IMPROVEMENTS IN GLOBES FOR INCANDESCENT ELECTRIC LAMPS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I JAMES GRIEVE LORRAIN of the Whitehall Club, Parliament Street, in the City
of Westminster Consulting Engineer do hereby declare the nature of my Invention
for IMPROVEMENTS IN GLOBES FOR INCANDESCENT ELECTRIC LAMPS to be as
follows:-
My invention relates to improvements in Globes for incandescent electric lamps
whereby greater light for a given absorption of electric current is obtained, and a
more plea-ing effect produced, objects already attained, though in a different way,
by the means described in my patent No. 5738, dated 31 December 1881.
In carrying out my said invention I employ a bulb or globe part of which is
composed of clear or transparent glass and part of a kind of glass which inay
conveniently be described as "metallic-glass." This "metallic-glass" consists of
clear or translucent glass with opaque metallic or other particles mechanically
suspended therein, preferably small particles of metallic foil, mica or other more or
less reflecting materials. The bulb may conveniently be blown on what I may call
a compound tube one half or other desired portion of which extending from end to
end of the tube is of clear glass, and the remaining half, or other proportion,
extending from end to end, of "metallic-glass." Or the bulb may be blown from
two tubes, one of clear glass and one of "metallic glass," stuck end to end in a well
known manner.
The compound tube may be made by squirting over a mindrel,
or otherwise, the two kinds of glass issuing from separate receptacles, and inceting
just before reaching the orifice from which they are squirted.

page_text: COMPLETE SPECIFICATION.
I, JAMES GRIEVE LORRAIN, of the Whitehall Club, Parliament Street, in the City
of Westminster Consulting Engineer do hereby declare the nature of my invention
for IMPROVEMENTS IN GLOBES FOR INCANDESCENT ELECTRIC LAMPS and in what
manner the same is to be performed, to le particularly described and ascertained
in and by the following staternent :-
My invention relates to improvements in globes for incandescent electric lamps
whereby greater light for a given absorption of electric current is obtained and a
more pleasing effect produced; objects already attained, though in a different way,
by the means described in my patent No. 5738 dated 31 December 1881.
In carrying out my said invention I employ a bulb or globe part of which is
composed of clear or transparent glass and part of a kind of glass which may
conveniently be described as metallic or granitic glass. This metallic or granitic
glass may consist of clear or translucent glass with opaque metallic particles
mechanically suspended therein, such as particles of metallic foil or metallic filings;
or it may consist of clear or translucent glass with non-metallic particles of a more
or less reflecting nature mechanically suspended therein, such as mica, talc &c.
The bulb or globe may conveniently be blown, or otherwise formod, ou what
I may call a compound tule one half or other desired proportion of which, extending
from end to end of the tube, is of clear glass, and the remaining half, or other
proportion, extending from end to end, of metallic or granitic glass.
Or the bulb may be blown from two tubes, one of clear glass and the other of
metallic or granitic glass, stuck end to end, as will be readily understood.
The compound tube may be made by squirting over a mandril, or otherwise, the
two kinds of glass issuing from separate receptacles and meeting just before reaching
the orifice froin which they are squirted.
The object of this invention is to obtain the appearance of a solid mass of light
an object which it has been sought to obtain by frosted or semi-opaque or opal
globes or bulbs, all of which plans however only attain the end desired by a great
sacrifice and loss of light-a loss averaging upwards of forty per cent-a very
serious matter in an illuminating agent which has to compete with such powerful
rivals as gas and oil. In experimenting upon lamps made under my Patent
No. 5738 of 1881 I found that if instead of having a single extended reflecting
surface employed a surface made up of a very large number of extremely minuto
and separate reflecting surfaces reflecting at slightly different angles, 1 obtained
exactly the effect that I wanted, avoided all loss of light, and was able to gain
increased and advantageous effect by concentrating the light in any desired
direction or directions. In this specification I have described the method of
carrying this into effect.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the saine is to be performed, 1 declare that what
I claim is
In incandescent electric lamps, a globe or bulb consisting partly of clear or
translucent glass and partly of inetallic or granitic glass substantially as herein set
forth.