4. First case study – the subdivision of the light - HM Treasury

F05 Ch4 Subdivision of the light.doc
05/04/2006 19:34:00
Technological roulette – a multi-disciplinary study of the dynamics of innovation in electrical, electronic
and communications engineering.
4. First case study – the subdivision of the light
with various materials – first with incandescent
platinum wire, and then with carbonized
filaments, derived from bamboo, enclosed in an
exhausted bulb – he, Swan, had used cotton
threads, which he treated by immersion in
sulphuric acid, so as to turn it partly into
cellulose, before carbonization. These threads
or filaments were then enclosed in glass bulbs
from which the air was thoroughly exhausted by
a Sprengel pump. This part of the invention,
he told me, had been worked out for him by
Stearn, a Liverpool banker, who had for years
specialized in designing and improving the
Sprengel vacuum pumps.
Up to this time I had not supposed that
the new idea of incandescent lighting was
likely to pass from the experimental to the
practical stage, and, in the pamphlet which I
had written and published a short time before
my visit to Newcastle on Electric Light for
Industrial Uses, had confined myself to
pointing out the various purposes to which
lighting by small arc could be profitably
applied. For Edison’s experiments, of which I
had heard, with incandescent platinum wire,
and later with thin horseshoes of carbonized
paper, enclosed in vacuum bulbs, were still at
that time only in the laboratory stage. But
now I saw at once that Swan’s invention
would open a new chapter in the history of
electric lighting.”
99
Crompton 1928, p93
Crompton was subsequently appointed Chief Engineer of the first Swan Electric
Lamp Company was formed in Newcastle, and he played an important part in the
negotiations which shortly afterwards led to the formation of a larger company in London.
Over the next few years, in addition to the problems of establishing the manufacture
of electric lamps, a project which occupied Swan’s attention was the use of the
incandescent light bulb as a miner’s safety lamp. His first example consisted of a strong
glass bell, protected by a cage of wires enclosing a small incandescent lamp. The lamp
was connected by a flexible conductor directly with the main source of supply at the top of
the mine shaft, or with an intermediate storage battery carried on a trolley near where the
miner was working. This lamp, however, was not a practical substitute for lamps
generally used in the pits at that time.
Crompton1928
Fig. 4.33 Alternative views of the
Crompton portable generating machine