The lamp shown here is a pressed or multiple tungsten lamp. These tungsten filament lamps were first developed independently by a number of inventors (most notable those from Germany and Austria-Hungary before the First World War). The filaments were produced by mixing powdered tungsten with a sugar and gum solution, squirting the resulting paste through a diamond die, and then baking the resulting strands so that they became pure tungsten filaments. But since tungsten is normally a very brittle metal, the filaments could only be produced in short, fragile segments that broke easily, despite the best intentions of many a scientist to create a strong, unbreakable tungsten filament. Hence the use of several shorter strands of filaments rather than a single long filament of tungsten inside a lamp. These short filaments were then connected in series in order to give off a great deal of light. This new lamp was thus called a “Multiple Tungsten Lamp” or even a “Tungsten Multiple Lamp.” General Electric in 1906 paid the inventors of this non-ductile tungsten lamp a sum total of $1.5 million dollars in order to secure the patent rights to this new filament. The next year, in 1907, these lamps were introduced in this country. With their long life (about 800 hours) and the increased brightness over the pure carbon lamps, they proved to be very popular with the public. However, they were not without their faults. Their delicate filaments could not withstand rough handling and the lamps could only be mounted in an upright position. Thus General Electric scientists were still searching for even a better filament for the electric lamp – one that was once deemed unattainable – a tough ductile tungsten filament that could be manufactured in longer segments and still remain unbroken.* The manufacturing of these non-ductile tungsten lamps was discontinued in 1919 (the same year tip-less bulbs came out).
* Later research by a General Electric scientist led to the development of drawn tungstile wire (see Figure 72 ).
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