Tim Tromp recently put a message on his website that discussed a Seel lamp which had been acquired for his collection. The writer of this article recommends that anyone interested in the Seel lamp click onto the links in References 2 and 3 below. Clicking onto the Reference 4 link will take you to Seel patent No 382,560.

The following is a verbatim article that appeared in 1888 on a Seel lamp¹.

"The Seel Incandescent Lamp "A new incandescent lamp, recently invented by Herr Seel, is being introduced in the Berlin installations. It is made either with a single or double filament, and of a power of from 8, 10, to 30 candles, but recently larger lamps, giving a light of from 200 to 300 standard candles, have been made. The voltage varies from 35 to 100 volts. The inventor claims that in small lamps the energy required per candle is about 3 watts, but in the 200 candle size only 2 watts. The pear-shaped globe, has no point in the centre, so that the light is freely emitted in all directions. The lamp is provided with a metal socket, into which it is cemented by plaster of paris, but the end face of the socket is protected by a disk of serpentine, through which the lamp wires pass. In this way the plaster of paris is prevented from absorbing moisture. The socket is fastened by a bayonet joint into a somewhat larger socket which is free to revolve on a plate, on the face on which are spring terminals of the branch wires, which are brought through the tube of the bracket. Two little studs, which are screwed into the serpentine plate, and are connected with the lamp terminals, form the contact with these springs when the holder is turned into a certain position. When the holder is turned 90° on its vertical axis this contact is interrupted, so that the light is switched on and off by turning the whole lamp with its holder on its axis. In order to avoid touching the lamp itself when switching on or off, the outer socket is provided with a slot, into which engages a pin on an arm, the prolongation of which is shaped into a handle of about the size used with an ordinary gas tap. By turning this handle the rotary movement in one or the other direction is imparted to the outer socket, and to make sure that even in careless hands the quarter turn should be fully completed, so that the contacts shall be either completely made or completely broken, the spindle of the tap is provided with a disk having flats, against which presses a spring.The filament is prepared from a vegetable or animal fibre, the exact nature of which the inventor keeps secret. In cross section the filament is triangular, and consists of three layers."

If one looks at this website under the heading "Lamp Collections and Exhibits", then under the topic dealing with the William J. Hammer Collection, some photographs can be viewed. If one clicks on "Lamps Developed by Other Workers by 1904", a Seel lamp can be seen on the top row of lamps, third from the left end. If one examines, under magnification, the card for that lamp on the original photograph it can be seen that his Seel lamp was manufactured in the year 1900.

The writer viewed the Hammer Collection many years ago when the lamps were on display at the Ford Museum. Notes were jotted down regarding several lamps in the display. The writer wrote, about one particular lamp: "A Seel lamp, made in 1890, had a base like Mather but evidently with a pin in the base center⁵."

References
1) "The Seel Incandescent Lamp", Western Electrician, Vol 2, No 9, Mar 3, 1888, pg 112.
2) Tim Tromp's Discussion Forum, pictures of his Seel lamp
3) Tim Tromp's pictures of his Seel lamp
4) United States Patent and Trademark Office, Patent No. 382,560, issued to Carl Seel. If a message saying "Search Time Has Expired", then click on "Full Text" and in the next window click on "Images."
5) This website, in Section 12, see "Comments on Some Hammer Lamps at the Ford Museum."