India Rubber and Gutta Percha and Electrical Trades Journal. Vol. 4, no. 2 (Sept. 8, 1887)

              THE INDIA-RUBBER AND 
AND 
ELECTRICAL TRADES JOURNAL.
VOL. IV., No. 2. SEPTEMBER 8, 1887. PRICE
ONE SHILLING & SIXPENCE.
OODSTTEIITTS.
India-Rubber, Gulta-Percha and
'other^Insulating Materials ..
Hamburg Rubber Exports ..
Hot Boxes .. .. .. ..
NOTES BY " QUIZ"
Forster & Gregory, Limited
Elastic "Web Trade of Leicester ..
Origin and Progress of the India-
Rubber Manufacture in England
United States Rubber Statistics ..
LEADING ARTICLE. — Euphorbia
Gum .. .. .. • •
NEW INVENTIONS, NOVELTIES, &C.
A Waterproof Bonnet .. ..
New Life-Saving Invention
HOMES OF INDUSTRY. — Luke
Turner & Co ..
India-Rubber in Assam .. ..
Merchandi.se Marks Act .. ..
Tuck's Packing Factory .. ..
NEW BOOKS, &C ..
ELECTRICAL NOTES .. ..
Caoutchouc-Yielding Plants ..
The Shamrock File
PAGE
25
28
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29
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31
33
35
37
38
39
39
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41
42
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44
46
New Companies .. ,
New Patent Law, &c. .
BANKRUPTCIES, &c... ,
Executions by Electricity .
ADVERTISEMENTS.
Abbott, Anderson & Abbott
Adkin, Thos., & Sons ..
Armitage, Sir E., & Sons ..
Arnott & Button .. ..
Bailey, Wm., & Son ..
Barnes, W. C., & Co. ..
Barrow, Franklin .. ..
Bartrum, Harvey & Co. ..
Beldam Packing Company
Birnbaum. B. .. ..
Black, J. W
Brown, W. L. C. .. ..
Canfield Rubber Company
Carless, Capel & Leonard..
*' Ceramyl" .. .. ..
Clark, Sons & Co. ,. ..
PAGE 46. Clayion Aniline Company PAGE xi.
.. 47 Clouth, Franz .. ..
.. 47 Cohen, B. .. .. ..
. 48 Dukep, Bernhard .. ..
Elrick & McPherson .. .. XVIU.
Eschmann, Bros., & Walsh .. xiv.
Fleming, David .. ..
.. XX. Forster & Gregory .. ,,
. vx. Frankenburg, Isidor ., .. ii., 48
.. XI. Frankenstein, P., & Sons .. . . XVIU.
Frendenburg, F., & Co. .. .. XV.
. xvin. Garnock, Bibby & Co. .. 111.
.. xvii. Galloway, W. & J., & Sons .. 111.
Glasgow. & Laing .. .. .. — Hancock, Jas. Lyne .. 32
.. vm. Hutchinson, A., & Co. .. .. XVII.
Jesseman, W., & Co. .. .. VUL.
. . XVI. Kindersley & Johnson .. . . XIX.
. . IV. Laird & Alexander.. ..
0. XIV. Ledger, Wm... .. .. . . XIV.
.. V. Liverpool Rubber Company .. vm.
. . XVIU. Loewenthal & Morganstern .. xvi.
.. 48 Manders, Albert S., & Co...
Mandleberg, J., & Co. ..
.. 48
.. vm.
Markus Harris .. .. PAGE vi.
Meldrum, D. M., & Co. .. ••
Mills, John iv.
Moselcy, David, & Sons •. .. 36
Nichols, John .. .. .. xiv.
North British Rubber Company .. x.
Patent Door Buffer Company .. xvii.
Pirelli & Co .. .. v.
Reddaway, F., & Co. . . • xix.
Robinson. Jos., & Co. .. .. xv.
Rossendale Belting Company .. xvi.
Rowley, Thos., & Co. .. .. vi.
Rothwell, John .. .. ix.
Shaw, Francis .. .. xii.
Smith, Alfred xii.
Smith, John .. .. .. .. xii.
Thompson, Samuel.. .. ». xiv.
Tomey & Sons .. .. .. xii.
Tuck & Co. .. .. .. XX.
Typke & King .. .. .. x.
Victoria Rubber Company .. x.
Warne, Wm., & Co. .. .. i.
Wertheim, Louis .. .. v.
Worth, T., & Co. .. .. iii.
[Where the numerals are omitted the advertisment does not appear in this issue.]
INDIA-RUBBER, GUTTA-PERCHA, AND OTHER
INSULATING MATERIALS COMPARED.
| H E v a s t d e v e l o p m e n t o f t e l e g r a p h s ,
telephones, and electric lighting has
necessarily brought to the front the im­portant
question of efficient insulation.
Our able contemporary, the Telegraphic
Journal and Electrical Review is of
opinion that the subject has been
somewhat neglected, and that poor
insulation has been the cause of some notorious failures
in electric lighting. Accordingly in three recent numbers
of the journal just mentioned, the matter is very
exhaustively treated, and the merits and demerits of all
the materials ordinarily used as insulators are fully set
forth. The entire article (or rather series of articles) is
well worth perusal by all connected with the manufacture
of telegraph lines or lighting leads, but we shall here
briefly summarise the conclusions arrived at with reference
to the various insulating substances treated of. ,
After alluding to the fact that almost every conceivable
substance, vegetable and mineral, has been made use of
by inventors in the hunt after something cheap and at
the same time efficient, our contemporary remarks :—
The yearly increasing cost of India-rubber and gutta-percha has had
the effect of giving a great stimulus to the manufacture of compositions,
endless in number, and infinite as to the variety of materials employed.
It is not too severe a verdict to condemn the majority of these com­pounds
as valueless. Many of them certainly give a very high
insulation directly after manufacture, and when first laid down.
These tests are, however, pre-eminently fallacious, for the leads
have not undergone the vicissitudes which surely await them
in their subterranean or overhead life. They have as yet experienced
no sudden or severe changes from heat to cold, from wet to
dry ; they have been subject to no rough handling, to no bending
or twisting, to no removal and replacing, to no blows or heavy pressures.
These are frequently the conditions, in no way exaggerated, to which
electric light leads are exposed, and under which the mechanical
qualities of the compositions above referred to are found to be totally
inefficient.
Good insulation and mechanical perfectness are not, however, the
only points to be considered in the selection of a material. Although
electrostatic capacity with regard to its retarding influence upon
currents has been frequently referred to in connection with underground
electric lighting leads, its effect is generally admitted to be inappre­ciable,
for the reason that the lengths of circuits dealt with in electric
light installations are comparatively short. This reason is so sufficient
that even in the employment of alternating machines where rapid and
successive changes of current take place, the question might almost be
summarily dismissed from consideration where ordinary lengths of
conductor are deaft with.
The quality which the insulating substance possesses of allowing
some portion of the heat generated in the wire to be conducted to the
surface, and there dissipated into the surrounding air, without
prejudicing the insulation, is a most important matter, but unfortunately
experiments have as yet been insufficient in providing the data
necessary to enable us to speak with any decided opinion on the
subject, or if such experiments have been carried out to any practical
extent, the results, with one or two exceptions, have not, so far as we
can call to mind, been made public. We shall, consequently, limit our
remarks to the consideration of insulation and mechanical qualities,
and we would here point out that while insisting on the necessity of
good insulation, the mechanical attributes of the materials to be
employed are of much greater importance.
In America, where electric lighting is far more extensively made use
of than in this country, there seems to be a correspondingly greater