In 2013, three early electric lamps were acquired from a long-time collector in New Hampshire who started his collection in the late 1930s. While one lamp is clearly identified as a Schaefer lamp, the other two were a mystery, which sparked some curiosity. Could those lamps be made by Schaefer too? Throughout this text, I'll refer to them as Lamps "A", "B" and "C".
Lamp "A" is of the baseless variety, with just two platinum wire loops protruding from the bottom of the lamp. Such styles of electric lamps were common in Europe for many years but less so in the United States. Lamp "A" has two notable and rather interesting features, which triggered my curiosity. The first feature is the cross shaped glass bridge that separates the platinum leading-in wires. The second feature is the blue enamel-like bonding cement applied to the glass surrounding the looped terminals. This bonding cement was also used by other early manufacturers to discourage any movement of the lead-in wires where they form a seal around the glass which would compromise the seal, and cause premature lamp failure.
Lamp "B" is very similar to "A" with the addition of a base, specifically a Schaefer type lamp base, though not marked as such. Looking through the lamp's glass envelope from the top into the stem well, the same bright blue enamel is visible. A generous amount of white plaster is used as the bonding agent to secure the lamp base to the glass envelope. The blue enameling and general shape of the lamp's glass envelope and carbon filament aren't the only similarities between Lamp "A" and "B". Lamp "B" also features the same cross shaped glass bridge as Lamp "A". Starting to see the progression yet? Production Schaefer lamps are also known to have an ink stamp on the bottom of their plaster bases. This stamp provides the electrical specifications for the lamp including its operating voltage and candlepower. Lamp "B" contains these specs in typical Schaefer fashion, but it's hand-written in pencil as opposed to perfect characters generated by an ink stamper.
Lamp "C" is a marked Schaefer incandescent lamp, but still likely an early production version. In this form we see that the lamp's filament stem has evolved into a "trouser" shaped stem. The use of blue enamel is still heavily applied in Lamp "C". By late 1888, Schaefer lamps featured a more familiar "Y" shaped glass filament stem without the blue enameling. The progression from baseless Lamp "A" to early production based Lamp "C" is interesting to study. Just how early are Lamps "A" & "B"? Research tells us that the Schaefer Electric Manufacturing Company was organized in late 1885. The earliest illustration that I can locate, as of this writing, is dated April 10th, 1886 and shows two Schaefer lamps, each with the unique cross shaped glass bridge identical to Lamps "A" & "B". Knowing this, I would estimate "A" and "B" to be from 1885 and likely represent the very first forms of the Schaefer lamp produced between June 1885 (Frederick Schaefer's first patent release) and the formation of the company in late 1885.
At some point in the development of Schaefer's lamp, the plaster base changed to a pre-made wood base insert, likely to simplify manufacturing and reduce cost. The cross shaped glass bridge was dropped and a more familiar "Y" shaped glass filament stem was used. The contact pins on the bottom of the base also varied. Collectors have reported lamps with flat blade pins as opposed to the round pins, both equally spread apart.
In addition to these lamps, a genuine Schaefer lamp socket in remarkable condition was also acquired from the same collector which is pictured below for reference. The socket is stamped in a similar manner to Schaefer's production lamps.
"Y" shaped stem typical of most Schaefer lamps
Schaefer lamp socket
The Electrician and Electrical Engineer
A new incandescent lighting system was demonstrated in Cambridge on the 14th inst., the inventor being a young German named Frederick Schaefer. There has been organized under laws of Maine a stock company for the purpose of carrying the business of lighting by electricity. The inventions have been patented in this country, Canada, Mexico and Europe, and are entirely novel as compared with other systems. This exhibition was the first to which outsiders have been admitted. The most noteworthy feature of the new invention is that the carbonized filament in the incandescent lamp is composed primarily of a simple silk thread, which, when carbonized, remains as flexible as platinum wire. These filaments, the inventor claims, have been tested to last for over two thousand consecutive hours. Another peculiar feature is that one hundred thousand of these filaments can be prepared in ten hours, and the cost of their preparation is trifling. Each lamp has a brilliancy of from fifteen to thirty candles, and a two-horse power engine will drive a dynamo to a minimum capacity for furnishing thirty lamps. In this exhibition 250 lamps were maintained by a dynamo propelled by a 16 hp engine the light being white and of great brilliancy. The organization is known as the Schaefer Electric Manufacturing Co. and has a capital stock of $150,000 with power to increase the same. The officers are president L. Schlegelmilch; secretary and treasurer Werner Malsch; directors L. Schlegelmilch, Henry P. Veith, Ferdinand Schaefer, Peter Schell and Frederick Schaefer, the latter being the electrician of the concern. The inventor has a laboratory at Cambridgeport.
The Electrical World
April 10, 1886
The Schaefer Electric Lighting System- Among the incandescent light systems recently brought forward in the East is that of the Schaefer Electric Manufacturing Co. of Boston. Its electrician, Mr. Frederick Schaefer, has designed the dynamo, lamps and other necessaries which we illustrate in the accompanying engravings.
Fig. 1 represents the dynamo in which the Siemens armature is employed. The field consists of two pairs electro-magnets which are bolted to uprights on the base plate. There are two pairs of brushes on the commutator, which are adjustable independently of each other, so that either pair can be removed for readjustment when necessary, without stopping the current. While the dynamo is claimed to be self regulating, a regulator is provided which is placed on top of the machine, and is called into play when the speed of the machine varies on account of unsteadiness in the power.
The lamp employed in this system is shown in Figs. 2 and 3. It has a filament composed of carbonized silk. It fits into the socket shown in section in Fig. 5 and the switch is arranged to turn in either direction, for turning the current on or off. The lamp is firmly held in its socket, so that jarring does not loosen it nor affect the permanence of the contacts. The system also comprises safety fusible cut outs and circuit switches, one form of which is shown in Fig. 4. The circuit is closed through a double arm making contact between two springs. For heavy currents the double pole switch is employed, which breaks contact simultaneously on both sides of the circuit.
It is stated that several factories in Haverhill, Mass., and the railway depot at Concord, NH are lighted by this system.
The Electrical World
February 24, 1886
The Schaefer Electric Light Co. of Cambridgeport, Mass. is making an installation of its system in the Continental Brewery, at Roxbury. The Armington & Sims engines will be used.
The factory and offices of the Schaefer Electric Manufacturing Co. are located on the corner of Osborne and Main streets, Cambridgeport, Mass. The company been in existence only a few months, yet the push and go aheadativeness of its promoters, backed by a reliable and an excellent lamp, has the prominently before the public. The company fitted up several plants in New England and in every case a satisfactory report has been given. The facilities for manufacturing both dynamos and lamps are such as to enable this company to fill orders promptly. The company manufactures lamps from 10 to 100 cp and with its system all sizes can be used, it is said, on the same circuit. The carbon differs from that used in any other incandescent lamp, it being an animal carbon (silk specially prepared) for the filament, the process having been patented by Mr. Frederick Schaefer, the electrician of the company. The fibre of this material is continuous throughout its length and uniform in its section; it is so flexible that it can be straightened out without breaking, and will stand a very high incandescence, producing an extremely white and pleasing light. The dynamo lamp and other apparatus made by the Schaefer Company were illustrated in THE ELECTRICAL WORLD April 10th.
Leading Manufacturers and Merchants of Eastern Massachusetts
Schaefer Electric Manufacturing Company, Factory, corner Main and Osborn Sts., Cambridgeport. The Schaefer Electric Manufacturing Company have introduced and also originated many of the new ideas now in use in the production of the electric light. This company was incorporated in 1885 with a capital of $150,000, and from that time onward has fitted up many electric plants in all parts of this country and Canada. There are several considerations of great importance in connection with the electric light as produced by this company. In the first place, its great economy and safety; secondly, its superiority over any other mode of illumination, and, finally, there can be no doubt but that the electric in regard to healthfulness is far in advance of any other artificial light - in fact, these considerations have been practically demonstrated, and hence the Schaefer Electric Manufacturing Company are doing a large business manufacturing dynamo machines and incandescent lamps from ten to one hundred candle power, and supplying electrical instruments and complete installations of incandescent plants. The premises occupied are 40x150 feet in size and well adapted to the business, and supplied with steam power to facilitate the operations of the workmen. Special attention is given to making repairs, and it can be truly said that the works are complete and perfect in all their appointments and equal in every respect to the best in the country. The president of the company is Mr. Leopold Schlegelmilch and the treasurer is Mr. Weiner Malch, both of whom are practical, skilled business men. They are natives of Germany. The company is represented in Philadelphia by an agency on Arch street, near Broad, and also in all the cities in the country.
The Electrical World
January 15 , 1887
The Schaefer Electric Manufacturing Company reports business as now being much better than at any other period since organization. Its lamps are being more and more appreciated as their meritorious features become known. Many electric companies who have used the Schaefer lamps are now sending larger orders. Among the recent shipments of lamps made this company were the following: Daft Motor Company, New York; Enterprise Electric Manufacturing Company, New York; Wachusett Electric Light Company, Fitchburg, Mass.; Taunton Mass. Electric Light and Power Company; and Texas Electric Light and Power Company, of Dallas, Texas. In addition to several large orders filled for primary battery companies, large lots of lamps have been shipped to California and other far Western points. In a recent interview with the president of the company Mr. L. Schlegelmilch, that gentleman made the following statements about the Schaefer lamps: "Our 50 volt standard lamps can be varied from 45 volts to 50 volts and are kept so in stock. They can be made to order for from 50 to 150 candle power. Our 100 volt standard lamps also can be varied and kept so in stock from 90 volts to 104 volts. To order they can be made from 50 to 150 candle power. We also make 16 and 20 candle power lamps for 35, 65, 70, and 75 volts. We have just made some 4, 5, 8, and 10 ampere lamps for arc light circuits, giving from 20 to 200 candle power."
The Electrical World
March 19 , 1887
The Schaefer Electric Light Company of Cambridgeport, Mass. reports being behind orders on its incandescent lamps.
The Electrical World
June 4 , 1887
Mr. Leopold Schlegelmilch of the Schaefer Electric Manufacturing Company has just fitted up his restaurant on Water Street, Boston, with a complete incandescent lighting outfit which adds to the attractiveness to say nothing of the improvement in illumination of the place. It is almost unnecessary to state that the Schaefer system is used.
The Electrical World
July 16, 1887
For some time past the Fort Wayne Jenney Electric Light Company has been elaborating a system of incandescent electric lighting under the supervision of its electrician, Mr. Schaefer, and the result has been the construction of dynamo and lamps of novel design.
The Electrical World
February 25, 1888
Not Manufacturing Dynamos-The Schaefer Electric Manufacturing Company of Boston has discontinued the manufacture of dynamos for incandescent electric lighting as once before announced in my notes. This company has however increased its manufacturing facilities in its lamp and incandescent outfit departments and large orders for the Schaefer lamps are being promptly filled daily at the company's Cambridgeport Mass. factory. President Schlegelmilch reports a large demand for the Schaefer lamp from various sections in the west and south as well as along the Atlantic seaboard.
March 31 , 1888
Hawkeye Electric Company- The Hawkeye Electric Manufacturing company of Oskaloosa, Iowa, is a young, but growing, and energetic corporation. The company was organized but a little over two years ago. Finding its quarters too small for its constantly increasing business, the company was forced to erect suitable buildings of its own. The buildings were completed, and the company moved into them November 10, 1887.
This company manufactures arc lighting machinery; incandescent lighting machinery; electric motors for both arc and in candescent circuits, or for any kind of current; voltmeters; ammeters and electrical instruments. The officers are W.F. Durfee, president ;C.P. Searle, secretary and treasurer; and E.H. Gibbs, vice president. They are all well known business men and capitalists of the city. William Bowen, the general manager, is a well known and popular business man, and has charge of the city water works, in addition to his responsible position with this company. Frank Thone, the electrician of the company, is well known among electrical men and is a gentleman of high scientific attainments. The company have recently secured the services of Mr. Schaefer, formerly of Fort Wayne, who will assist Mr. Thone and have charge of the incandescent lamp department. The company will erect soon a large addition to the works.
The Electrical World
September 1, 1888
The Schaefer Incandescent Lamp- We illustrate on this page the new lamps of the Schaefer Electric Manufacturing Company, of Boston. Fig.1 is a cut of a 100 c.p., 100 volt lamp, about one-half size. This lamp is well adapted for large halls and places where much light is required, and besides furnishing the same amount of light as a number of smaller lamps, will give as good distribution and prove less expensive on account of saving in wiring and number of fixtures. These lamps are made to different voltages and have an efficiency of 2.7 watts per candle.
The holder or socket is constructed with the utmost simplicity, and the contact between lamp and holder is thoroughly reliable. The electrical connections are completed on inserting the lamps, which are perfectly insulated throughout, this insuring to the person handling them no possibility of coming in contact with the current.
The increasing demand for low resistance lamps, to be used in series, on account of the advantages where distribution over large territory is desired, as well as their ready adaptation to use on arc light circuits, has induced this company to manufacture lamps with suitable devices for this purpose. Fig.2 shows a combined fixture, complete, with a 100 c.p. lamp. The company also make lamps of 25 and 50 c.p. capacity, adapted to run on dynamos of all the ordinary amperages of current. These lamps have an efficiency of 2.5 to 2.8 watts per candle.
In the use of these lamps it is necessary to provide, in case of failure of a lamp, the the circuit should no be broken and that there shall be no possibility of coming in contact in handling, with the high tension current used. Both of these features have been provided for. The socket and holder which carry the lamp are so constructed that if a lamp is removed by accident, or otherwise, it closes the circuit automatically, and thus does not disturb the circuit or invite damage from the current.
The contacts and conducting parts are made heavy to allow free passage of the strong currents sometimes used. The holder also contains a paper cut-out, which in case of breakage of lamp, closes the circuit, and which can be easily replaced by removing the shell.
The ceiling block, as seen in the cut, Fig.3, also contains a paper cut-out under the brass rosette, and a switch for closing the circuit in case the lamp is not in use. The binding posts are concealed in wooden blocks diametrically opposite each other, thus again avoiding any possibility of coming in contact with them, the wires being held by a screw countersunk from the face of the block, so that it can be easily wired.
Electrical Trades Directory
Handbook for 1889
Schaefer Electric Manufacturing Company, Manufacturers of the Schaefer Dynamo and Lamps, Boston and Cambridgeport, Mass.
Schaefer, Frederick, Inventor of the Schaefer System (Schaefer Electric Manufacturing Company, Boston, Mass.) and Superintendent of the Fort Wayne Jenney Electric Light Company, Fort Wayne, Ind.
Volume III, 1892
Otis K Stuart, City Trust Building, Philadelphia, the well known electrical engineer and late treasurer of the Germania Electric Co., of Boston, has now established himself in Philadelphia, Pa. as agent for that company in the southeastern district, which comprises all of the territory usually known as the southern states, together with Pennsylvania and New Jersey. From the fact that the Germania Co. bought out the old Schaefer Electric Manufacturing Co. it is thought by a large number of people that the Germania Co. is merely maker of the improved Schaefer incandescent lamp; but this company is now manufacturing every appliance used in incandescent lighting, from dynamo to lamp.
February 15, 1902
THE BRYAN-MARSH COMPANY, of 136 Liberty street, New York, points with pride, very properly, to its historic record of twenty years. The company was established under the name of the Schaefer Electric Company, at Cambridge, Mass., as makers of incandescent lamps. The plant was removed to Marlboro in 1891 and incorporated as the Germania Electric Company with added capital. In 1894 the entire business was purchased outright by the Bryan-Marsh Company, the most modern machinery installed and the entire interest devoted to the manufacture of incandescent lamps. At the present time the factory has a total capacity of over 20,000 lamps per day, and under the energetic management of Mr. Converse D. Marsh, the head of the company, has won an enviable reputation for excellence and reliability of product.