]C,-2 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Mat, 



bands of wroiiglit iron. The ciiuin is of wroiiglit iron, ami (lie rings 

 may \ic made eitlier of wrought or cast iron. Tlie hollow cylinders 

 are for the jjurjiose of producing ligtitness in the upper line, which is 

 essential. 



FiK. 4. 



The application of this system to roofs and floors is extremely eco- 

 noniiral and iispfnl, and liy simple inodiliraliuns serves for the covering 

 of large spuves uithoiif any inlernipdiate point, of support, and pre- 

 sents this fnrther advantage, thai from its vertical pressure it requires 

 no other support than walls of moderate thickness. 



When applied to floors, bridging joists will remedy the inerpiality of 

 surface in the beam itself. 



In roofs of large span the posts may be continued up so as to receive 

 the purlins, and when continued downwards serve to hold up the ceiling, 

 whether Hat, or vaulted, or mixed. 



The principal rafters of a roof may derive considerable strength 

 from being treated in the same way as in fig. '2, which combination is 

 calculated for roofs of 50 feet span ; by this arrangement of the prin- 

 cipal rafters at distances of lU feet apart, no intermediate stays or 

 posts are necessary to support the purlins, so that a fine clear span 

 space is left in the roof. Here the tie beam is slit according to Mr. 

 l.aves' system, and acquires snflicient strength to support itself without 

 being tied up to a truss. 



Mr. Laves has applied this principle to various roofs. 



<")ne in iron over the kitchen in the Royal Park at Hanover ; one in 

 carpentry of .'>(! feet span, over a barn belonging to tlie Baron of Wan- 

 genhcim, at Wangenheim, uearGotba; and likewise one at Hersuni, 

 near Hildesheim, and over the scenery magazine o^' the theatre at 

 ilanover. 



'J'he painting room of the scenery in the theatre at Hanover has the 

 slope of the roof formed by rafters, slit down the middle and kept apart 

 . — the span 3b feet in the clear, and length 74 feet. 



Anollier application of this system is to large ladders, which when 

 very long, whether used for fires, to scale batteries of beseiged towns, 

 or to board ships, had the inconvenience of being cumbersome, difficult 

 of conveyance from one part to another, so that they I'ould be managed 

 only by numerous assistants; hence they were comparatively little 

 serviceable for the end proposed, and frequently not able to bo brought 

 in tiuic suflii'ient to render the assistance required. 



In the case of ladders each of the sides of tlie ladder is sawn in two 

 to within a certain distance from the ends, which are bound together 

 liy iron l)olts or straps. The intermediate stays, used to keep open 

 the cut, also serve to combine the forces of the two jiarls, and being 

 continued are useful to receive a side cord, as an addilioiral security to 

 a person ascending or descending. A ladder so constructed may be 

 jilaced in a horizontal position, and is sufficiently stiff' to act as a tem- 

 porary bridge or scaffolding, from the window of one house to tliat of 

 another on the opposite side of the street, or from one vessel to 

 another. 



If the chain be formed of iron wire, it would answer the purpose 

 ecpially well, and be tighter. 



If it be desirable to place the ladder in a slightly inclined direction, 

 without any iunnediate object to rest against, two props or supports 

 should be placed against the u|)j)ermost rail or round, which, to .ivoid 

 osciliation or beniUng, should also be composed of slight pieces of 

 timber, sawn down the centre, kept apart by small intermediate blocks, 

 and bound at tlie ends as already described. 



Mr. Moore's pati;nt Pr.AN for FErniNc, FrRN.'CKs, J^c. Fmus, Foa 

 THK Consumption of Smokk. — Mr. Moore proposes to have the gr:i1c-liars 

 hollow sciiii-oylinilers, with the concavities upwards. The fuel is put into a 

 similar scmi-cylindcr scoop cap:il)le of sliding within eitltcr of the gralc-bars, 

 and being llii'iist in from end to end, is turned half round, and then with- 

 drawn, leaving the fuel in the same cylinder bars, whicli is ignited from the 

 burning coals aliove. Tlie patentee says he has never found ain' ditficiilty in 

 the scoop's forcing out tliebnnit fuel already in the gralchars, and that the 

 fire, tiy this contrivance, never wants any more stirring tliaii is given by the 

 introduction of the new fuel. Of course, tlie smoke is ignited and consumed 

 by passing up through the red-hot coals above. — Ra'duay iluguzine. 



STEAM NAVIGATION. 



Tiiii bold front shown by the Engineers and Steam .Ship Builders, 

 lias shaken Mr. Labouchere's confidence in the propriety of tlie mea- 

 sure of which he is the official custodian, and, like a prim old maiden 

 distrustful of the legitimacy of the little darling which she had been 

 parading with so much delight, is prepared to modify bis trust. He 

 expiesses his hope that the measure, as modified, will contain nothing 

 distasteful to the engineers, and appears extremely anxious not to go 

 at once into a discussion on the grievance. \V'e hope that the engi- 

 neers will think as we do, that this is not a question to lie compro- 

 mised, nor is it prudent to allow such a threatening attack to pass 

 without notice, for the animus is too evident not to render the intro- 

 duction of the bill certain, whenever its concocters can watch a fitting 

 opportunity; we therefore warn all concerned to be prepared at a 

 moment's notii^e to ojipose this obnoxious measure. 



We have felt ourselves strengthened in the course we have adopted, 

 in the consideration of this momentous questimi, by an able memorial 

 which was addressed to Congress in February last, by the proprie- 

 tors and managers of steam-boats in the United States, who, so far 

 from concurring in the wisdom, even of the modified code brought for- 

 ward as an example by our roinmissioners, boldly declare its injustice 

 and inefficiency. Fearless of al. the exaggerated horrors of news- 

 pa]ier paragraphs, and of the facts and pseudo ficts raked up by 

 government authorities, they claim at once for steam navigation "a 

 degree of security in the transportation of persons and property, 

 which has not been equalled by any other known means of transport 

 or navigation." They assert, also, that the present degree of security 

 is due to no interference of government with mechanical arrangements 

 or prudential management, or to the enforcement of novel and sesere 

 principles of legislation, but to the inventive and discriminative pow- 

 ers, prudent foresight, and persevering spirit, of those engaged in that 

 important branch of public enterprise. The memorialists go on further 

 to urge, 



'• 'I'liat certain enactments of peculiar novelty and severity, found in tlie 

 act of Congi-ess of July, 183H,are calculated to hear harshly and oppressively 

 upon the owners of steam vessels, and thus to alfect injuriously, this important 

 branch of our navigation. Tliese enactments, instead of furuisliing encour- 

 agement for a just and generous rivalry, in bringing steam vessels and their 

 machinery to the highest possible state of security and perfection, have, nn- 

 fortunateiy, in the view of your menioriahsts, a direct tendency to deter men 

 of prudence, capacity and property, from further connexion with this husi- 

 ness ; who are unwilling to submit to implied reproacli and degradation, to 

 unwarranted hazards, and to the loss of rights aud privileges which are 

 guarantied to all other persons engaged in a lawful calling. Your memo- 

 rialists refer more especially, to the clause which deprives them of the uni- 

 versal legal protection common to every civilized country, liy unjustly con- 

 struing, in the event of iiiyscriotis disaster to life and property, the presump- 

 tion of innocence into /irhna facie evidence of guilt: and they respectfully 

 re<piest of your lionourahlc body, that a provision which is so much at variance 

 with their fundamental rights and privileges as American citizens, may he re- 

 pealed. 



" It is with painful regret that your memorialists have noticed an attempt to 

 procure a broader and more iniscliievo\is ajiplication of this unjust principle, 

 by means of proposed additions to this law; and they respectfully ask of 

 Congress to be protected from such ))roposed aggravations of the already se- 

 vere and relentless doctrines of the couimon law as it now governs the respon- 

 sibilities of common carriers; and which, if enacted, must tend to destroy 

 every just inducement for longer continuance in a business which is subjected 

 to siicli unprecedented liabilities to loss and ruin. These extraordinary hasards 

 and liabilities, it should lie noticed, will not pertain to om- competitors under 

 a foreign flag ; »nd our citizens may thus be virtually excluded from navi- 

 gating the ocean bv steam. Your memorialists would furl lier remark, that if 

 with the best knowledge possessed by this or any other country, this species 

 of navigation he deemed too hazanious for the public safety, the\ deem it 

 mure just and lionomablc to submit to its entire prohibition. 



"Your memorialists believe that few opinions are more erroneous than that 

 which ascribes to the provisions of the existing law a generally increased 

 safety for persons and property carried in steam boats. This may appear 

 from" the inanv accidents or disasters of a serious character which have t,al;en 

 lilace during the short period in which this haw has been in fore*. The num- 

 ber of these accidents on the western waters during tlie last yl-ar is stated to 

 liavc been fortv ; which may serve to convince Congress that the appropriate 

 remedies for these disasters are not fnrnishcd by this law ; and can be found 

 only in the increasing practical knowledge and skill of those persons who are 

 engaged in the construction and management of steam vessels. 



" Your memorialists do not seek to escape from any just responsibiUties in 

 conducting this important business. On the coiitran', they feel bound to 

 furnish every reasonable gnarantv for safety to life and property w hich liuman 

 foresight aiid prudence may be 'able to atford : aud it is for the purpose of 

 furnishing these guaranties 'in the most direct and practical manner, that they 

 further respectfully but earnestly request, that Congresi will e«U to the aid 



