358 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[October, 



The caisson, which is of cast iron, is 30 feet in diameter at the base, 

 and is of a conical form, diminishing upwards 1 in 5. It is formed of a 

 series of plates, with flinches at the joints 3 inches in width, and con- 

 nected together by 4 inch wrought iron bolts. Each tier of plates is 

 6 feet in height ; the lower tier is U in thickness, the circumference 

 is divided into 24 plates as are the other (3burses above, which are 

 respectively arranged so as to break joint. Within the lower tier the 

 working chamber is constructed, in which the process of excavation 

 will be carried on as in a diving bell, and the spoil discharged through 

 a 4-feet aperture in the centre of its domed top into the second cham- 

 ber. The chamber above is fitted with air-pumps, gauges, and appa- 

 ratus for regulating the supply of air to the workmen in the working- 

 chamber; and from the second chamber proceeds a 4-feet cylinder 

 extending upwards through the centre of the caisson for the further 

 discharge of spoil. The height of the chamber above will be regu- 

 lated by the depth to which it may be necessary to proceed before the 

 chalk is arrived at, plates being added to the caisson as its descent is 

 effected through the sand. By means of valves and man-holes, &c., 

 the two lower chambers communicate with each other as far as it is 

 necessary for the supply of air for the workmen, and the discharge 

 of the sand during the process of excavation, which will be carried on 

 from within, similar to the sinking of a shaft or the kibt of a well, the 

 lower chamber acting in this respect as a diving bell, by which the 

 work is carried on under water, and through the cylinder at stated 

 periods, when external communication is cut off' from the lower cham- 

 ber, the spoil will be discharged into the sea. The caisson has now 

 descended 24 or 25 feet in the sand, or about 30 feet below low water 

 mark ; the tide rises about eighteen feet, and from various indications 

 combined with the general stability of the machine, it is presumed to 

 rest at present near the solid chalk. When the caisson shall have been 

 brought upon a level bed, and the sand excavated, the interior will be 

 filled up with solid masonry and concrete, upon which foundation the 

 light-house is proposed to be erected. 



PATENT RELIEVO LEATHER HANGINGS. 



We feel much pleasure in directing architects to the veiy great improve- 

 ments made iu Messrs. Leake aud Co.'s Patent Relievo Leather hangings, 

 panels, imitation oak carvings, Ac, of which they have an endless variety at 

 their offices, 52, Regent-street. Her Majesty and H.R.H Prince Albert have 

 more than once had a large variety of patterns sent to Buckingham Palace 

 and Windsor Castle for their inspection ; aud have shown their excellent 

 taste in selecting many beautiful examples, for decorating step of the state 

 apartments hotli at Windsor and Buckingham Palace. The designs are very 

 beautiful ; indeed it is difficult to discover that some of the patterns are not 

 carvings in xoood — so closely imitated are the chisel marks, the grain of the 

 wood, the undercutting, and its assimilation of colour to the best oak and 

 walnut carving of the middle ages. The hangings, friezes, heads, fruits, &c., 

 in the various rich and elaborate styles of decoration prevalent in Spain, 

 Italy, France, and Germany, as well as our own Eliazbethan, are here 

 brought to their greatest perfection, and will bring about a decided improve- 

 ment in our present mode of decorating public buddings, the baronial resi- 

 deuces of our nobility, churches, &c. The cost of these ornaments is about 

 half the price of carvings in wood. 



IMPROVEMENT IN COATING OR COVERING METALS. 



Mr. Henry Fox Talbot, of Laycock Abbey, Wilts, has obtained a patent 

 for improvements in coating or covering metals with other metals, and in co- 

 louring metallic surfaces. — They are four iu number. The first consists in 

 adding gallic acid to the metallic solutions intended to be preciptated. Any 

 convenient solution of sdver, gold, or platina is taken ; and to each of them 

 is added a solution of gallic acid, in water, ether or alcohol, (the last being 

 preferred.) Into any one of these mixtures a clean bright plate of metal is 

 immersed until it becomes coated with silver, gold, or platina, as the case 

 may he. A weak or dilute solution is recommended to commence with, and 

 afterwards a stronger one. The acid need not be pure. The second is a 

 method of silvering metallic surfaces. Freshly precipitated chloride of silver 

 ir dissolved in hyposulphite. Into this solution a clean bright plate of metal 

 is immersed, and becomes very quickly coated with a bright sUver coating. 

 To obtain thicker coats of metal, a gilvauic battery is employed, using one 

 of the liquids before described, and lakingfor one of the poles a piece of 

 metal of the same kind as that intended to be precipitated. The third is a 

 method of ornamenting surfaces of brass or copper, by first gilding them par- 

 tially, according to some pattern, and then washing them over with a solution 

 of chloride of platina, which gives a dead black appearance to the rest of the 

 surface, and enhances the brilliancy of the parts gilt. The fourth is a method 

 of colouring polished surfaces of copper, by exposing them to the vapour of 

 sulphuretted hydrogen, or any of the liquid hydrosulphurets, or to the vapours 



of sulphur, iodine, bromine, or chlorine, or by dipping the metals into liquids 

 containing them. The claim is to the use of the galhc acid, or any liquid 

 containing it, or any analagous vegetable substance for facilitating the preci- 

 pitation of metals \ipon other metallic surfaces, and coating them therewith 

 — to the use of bydrosulphate of soda for the silvering of metals, and the 

 employing a galvanic battery for obtaining thicker deposits of silver, gold, or 

 platina, but only when used iu conjunction with one of the liquids so de- 

 scribed : and to the colouring of copper surfaces by exposing them to the 

 chemical action of the above-named substances. 



IMPROVEMENTS IN DAUGUERREOTYPE. 



M. Claudet, of High Holborn, and Adelaide Gallery, has obtained a patent 

 for improvements in the process for obtaining images or representations of 

 nature or art. They are five in number. The first consists in making in the 

 front of the camera obscura an aperture large enough to admit object glasses 

 of various foci, so as to have either large or small plates, and obtain images 

 of near or distant objects. The second consists in substituting for the de- 

 tached mercury box ordinarily employed, a cup of mercury placed within the 

 camera, and heated by a spirit lamp till the mercurial vapours rise and fill the 

 camera. The light and mercury are made thus to act simultaneously on the 

 plate, whereby a more intense and perfect image is obtained. In the side of 

 the camera there is an eye- hole, covered with red or orange-coloured glass, 

 through which the operator may watch the process, and be thus enabled to 

 withdraw the plate the instant the proper effect is produced. The third con- 

 sists iu placing immediately behind the sitter for a portrait, painted back 

 grounds or scenes, representing landscapes, interiors of apartments, &c., which, 

 being thus brought within the range of the Dauguerreotype apparatus, are 

 transferred to the plate, as well as the portrait of the sitter. The fourth con- 

 sists in the employment, in the absence of daylight, of an artificial light, pro- 

 duced either from the combustion of coal, promoted by a jet of oxygen gas, or 

 from combustible gases aud carbureted liquids burning together with oxygen : 

 or from a solid refractory body suspended iu a jet of inflammable gas, &c. 

 Care must be taken that the burner is fixed exactly in the axis of the reflect- 

 ing minor, or that the greatest Ught falls on the centre of the curve. The 

 fifth and last improvement consists in performing the whole process in a 

 lighted room instead of in the dark, as has been hitherto the case. A white 

 light must, however, be avoided, and screens of red, orange, green, or yellow, 

 are therefore employed. Of these colours red is preferred, as having the 

 least injurious effect on the plates. 



A New Forging Machine. — This machine for the working or forg- 

 ing of iron, steel, &c., is quite portable, occupying only a space of 3 feet by 4 

 feet, and cannot be deemed other, even by the most crit cal judges than one 

 as purely original in principle, as well as practical in its application. It may 

 he worked by steam or water power, and when moved by the former at an 

 exhibition it made C50 blows or impressions per minute ; but from their 

 very quick succession, and the work being efl'ccted by an eccentric pressing 

 down, not striking the hammer or swage, not the least noise was heard. 

 There are five or six sets of what may be called anvils and swages in the 

 machine, each varying in size. The speed and correctness with which the 

 machine completes its work, is perfectly astonishing, and must be seen in 

 order that its capabilities in this respect may be duly appreciated : for in- 

 stance, when it was put into motion for the purpose of producing what is 

 known as a roller, with a coupling square upon it, (and which had to be 

 afterwards turned and fluted,) the thing was accomplished in fifty seconds ! 

 of course at one heat, to the astonishment of the bystanders. But what ap- 

 peared as the most extraordinary part of the afl'air, was, that the coupling 

 square was produced dbect from the machine, so mathematically correct, 

 that no labour can make it more so ! The machine will perform the labour 

 of three men and their assistants or strikers, and not only so, but complete its 

 work in a vastly superior manner to that executed by manual labour. For 

 engineers, machine makers, smiths in general, file makers, bolt and screw 

 makers, or for any description of work parallel or taper, it is most specially 

 adapted ; and for what is technically known as reducing, it cannot possibly 

 have a successful competitor — in proof of which it may be stated, that a 

 piece of round iron 1 j inch in diameter, was reduced to a square of % in., 2 

 ft. 5 in. long, at one heat. The merit of this invention belongs, it is said, to 

 a gentleman at Bulton, of the name of Ryder. — Leed's Mercury. 



Improveo Door Knobs. — A patent has been obtained bv Mr. Daniel 

 Greenfield of Birmingham for improvements in manufacturing hollow metal 

 knobs for the handles of door and other locks ; the essential character of the 

 improvement being that of forming an interior lining of stamped iron-plate 

 to the hollow-ball part of the knob, and (in case it is preferred) an interior 

 of cast-iron to the neck part of the knob, in order, by means of such 

 stamped-iron and such cast-iron (if the latter be used) to give support to the 

 brass, German silver, or other metal, whereof the exterior surface of such 

 knob is or may be composed." 



