93 



TELEGRAPH, ELECTRIC. 



TELESCOPE. 



can be transmitted with equal rapidity in whatever language or cipher 

 they may be, and the perforated bands may be prepared at leisure, and 

 even be subjected to the revision of a corrector. 



Although this system is being extensively introduced in the metro- 

 polis and elsewhere, it does not interfere with the working of other 

 companies, such as the Electric and International Telegraph Company, 

 as it is now called, which transmits messages not only to all parts of 

 the United Kingdom and Ireland and the Continent, but also by street 

 lines between various parts of the metropolis, its central station in 

 Lothbury gathering up the messages from its branch offices, and trans- 

 mitting them to distant stations. Arrangements are made for sending 

 messages at small cost between any of the metropolitan stations, of 

 which at the time we are writing there are about S3. In addition 

 to these stations there are wires between the Octagon Hall in the 

 Houses of Parliament, and the St. James's Street Commercial Station, so 

 that during the sitting of Parliament an abstract of the business of the 

 two houses is made every half hour as it proceeds, and is posted up at 

 the various club-houses, and also at the Italian Opera House. Members 

 can thus know whether their presence is required in the House or not. 

 The Opera House wire communicates with the Strand office, so that 

 messages may be sent thence to all parts of the kingdom. The 

 government wires proceed from Somerset House to the Admiralty, and 

 thence to Portsmouth and Plymouth by the South-Western and Great 

 Western railways. 



The Portsmouth and Plymouth Dockyards also communicate by 

 means of subtevanean lines with the naval establishments at Deptford, 

 Woolwich, Chatham, Sheerness, and with the Cinque Ports of Deal 

 and Dover. These wires are worked independently of the Telegraph 

 Company, and the messages are sent in cipher, the meaning of which is 

 not known to the clerks who transmit the signals. There are also 

 wires running from Buckingham Palace, and the chief Police Office in 

 ud Yard, to the station at Charing Cross, and thence on to 

 Lothbury, whilst the Post-Office, Lloyd's, the Stock Exchange, and 

 the Corn Exchange, communicate directly with the Central Office. 



At the present time almost every important town in Great Britain 

 is furnished with means of telegraphic communication to other 

 towns. As fast as any new railways, whether trunk or branch lines, 

 are opened, so surely is the telegraph laid down ; insomuch that 

 igth of telegraph is nearly coincident with the length of rail. 

 The exceptions to this rule are so few as scarcely to disturb the 

 simplicity of the rule itself. From numerous places in the metropolis, 

 messages are every day being quickly flashed to Aberdeen in one 

 direction, to Liverpool in another, to Dover in a third, to Southampton 

 in a fourth, to Plymouth, to Milford Haven, to Holyhead indeed, to 

 almost all our outports, and to nearly every inland town of any com- 

 mercial pretensions. A system is everywhere acted on, that the 

 principal railway stations shall at the same time be telegraph stations, 

 some of the wires being for public use, and the others for railway use. 

 The charges have been and are being gradually lowered, to the great 

 advantage of all parties ; and the messages now sent are of countless 

 variety the price of funds, the state of the markets, orders to purchase, 

 the arrival of ships, what ships have just hove in sight, what ships 

 have foundered, the receipt of important news, the Queen's speech, 

 the result of elections, the divisions in a debate, the running of a race, 

 the progress of the Court while travelling, the state of the weather, the 

 direction in which a great storm in travelling, the verdict of an 

 important trial, the sending for a doctor, the detection of a thief or 

 murderer, inquiries after health, announcements of illness or of death, 

 inquiries after lost luggage these are only some of the open or 

 confidential communications intrusted to the wires. Nor must we 

 forget the various submarine cablet, which although all have had 

 occasional mishaps, yet taken collectively afford a remarkably complete 

 cries of channels through which messages may be exchanged between 

 Great Britain and all the neighbouring countries ; and now the English 

 public hear with as little surprise of messages or teleyrana (to use a 

 new word, concerning which Greek scholars for a time carried on a 

 fieri. .light under water as if brought on dry land. 



On the continent of Europe we find telegraphic wires ramifying in 

 all directions. Nations were never more struck with the wonders of 

 the electric telegraph than on the occasion of the death of the Czar 

 Nicholas in 1855. On the 2nd of March the Karl of Clarendon announced 

 in the House of Lords that the Czar had died at St. Petersburg at one 

 o'clock on that same day. Two distinct messages had been received, one 

 rid Berlin and the Hague, the other rid Berlin and Ostend, both com- 

 municating a message telegraphed to Berlin from St. Petersburg, and 

 all in four hours after the actual death. Not only have the dreary 

 wastes of Russia been brought within the civilising influence of the 

 electric wire, but lines in all directions have been laid, with or without. 

 regard to railways. Nearly all the chief cities in Europe are now linked 

 her. Circuitous as is the route from London to Trieste, going 

 ii, Prussia, several minor German States, Saxony, 

 uia, Austria, and Istria, the connection is nevertheless complete ; 

 and telegrams are twice a-month transmitted to us relating to Indian 

 , brought to Trieste from Alexandria. Italy, in railways and in 

 telegraphs, is in arre;ir of Austria; and Spain is lower on the list than 

 Italy. Turkey, to the great astonishment of many of the Osmanlis, 

 has been made a sharer in the fast-going, high-pressure operations of 

 the age : she possesses an electric telegraph, extending from the 



Austrian frontier to Constantinople ; and messages can now be flashed 

 from London to the seat of the Ottoman empire. We have already 

 glanced at other submarine lines, and must now conclude. 



In sending messages in the United Kingdom by telegraph, either 

 cipher may be used, or the ordinary signals known at the Telegraphic 

 Office ; but such is the jealousy of despotism, that on the continent of 

 Europe cipher is never permitted, except by the governments for their 

 own use. 



An interesting use of the sub-way telegraph may be here noticed. 

 In proportion as the use of Greenwich time has become familiar on all 

 the English railways, so has it become important to ascertain this time 

 with precision, in such a way as to enable all the station-clocks to be 

 regulated thereby. This is one purpose of the time-ball in the Strand. 

 The Electric Telegraph Company, the South-Eastern Railway Com- 

 pany, and the Astronomer Royal, have acted in conjunction in the 

 establishment of this plan. A subterranean wire has been carried from 

 the Observatory, through Greenwich Park, and across Blackheath to the 

 Lewiaham station of the North Kent Railway ; thence to the London 

 Bridge station ; and thence to the Telegraph office in the Strand. At 

 the top of this office has been erected a hollow shaft, up the interior of 

 which the electric wire is carried, and a large light ball, capable of 

 moving eight or ten feet vertically, slides easily up and down near the 

 top of the shaft. At ten minutes before one o'clock each day the ball 

 is raised nearly to the top of ite shaft or spindle ; and at five minutes 

 before one it is raised quite to the top. At one o'clock precisely, 

 exact to a single second, the great or master-clock at Greenwich 

 Observatory puts in action a small piece of mechanism which sends an 

 electric shock through the wire to the Strand ; the wire at this end ia 

 connected with another piece of mechanism, which releases the ball 

 and allows it to fall suddenly. The ball falls upon a kind of piston in 

 an air-cylinder, so as to break the force of the concussion. As this 

 ball is 130 feet above the level of the Thames; as it is six feet in 

 diameter, exhibits bright colours, and falls through a considerable 

 space, its descent can be seen for a great distance on all sides ; and all 

 who choose to regulate their clocks and watches by this standard can 

 do so. An electric clock with four dials, illuminated at night, has been 

 put up on a pillar in front of the office ; it indicates Greenwich time 

 at all hours. The various railway stations receive their time from the 

 Strand office, which is the medium of communication from the 

 Greenwich Observatory. There can be little doubt that these arrange- 

 ments will contribute powerfully to the adoption of Greenwich time 

 in church clocks and other public clocks. So useful is this considered 

 to be, that a plan has been under consideration for erecting an electric 

 time-ball on the summit of the South Foreland ; the descent of such 

 a time-ball at one o'clock each day, could be witnessed by the captains 

 of ships many miles out in the Channel, who could regulate their 

 chronometers by this means, as the time-ball would show Greenwich 

 time. It was also proposed that the electric current should fire off a 

 gun at the same time and place, so that the sound might be heard if 

 the descent of the ball could not be seen. This proposal has actually 

 been adopted at Edinburgh and elsewhere. 



TKLEKYTHRIN. [LICHENS, COLOURING MATTERS OF.] 



TELESCOPE (from the Greek teUtcopnt, T7j\<rKciiros, " far-seeing"), 

 an optical instrument consisting of a tube which contains a system of 

 glass lenses having all then 1 centres in one common axis, or a tube 

 containing a metallic speculum in combination with such lenses : by 

 either kind of instrument distant objects are caused to appear magnified, 

 and more distinct than when viewed by the naked eye. Those which 

 are constructed with glass lenses only are called dioptrit, or refracting, 

 and the others catoptric, or reflecting telescopes. In the former kind 

 the rays in the pencils of light which come from every part of the 

 object viewed are, by the first lens on which they are incident, made 

 to converge so as to form an image at the focus of the lens. In some 

 cases the rays in each pencil are intercepted by a second lens, and, by 

 its refractive power, are made to enter the eye in parallel directions : 

 in other cases, the rays, after having crossed each other at the place 

 where the image is formed, fall in a divergent state upon a second lens, 

 and by it are refracted so as to emerge from it in parallel directions. 

 Frequently, however, the parallelism of the rays is effected by two or 

 more lenses in addition to that, called the object-glass, by which the 

 image was formed. In reflecting telescopes an image is formed by the 

 reflection of the rays in the pencils of light coming from the object, after 

 having impinged upon the concave surface of the speculum : in some 

 cases this image is viewed through one glass lens or more, but frequently 

 the rays, before or after forming the image, are reflected from a second 

 minor, and are subsequently transmitted to the eye through lenses. 



By these instruments objects even in the remotest depths of space 

 are rendered accessible to human vision ; and terrestrial objects faintly 

 visible in the. distance are brought, as it were, close to the eye. In the 

 hands of astronomers they were the means, almost immediately on 

 being invented, of making more discoveries in the heavens than had 

 been made during 5000 years previously ; they form a valuable addi- 

 tion to the instruments employed by the mariner and the surveyor, 

 and they will ever constitute the most agreeable companion of the 

 traveller, by enabling him to distinguish, in every direction from him, 

 objects which it might be difficult or impossible for him to approach. 



In exhibiting the principles on which a telescope is constructed, it 

 will be proper to commence with an explanation of the means by 



