3990 
NATURE 
Slag 9 a nds 
(Feb. 22, 1883. 
sum of money will be distributed in prizes for inventions 
and improvements of fishing gear; the special prizes in this 
department alone will number over 100, ranging in value 
from 600/. to 27. ros. Over 1000/. will also be given for 
essays on various topics connected with the economy of 
the fisheries and the natural history of our more im- 
portant food fishes, as also for papers on fishery legisla- 
tion. The dissemination of the knowledge to be obtained 
from such essays as may be awarded prizes is important. 
None of the essays contributed to the Norwich Exhibi- 
tion have been published, except that of Sir James Mait- 
land, printed presumably at his own expense, so that 
whatever information was contained in the Norwich prize 
essays remains only in the cognisance of those who read 
them. The Edinburgh prize essays are, we believe, being 
printed. Surely they might have been published ere this, 
and it might be taken into consideration by the executive 
of the present Exhibition, whether it is possible to have 
the essays judged, the prizes awarded, and a print of 
such as are worthy of being published on sale in the 
building in the course of the summer: a popular “ hand- 
book” to the Exposition will, we may presume, be issued. 
As to “exhibits” of a useful kind, suchas those of fishing 
gear of every description, men with a practical turn of 
mind will be able to take stock of them and perceive at 
a glance how far they can be utilised. As a class, fisher- 
men are slow to learn and chary in the way of trying 
experiments, but it is not impossible that the approaching 
Exhibition may contain the germs of some new ideas 
which may prove alike practical and profitable. 
THE PROGRESS OF TELEGRAPHY 
“ps8 first of the series of six lectures on the Applica- 
tions of Electricity was delivered on Thursday 
evening, February 15, at the Institution of Civil Engi- 
neers, on “ The Progress of Telegraphy,’ by Mr. W. H. 
Preece, F.R.S., M.Inst.C.E., of which the following is an 
abstract :— 
Telegraphy is the oldest practical application of elec- 
tricity. It grew about the railway system, and was ren- 
dered a practical agent by the foresight of Robert 
Stephenson, I. K. Brunel, Joseph Locke, and G. P. 
Bidder, who were its godfathers in England. Electric 
currents are, as a rule, maintained for telegraphic pur- 
poses by the combustion of zinc, and in the innumerable 
forms of batteries in use, the conversion of zinc into 
sulphate of zinc is the root of the transformation of 
energy into that form which was utilised as electric 
currents. There are three forms of battery in use in the 
British Post-Office Telegraph system, and in the following 
numbers :— 
Daniell ew n 87,221 cells. 
Leclanché srk went 56,420 ,, 
Bichromate 21,846 ,, 
Every administration has its own adopted form, dif- 
fering in design, but based on one or other of these types. 
Magneto-electricity is employed for some forms of appa- 
ratus, and dynamo-machines are sometimes used to 
supplement batteries. Experiments are now being made 
with secondary batteries. The various terms employed— 
electromotive force, resistance, induction, and current— 
though measurable in definite units, have not yet become 
household words ; but, being admitted into commercial, 
legal, and Parliamentary lore, they will soon be as 
familiar as feet, gallons, or pounds. 
Electric currents are conveyed from place to place 
either overground, underground, or submarine. 
Overground.— Wooden poles preserved in creosote are 
employed in England, but iron poles are extensively used 
in the colonies. The conducting wire is almost uni- 
versally of iron, but copper wire is much used through 
smoky places where iron is liable to rapid decay. 
Phosphor-bronze wire is under trial, and is a very 
promising material, as it possesses the conductivity of 
copper with the strength of iron. The improvements 
made in the quality of iron wire have been very great, 
and it conducts now fully 50 per cent. better than it did 
a few years ago. Electric tests have had a marvellous 
effect upon the production of pure metallic conductors ; 
copper has improved in even greater ratio than iron; 
samples have been produced better even than the standard 
of purity. The insulators remain principally of porcelain, 
and their forms vary nearly with the number of indi- 
viduals who use them; the only improvement of any _ 
value recently made is one which facilitates the very © 
necessary process of cleaning. 
Underground.—Wires are almost invariably carried 
underground through towns. Copper wire, insulated — 
with gutta-percha, incased in iron pipes, is the material 
used. There are 12,000 miles of underground wire in 
the United Kingdom. There is a great outcry for more 
underground work in England, owing to the destruction 
to open lines by gales and snowstorms ; but underground 
telegraphs, wire for wire, cost at present about four times 
as much as overground lines, and their capacity for the 
conveyance of messages is only one-fourth ; so that over- 
ground are, commercially, sixteen times better than 
underground wires. To lay the whole of the Post-Office 
system underground would mean an expenditure of about 
20,000,0007. Hence there is no desire to put wires under- 
ground except in towns. Besides snowstorms are few 
and far between, and their effects are much exaggerated. 
Of the numerous materials and compounds that have 
been used for insulating purposes, gutta-percha remains 
the oldest and the best for underground purposes. It, 
like all other materials used for telegraphy, has been 
improved. vastly through the searching power that the 
current gives the engineer. 
Submarine.—The past ten years has seen the globe 
covered with a network of cables. Submarine telegraphs 
have become a solid property. They are laid with facility 
and recovered with certainty, even in the deepest oceans. | 
Thanks to such expeditions as that of H.M.S. Challenger, 
the floor of the ocean is becoming more familiar than 
the surface of many continents. There are at present 
80,000 miles of cable at work, and 30,000,000/. have been 
embarked in their establishment. A fleet of twenty-nine 
ships is employed in laying, watching, and repairing the 
cables. The Atlantic is spanned by nine cables in work- 
ing order. The type of cable used has been but very 
little varied from that first made and laid between Dover~ 
and Calais; but the character of the materials, the 
quality of the copper and the gutta-percha, the breaking 
strain of the homogeneous iron wire, which has reached 
go tons to the square inch, and the machinery for laying, 
have received such great advances, that the last cable 
laid across the Atlantic, by the Telegraph Construction 
and Maintenance Company, was done in twelve days 
without a hitch or stoppage. 
Ideas are conveyed to the mind by electric signals, 
and in telegraphy these signals are produced at distant 
places by using two simple electrical effects: (1) that a — 
magnetic needle tends to place itself at right angles to a 
wire when an electric current passes through it; and (2) 
that a piece of iron becomes a magnet when a current of 
electricity circulates around it. An innumerable quantity 
of tunes can be played on these two strings. Various 
companies were established at different times to work 
certain systems, but when the telegraphs were absorbed 
by the State the fittest were selected to survive, and their 
number consequently declined. 
The ABC instrument is the simplest to read, for it 
indicates the jetters of the alphabet by causing a pointer 
to dwell opposite the desired letter. There are 4398 in 
use. Its mechanism is, however, complicated and ex- 
pensive, and it is being rapidly supplanted by the tele- 
phone. The needle instrument is the simplest in con- 
