuminated by electric lights in much the same manner as were those at the Munich and Paris expositions. But the mechanism which controlled the waterfall of the Weston exhibit was contrived with such nicety that, even near by, it looked like a huge mirror, curving outward; for the sheet of water seemed never for an instant to vary in dimensions, and was never broken. Yet seven hundred gallons of water fell every minute, coming from a centrifugal pump which in turn was coupled to a Weston electric motor.

On either side of the waterfall were groups of arc and incandescence lamps of the Weston type, and which have served to make the name of the United States Electric Lighting Company so well and favorably known.

It was a pardonable pride that induced Weston to exhibit these lamps in all the many varieties, for each type has scored a very decided success in the field for which it was designed. The arc lights stood what might be called a competitive examination not long since before the trustees of the Brooklyn Bridge; all the best known arc lamps in use being examined at the same time.

In two long rows they now stretch across the East River from New York. to Brooklyn. The Weston incandescence lamps are made both large and small, and, as shown in the exhibit glowing from many-colored globes, are pleasing to the eye, constant, and diffusive. They are improvements on the Maxim type, which heretofore was used by the United States Electric Lighting Company. What is most remarkable about these incandescence lamps is that they have been shown to have an average life of more than two thousand hours, which, in the dwelling house, where artificial light is required, on an average, five hours per diem the year round, would permit of their being left undisturbed and without renewal for the entire year.

lab3.jpg (118534 bytes)

Weston Lamps

The large incandescence lamps in the exhibit were from 125 to 130 candle power, there being about 16 candle power of intensity in an ordinary five foot gas burner when new, and about eight or ten when long in use. The circuits of these were so arranged that they could be fed at long distances from the generators with the same size conductors as are commonly used in the arc light system. There is by no means so much loss of current while in transitu when these large incandescence lights are used as is the case with the smaller lamps, and the lights may, at the same time, be more widely distributed. These, as well as the small incandescence lights, may be used or turned down without in any way affecting the generating machine or the other lights, and a corresponding change is immediately discoverable in the current generated as well as in the power used.


lab4.jpg (110309 bytes)

Mercury Pumps

The electric motor, as designed by Weston for use in the shop, was exhibited both at rest and in motion. For the latter exhibit the interior of a shop was shown, the tools being operated by the Weston motor, which ran rapidly, smoothly, and noiselessly. The electrometer, designed by Weston, while not as a whole novel, has interesting features, and is especially fitted for measuring the currents generated by the Weston dynamo. The system of lamp manufacture designed by Weston was practically exhibited from the hydrocarbon process for making the filaments to the treatment of the lamps at the mercury pumps.

One of the most interesting features of the Weston exhibit was what might not inappropriately be called the historical section, wherein were contained the various crude devices and mechanisms, the continued improvement of which finally led to the perfect lamps, switchboards, and like contrivances. The progress made by the inventor may thus be traced step by step, difficulty after difficulty is seen to have been met and mastered, until what seemed but a crude conception, and gave little hope from a practical standpoint, is observed to have gradually been reduced to a simple, smooth working, and efficient apparatus.

lab6.jpg (315213 bytes)

Historical Apparatus Display

That part of the Weston exhibit which was designed to represent his system for central stations naturally attracted much attention. It contained three engines, together having an accumulated capacity of 250 horse power. There was a group of dynamos which fed about 1,500 lamps, scattered throughout the main hall, comprising 65 arc lights, 150 incandescence lights, each of 125 candle power, and 1,275 lamps of 16 candle power.

The circuits from the dynamos and from the outside lines were all brought to a switchboard, by means of which the dynamos were coupled together as desired. By this any of the outside circuits could be coupled up or coupled to any of the dynamos, and rapidly changed from one battery of dynamos to another; the others meantime not being appreciably affected. By means of the Weston switchboard the dynamos could be connected with either of the three engines. The wires leading to the switchboard were carefully protected, as in the large central stations which have been established in New York City and elsewhere by the United States Electric Lighting Company, which, as said before, uses the Weston patents. Any combination can be made by means of this switchboard with any combinations of machines, and by means of cables the circuits are connected with the machines. A plug on either end of the cables serves, the one end to connect with the circuits, the other with the machines. In order to prevent lightning from reaching the dynamos during thunder storms, lightning arresters are affixed to each circuit. From the switchboard the circuits are extended, and so arranged that the lamps may be adjusted to each circuit. It does not injure the outside circuit when these lamps are either placed in position or removed. All the lamps are tested upon the circuit upon which they are to be used before being regularly adjusted on the line.

The types of dynamo machines exhibited for the arc and incandescence systems, as devised by Weston, do not materially differ, save in the winding of the armature and field coils, these being somewhat modified in order to produce the different kinds of currents that are demanded. The current generated by these machines does not pulsate, but, on the contrary, is continuous, which, besides giving a very steady light, is less dangerous than that of the pulsating type.

In the Weston arc lamps exhibited, the arc or distance between the carbons is short, being one thirty-second of an inch in length or thereabouts. There is a palpable advantage in this, for it permits a given number of lamps to be worked with a current the tension of which is correspondingly low.

The large incandescence lamps shown in such profusion in the Weston exhibit, were really the only lamps in the Exposition which showed a new and important departure in this type of illumination, although there were those of the smaller description which exhibited marked improvement when considered from an economical standpoint. The big lamp can be used in multiple arc or multiple series at points far removed from the generator.

In the Weston dynamo the current generated has an E.M.F. of 1,500 volts In the two great incandescence machines exhibited the E.M.F. was shown to be of 160 volts, the small lamp machines having an E.M.F. of 120 volts or thereabouts. The field magnet of the Weston machine resembles the letter C, having the poles in the center; the magnets are wound in shunt circuit, and are oblong in section.

The armature, which revolves between the poles, is composed of a core of iron disks strung like beads upon the shaft, being insulated the one from the other by disks of paper. The type of cylinder thus constructed may be said to be a modification of that employed in the Siemens machine. There are numerous coils, which serve to equalize the current generated, and brass bearings serve to insulate the shaft from the magnet.

In the automatic rheostat exhibited in connection with the arc lights, a magnet wound in shunt circuit attracts an armature connected with ratchet wheels. When, by reason of the turning off of lights, the current shows too great intensity, the armature acts, rotates the wheel, and this leads to more resistance being thrown into the field circuit. The field magnets, as a consequence, exert less magnetism; a smaller current results, and the power which has been driving the machine may be reduced. The resistance is released by an opposite process, and the full power of the shunt circuit may be thrown upon the magnet.

lab2.jpg (127593 bytes)

lab5.jpg (104649 bytes)

Weston Standard Cells


The incandescence system of lighting must be able, if it would be generally employed, to compete with gas in cost. Hence it may not prove uninteresting, having described the Weston incandescence light, to explain what it has accomplished when practically compared in cost with gas by persons having no interest in either the one or the other. A large manufacturing firm of Olneyville, R.I., recently tested two Weston dynamo machines, one of one hundred lights capacity and the other of fifty lights. The test was made during an entire year, from April 15, 1883, to April 15, 1884 - 3,397 hours, an average of 11 hours each working day; the object being to discover whether incandescence lighting or gas was the cheapest. The following figures were given by the firm as the result of their experience:

Number of lamps in the two circuits 170
Number of lamps broken in 3,400 hours 133
Average life of lamps 2,207 hours
The cost of operating for the entire year was as follows:
133 lamps broken, at $1.50 each $199.50
Cost of power 500.00
Cost of attendance 468.00
Cost of brushes, oil, and other supplies 52.00
Interest, 6 per cent, on $4,100 246.00
Total $1,465.50
They compare this with what they had previously paid for gas as hereunder:
Cost of gas, 170 seven-foot burners 3,397 hours,
4,042,430 feet of gas, at $2.00 per M
In Providence, where they say gas may be had for $1.75
per M., this cost would have been reduced to $7,074.26

This shows, as they say, that their Weston incandescence lamps cost them only one-fourth cent per lamp per hour, which is equivalent to gas at 37 cents per thousand feet.


Copyright © 2007 FTL Design
Last revised: 25 April 2007

Return to Weston main page