ISlt.J 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



383 



and the wood at Southend. The operations of the Teredo, although most 

 desinictive in warm eliiiiaies, extended themselves to all places, having 

 been found almost in the I'olar seas. 



Tiie chief periiliaiities which distinguished the Teredo were stated to 

 have been a^ce^l;lin•'d by minute microscopical investigaiiou, and that 

 woody libres of an extremely minute nature had been discovered in ihe 

 body, tlius setting at rest the question as lo wlielher the Teredo (i\<i actually 

 feed upon the wood. It was stated, that the failure of chemical means to 

 preserve timber from destruction by the marine worm was believed to pro- 

 ceed from two causes — namely, of poisonous compounds having no se- 

 riously injurious etl'ect upon them, and the sea-water, and other things, de- 

 composing the poisonous ingredients contained in the wood. In corrobo- 

 ration of the first of these views, accounts of experiments made by Mr. 

 Paton were adduced ; and physiological facets, quoted from the British and 

 Foreign Medical Review, were brought forward to show, lliat cold-blooded 

 anlnials were much more tenacious of life, than those of a higher tempera- 

 ment; and hence it was argued, that, as it required a very large quantity 

 of poison of the most virulent nature, to destroy animals of a much higher 

 order than the Teredo Navatis, it would take a still greater quantity to 

 att'ect those animals as they existed in their own element ; and it was ques- 

 tioned, under these circumstances, whether wood could ever be so com- 

 pletely auil thoroughly saturated, as in any degree to all'ect them. The 

 C( rrosive action of tlie sea-water, its extended influence and constant vari- 

 ableness in difVerenl parts of the globe, were then coiiujieuled on, and some 

 of the various salts held in solution nieutioned. It was believed to be im- 

 possible to lorm any general notion of the precise action of sea-water on 

 timber, whether chemically saturated, or not, without a series of most mi- 

 nute experiments, and a large body of facts, carefully collected in different 

 parts of the globe — as that which might be advantageously used in the 

 Thames, might not be of the slightest avail in the Tropics, and vice versa ; 

 it was thus questioned, whether any generally applicable principle could 

 be found for the counteracting of that universal solvent of soluble matter. 

 The conclusions arrived at were, that the ravages of the marine worm were 

 not prevented by any chemical application, and that nothing but mechani- 

 cal means could ever prove completely successful : studding with broad- 

 headed nails was considered to be the most effectual remedy, and various 

 authorities were quoted, proving its success. The paper concluded with 

 a list of places where wood, prepared with various chemical ingredients, 

 had been destroyed from various causes. 



The discussion was commenced by the Dean of Westminster who 

 descanted very lengthily uu the analogous action of the Pholas ou stone, 

 and uu other topics, until, as the evening was so far advanced, it was an 

 uuunced that the discussion on the paper would be continued at the next 

 meeting, December 4, when the first muothly ballot would take place. 



NOTES OF THE MONTH. 



The Royal Yacht. — The Victoria and Albert is ordered to be docked at 

 Portsmouth to have an entire refit, and to have new boilers planned for her. 

 This «ill be the third set of new boilers within five years, although she is 

 only employed about a month each year. When this vessel was launched we 

 estimated the cost at 100, OUO/. The idea was then scouted, but it is never- 

 theless the fact that she has cost the country altogether nearer 200,000/. We 

 are quite sure that the public would not begrudge the expenditure of the 

 larger sum in procuring for her Majesty a suitable yacht, if the accommoda- 

 tion could not he obtained for a less amount, but they will object to paying 

 for one most inefficient vessel what ought to purchase at least half a dozen. 

 The Ruler of Egypt has degraded and banished the naval architect and cap- 

 tain of his yacht — a good and etficient ship many hundred tons larger than 

 the Victoria and Albert — because the cost exceeded the estimate ; but our 

 liberal and enlightened government has given the naval architect of the 

 Royal yacht a retirement of 500/. a year, whilst his assistant has had his 

 salary increased from 650/. to 800/. a year, and the shipwright, builder, and 

 his progeny have received all sorts of promotions. People of comiiion sense 

 will easily determine which government is most wise and just. — United 

 Service Gazette, 



Parachute Lights. — Snme experiments were recently made at the Wool- 

 wich Mortar Battery, to test the efficiency of a new light invented by Capt. 

 Boxer, for lighting the atmosphere. General Lacy, Col. Dundas, C.B., 

 Lieut.-Col. Chalmer, Lieut.-Col. Bell, Lieut.-Col. Brereton, C.13., Lieut. -Col. 

 Hardinge, K.ll., Lieut.-Col. Anderson, Lieut.-Col. Pester, Lieut. Col. Max- 

 well, Brigade-Major Bingham, and Major Dupins, with a great numlier of 

 officers ot the garrison, and Lord James Hay, assembled at the Mortar Battery, 

 when quite dark, to witness experiments with the common 8 inch carcases 

 of the service, used for firing so as to give light to show the position of an 

 enemy in dark nights, itfid to compare them with an invention to answer the 

 same purpose more effectually, invented by Capt. Boxer, Royal Artillery. 

 The first fired was one of the carcases from an 8. inch mortar, and it fell to 

 the ground at a distance of between 200 and 300 yards, and continued 

 burning aliuut 10 minutes. One of the cases containing Capt. Boxer's plan 

 was then fired. It consists of two tin cases, each being half-a sphere; the 

 one containing the composition, which Iiuriis like a brilliant blue light, and 

 the other, the parachute, formed uf a light description of closely-woven 



bunting. The diameter of the cases appeared to be about five inches, and 

 when fired they attained a considerable altitude, hut the parachute did not 

 in the first instance open out sufficiently, and the lighted composition soon 

 fell to the ground. The second fired ou Capt. Boxer's plan was a beautiful 

 spectacle, the shells ascending to a great altitude, and when at the highest 

 point an explosion took place, similar to the bursting of a rocket in the air, 

 and out came a parachute fully 6 feet in diameter and about 3 feet in depth, 

 suspending the brilliant blue light and gradually descending, illuminating 

 the pait of the common on which it descended with a very brilliant light. 

 The third and fourth — all that were fired on Capt. Boxer's principle — were 

 equally successful, and all appeared much gratified with the result. Three 

 other carcases were fired from the 8-inch mortar with a similar effect to the 

 first ; but although they gave out flame for a considerable time, they ap- 

 peared to burn dim compared with Capt. Boxer's. It may be mentioned 

 tbat the parachute which supports the burning composition, on Capt. Boxer's 

 plan, is about from 7 to 8 feet above the burning matter; six curds descend- 

 ing from it are attached to a small chain about a foot lung, fixed to the com- 

 position shell. 



Poor rates in the Metropolis. — It appears from an ingenious work recently 

 published by Mr. G. L. Hutchinson, that the following inequalities exist in 

 the rating of the metropolis, which is by no means the worst instance to be 

 adduced : — The annual value of property in East and West London is 

 211,150/., rated at 2s. lOrf. in the pound. The annual value assessed in the 

 City is 613,883/., rated at Is. Id. ; Whitechapel, 197.522/., rated at Is. 9rf. ; 

 St. James's, Westminster, 250,160/., rated at lOrf. ; Bethnal-green, 05,549/., 

 rated at 2s. 9rf. ; St. George's, Hanover-square, 601,105/., rated at dd. The 

 amount received by the poor of the city is equal to 18s. lOrf. per head on 

 the population within the walls, and the amount of relief given to the po- 

 pulation without the walls is equal to 8s. dd. per head. The amount of re- 

 lief extended to the poor of the different districts per 1/. value of rated pro- 

 perty is — Bermondsey, 3s. id.; East and West London, 2s. IQd. ; Bethnal- 

 green, 2s. 9(/. ; St. George's, Southwark, 2s. id. ; Shoreditch, 2s. id. ; 

 Greenwich, 2s. id. ; Newington, 2s. id. ; Stepney, 2s. ; Rotherhithe, Is. lid. ; 

 Whitechapel, Is. 9rf.; Camberwell, Is. 8<f. ; Holborn, Is. 'id.; St. Luke's, 

 Is. Id.: City of London, Is. Id.; Hackney, Is. hd.; Strand, Is. hd.; Cler- 

 kenwell, Is. 4d. ; Poplar, Is. 3(/. ; St. Giles, Is. 3d.; Kensington, \s.\d.; 

 St. Pancras, Is. Id.; Westminster, lid.; Marylebone, lid.; St. Martin's- 

 in-the-Fields, lid.; St. James's, Westminster, lOd.; Islington, 8d. ; and St, 

 George's, Hanover-square, 6d. These disproportions have rather increased 

 than diminished since this return was made. 



Chlurure of Silver. — Ilerr Poggendorf has succeeded in decomposing 

 chlorure of silver by the galvanic battery, which is useful when it is wanted 

 to prepare pure silver to re-dissolve it. The way is, to take chlorure of 

 silver in the wet state, put it in a crucible, pouring over diluted sulphuric acid 

 (1 acid,9-water), and introducinga porous cylinder filled with the same liquid, 

 and in this a plate of amalgamated zinc, brought into communicaiton by a 

 copper wire with platinum or silver. 



Profits on Gas Manufacture. — A statistical return of the outlay and 

 profits of the Durham Gas Company shows tbat their gains for the year 

 1848 were at the rate of 27t per cent. 



On the Duration of Wood, and Means of Prolonging it. — The following 

 are the results of experiments made with great care and patience by Mr. G. 

 S. Hartig : — Pieces of wood of various kinds, 25-8th inches square, were 

 buried about an inch below the surface of the ground, and they decayed in 

 ihe following order : — The lime, American birch, alder, and the trembling- 

 leaved poplar, in three years; the common willow, horse-chesniit, and plane, 

 in four years ; the maple, red beech, and common birch, in five years ; the 

 elm, ash, hornbeam, and Lumbardy poplar, in six years; the robinia, oak, 

 Scotch fir, Weymouth pine, and silver fir, were only decayed to the depth of 

 half-aninch in seven years ; the larch, common juniper, red cedar Quniperus 

 virginianaj, and arbor-vilse, at the end of the last-mentioned period re- 

 mained uninjured. The duration of the respective v\oods depends greatly 

 on their age and quality ; specimens from young trees decaying much quicker 

 than those from sound old trees ; and, when well seasoned, they last much 

 longer than when buried in an unseasoned state. In experiments with the 

 woods cut into thin boards decay proceeded in the following order, com- 

 mencing with the most perishable order : The plane, horse chesnut, poplar, 

 American birch, red beech, hornbeam, alder, ash, maple, silver fir, Scotch 

 fir, elm, Weymouth pine, larch, robinia or locust oak. It has been proved, 

 by repeated experiments, that the best mode of prolonging the duration of 

 wood is to char it, and then paint it over with three or four coats of pitch. 

 But simply charring the wood was of very little utility, as were also satura- 

 tions with various salts, acids, &c, — Revue Horticole. 



Expansive Steam- Engines. — Mr, J. C. Fearce, of Salford, has made aa 

 improvement in the expansive steam-engine, the advantages contemplated 

 by which are stated to consist in the application of two self-acting valves, 

 in addition to the expansion legulalor, one lo each end of the steam 

 cylinder — fixed in suitable passages, which communicate with the waste 

 steam or exhaust pipe, Mr, Pearce states that the use of these valves is 

 to prevent the pressure upon the working side of the pistou from falling 

 below the resistance or back pressure upon the opposite side — a very com- 

 mon occurrence in carrying out the expansive principle, although attended 

 with very considerable loss of power ; and that the proposed improvement 

 is chiefly adapted to locomotives and other nou-coudcnsiug expansive en- 

 gines, and the power is extremely variable. 



