1841.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL 



175 



An electric glow or " brush " is effected at the place required to be lighted, 

 and being placed in the focus of reflectors, yields rays of light, which may be 

 made revolving liglits for night signals, cite. 



la addition to tlie numerous improvements iucluded in this specification, 

 already noticed, tliere is one for a fire-engine to be worked liy the " gaso-pneu- 

 matic power," to lie drawn from the gas mains in the streets where the fire 

 occurs, in the same manner as the water. [This specification occujiies fifteen 

 sheets of parcliment, and there is also a corresponding number of drawings.] 

 —^l7iveiifo7'^s Advocate. 



STEAWS. NA VI CATION. 



THE NIGER EXPEDITION. 



The expedition about to leave this country, to explore the River Niger, 

 and wliich has excited such intense interest, cousists of three iron steam 

 Tessels under the command of Captain Trotter, an intelligent and experienced 

 officer of Her Majesty's navy. The two larger ones, the "Albert" and the 

 " Wilberforce," are each of 440 tons burtlien and 70 horses' power ; and the 

 smaller one, the " Soudan," (intended to act as a pilot vessel,) admeasures 

 250 tons, and has an engine of 35 horses' power. 'The two first are schooner 

 rigged, and are remarkably fiue-looking vessels, with lofty spars, and will 

 display a large spread of canvass to the favouring breeze. Tlicy are fitted 

 with Captain George Smith's method of stowing boats to form part of the 

 paddle boxes, in addition to the usual complement of boats. They are 

 heavily armed, and will each carry a number of Kroomen (a class of men ac- 

 customed to the cbmate, and found to be of eminent service), besides an efli- 

 cient man-of-war's crew ; and altogether, will prove formidable opponents 

 should the natives venture to molest them, as they did the last expedition, 

 under Messrs. Laird & Oldfield. 



The interiors of tlie steamers are replete with every convenience, and even 

 luxury, which can be desired. Tliey are furnished with Dr. Eeid's ingenious 

 system of ventilating tubes (a kind of air filter) for the purpose of supplying 

 fresh air in the 'tween decks ; and whicli contrivance, it is confidently ex- 

 pected, will prove of great utiUty in protecting the crews from the debili- 

 tating effects of the noxious vapours whicli infest the vicinity of the River 

 Niger, and which have hitherto rendered that climate so dreadfully fatal to 

 Europeans. From tlieir light draft of water they will be enabled to ascend 

 a considerable way up the river, should they be so fortunate as to escape 

 nmning hard aground, as from their great size it would be a difficult matter 

 to get them off, especially should the crews suffer from the climate. Tlie 

 last expedition incurred great delays from the vessels continually getting 

 aground ; yet tliey were much easier got off than these would be from their 

 being of smaller dimensions. 



In conclusion we wish them every success, and must say that an expedition 

 better calculated to fulfil its purpose never left the shores of this, or, indeed, 

 any other country. 



A comparison of the dimensions and draft of water of the steamers com- 

 prising the last and present expeditions, may afford an idea of the advanced 

 state of steam naval architecture since the year 1832. 



The vessels of the present expedition were built by Mr. John Laird, of 

 North Birkenhead, Liverpool, and the engines by George Forrester & Co., 

 of Liverpool. 



Ainiliary Sleam Pouvr. — M'e liave to announce the departure for India, 

 during the last month, of the " Isabella Blyth," a ship of 500 tons burden, 

 fitted with a pair of small engines and paddle-wheels, to be used during 

 calms and light «inds, vihich, it has been ascertained on statistical data, 

 prevail, on an average passage to or from India, during full one third of the 

 time occupied by the whole voyage. To overcome this very serious ilifficully. 

 and ensure regular and rapid passages, the splendid class of vessels which 

 now conslitulc our mercantile navy, appear to require nothing more than the 

 successful application ol steam power as an auxiliary. In order to prevent 

 the great loss of power and increased liabi'ity to derangement resulting from 

 one paddle wheel being immersed too deeply in the water u hen the ship is 

 listed over, (whi'e the other would consequently be entirely cut of the water.) 

 and also to elevate and depress the paddle wheels to suit the immersion of 

 the vessel, which will, of course, vary not only with difierent descriptions of 

 cargo, but a'so by the consumption of fuel, water. Sec, during a voyage ; the 

 paddle wheels are fitted in such a manner that either wheel may, by the 

 power of one man, be raised or lowered as occasion may require without stop- 

 ping the engine'. The greatest advantage w ill thus be taken of every breeze 

 of wind, without any sacrifice of the auxiliary power. We feel assured that 



the ordinary paddle wheels which h ive, up to the present time, proved su- 

 perior to every other propeller, only required this adaptation (o render their 

 application to sailing vessels perfect, and we therefore anticipate a very 

 favourable result. 

 _This vessel left the London Docks the latter part c,f last month, drawing 

 17ft. Bin, water, and after encountering more than the usual obstructions of 

 tlie Pool, and proving in all her movements to be completely under tlie con- 

 trol of the steam power, the paddle wheels were adjusteil to the proper 

 depth of immersion, and the distance to Gravesend was performed in about 

 four hours and a half. With the exception of a topsail being set during 

 about tw enty minutes, no ailvantage was taken of the sails. 



Bistiiigiiislihig Signal/or Steam Boats. — We have been gratified, in common 

 with a considerable number of steam-boat owners, captains, and others inte- 

 rested in steam navigation, by being shown a signal which will most admi- 

 rably eftfct an object most desiderated, that of distinguishing sleam vessels 

 from sailing vessels at sea. and go far to prevent unhappy collisions and the 

 destruction of human life. The inventor is Mr. Francis Melville, Buchanan 

 Street, who. from a praisew orthy desire to promote the general safety, has 

 devoted much of his time to the subject. Mr. Melville's plan is to place in 

 front of the funnel of the steamer a lamp, with a clear light, and a strong 

 reflector, having an external sliding cover attached to its face, so fitted as 

 CI mpletely to oDscure the light within, but to be made to move up and down 

 the w hole length of the lanthern, by means of a rod affixed to a small lever 

 power connected with the engine, so that the motion or alternations of the 

 slider w ould be at the rate of twenty in a minute. At the bottom is to be 

 added a flat sole, made so as to carry the rays of light completely over the 

 side of the vessel, in order that the reflection from any object on deck may 

 nut interfere with the pilot. By means of this simple apparatus, a signal will 

 be produced perfectly distinct from any other known in navigation, and by 

 means of it a steamer will, at the first sight, be known from any other vessel. 

 Though the exhibition which we had the opportunity of observing was neces- 

 sarily imperfect (being displayed from a window), enough was, nevertheless, 

 witnessed to show at once the perfect practicability and adaptation of the 

 signal to the purpose intended. — Glasgow Argus. 



.Sixteen tvar-steamcrs are ordered to be built, six of tlie first class and ten of 

 the second ; all to be armed with guns of 10 inch calibre. Several of these 

 w ill be laid dow n immediately, and the frames of the w bole converted with- 

 out delay, so as to he ready against the engines are prepared. — Naval and 

 Militari/ Gazette. 



The Royal West India Steain Xavigation Conipani/ have resolved to build six 

 additional steamers. From the high recommendation given to the Clyde 

 ship-buililers by the Government inspectors, who have inspected the steamers 

 now on the stocks, we understand that a few. if not the whole, of the addi- 

 tionil steamers will be constructed on the banks of the Clyde. Three addi- 

 tional steamers are about to be contracted for by the Cunard Atlantic Steam 

 Company. — Glasgoiv Vlironiele. 



y/ie .1/ammo/A, building by the Great Western Ship Company, at Bristol, 

 will exceed 3, GOO tons (about 6U0 more than any otlier ship in existence). 

 The saving of room by her being built of iron will admit of her carrying coals 

 for both the outward and home voyages, a matter of mueli importance from 

 the interior quality of American coal. Her engines are of 1.000 horse power. 

 She will be enabled to c.Trry an unusual quantity of canvass, and is expected 

 to make the passage of the Atlantic in ten days. — Liverpool Advertiser. 



niISCEI.I>ANEA. 



The Duke of Wellington's St.4tue. — This colossal equestrian figure 

 is rapidly progressing under the hands of Mr. Wyatt. When completed, it 

 is expected to weigh about 50 tons, and to stand about 32 feet from the 

 pedestal. If possible, it is to be formed entirely of the cannon taken by his 

 Grace. The model of the horse, which is about half finished, is very fine. 

 The gigantic animal, with eyes extended and nostrils inflated, is breathing 

 with animation and vigour. The head and boots of the Duke are already 

 cast. The face is an admirable likeness, as is well known to all who had an 

 opportunity of seeing the model of it last year. These parts of the figure, 

 which are all at present completed, have taken the metal of a single cannon. 

 The lower extremities of the figure will be of solid bronze, the thickness gra- 

 pually diminishing in the upper parts. It is said that the committee have 

 appointed two years as the period in which the work should be completed, 

 11 months of which have already transpired, but it seems almost premature 

 to fix a time for the finishing so elaborate and gigantic a work, especially 

 when the process of casting is attended with so many risks that may cause a 

 temporary impediment to its progiess. During his labours Mr. Wyatt has 

 acquired much valuable experience calculated to advance the art of casting 

 in met.al, among which are a method for testing the tubes which supply the 

 metal to ascertain that they are perfectly clear, and a plan with the air tubes 

 that causes them not only to expel the air, but also to operate as suction 

 tubes to the metal, and promote its distribution. Another ingenious contri- 

 vance is a set of instrumeuts, invented by Mr. Wyatt, for clearing off the 

 metal with infinitely less labour than a common hand-instrument. This M'el- 

 lington statue, when finished, will, it is supposed, be the largest hitherto 

 known. 



Primrose Hill, Regent's Park.— The Commissioners of Woods and Forests 

 have, we understand, concluded an arrangement with Eton College, by which 

 Primrose-hill will be preserved from being built upi n. This place of health- 

 ful resort will therefore remain to the inhabitants of the metropolis, as one 

 of the " lungs of London." 



