810 



THE CIVIL ENGINEER AND ARCHITECrS JOURNAL. 



[Oct. 



which is now ten per cent., to eight per cent. ; then to seven, then to six, 

 then to live, then the commutalion for government stock. Mr. Gljn ami 

 his party may think that ten per cent., under the guarantee of the govern- 

 ment, is the best thing they can have ; but they can never liave it, for a 

 government guarantee is \\'ortli nothing. It has been siiown already ; Mr. 

 Hudson has denounced the breach of faitli with the companies; but this is 

 in time of peace and a mere ambitious movement on the partof Mr. .Strult; 

 but what will the government guarantee be worth, when the ministry of 

 the day oiler, for an election bait, a reduction of railway profits and 

 charges? — which will be an eligible measure, as it will nol be at their own 

 expense. An additional 1 per cent, on the income lax may very well be 

 met by a diminished 2 per cent, on railway dividends, — and chancellors of 

 the exchequer are not scrupulous on such points. 



The real enemy of railway and engineering interests, and of the public 

 interests in such matters, is the government, and they have shown it. 

 They have ambitious ends to serve, and they do not care how they gain 

 them. They have traded upon the unpopularity of railways, they have 

 created a great patronage and a great influence, but what single good 

 have they done for the public ? " They have diminished railway acci- 

 dents." They have done nothing of the kind. The development of the 

 railway system has diminished accidents ; but government inspection has 

 been found to be no safeguard and no remedy : bridges fall down after 

 they are inspected, lines are obliged to be closed, and inspectors make 

 reports afler accidents to tell tlie public what the newspapers tell them 

 much belter. — "They have lowered fares and tolls, and obtained better 

 accommodation for third-class passengers." They have done no such 

 thing, for fares are lowered in consequence of the growing conviction that 

 the lower the fares, the larger the traffic and the greater the profits; while, 

 by interfering with third-class accommodation, the Board of Trade has 

 created a prejudice and indisposed the companies from extending accom- 

 modation. Mhile the Board of Trade have done no good to the public, 

 they have unsettled railway property ; and the first thing for ite safeguard 

 is to do away with Board-of-Trade inspection altogether. 



THE BLADE PROTRACTOR. 



fWith an Engraving, Plate XVI.) 

 Registered by Mr. James Basire, .Jun., o/ Red Lion Square. 



We have much pleasure in introducing to our readers a new and useful 

 instrument, invented by Mr. Basire, for the purpose of facililaling the 

 plotting of trigonometrical surveys. It is a very important improvement 

 on the protractor, and consists in the addition of a bl.ule fixed to the arm 

 of the instrument, as shown at fig. 1 in the Engraving, and by the aid of 

 which the lines are at once laid olf, without the trouble of first pricking off 

 the point, as shown in fig. 2, which in the plotting of some surveys oc- 

 cupies considerable time ; besides which, the work is done with much 

 greater accuracy, as it is only necessary to fix the instrument on a meri- 

 dian and draw the angles at once. 



For military and mining surveying, or other work set out by angles, this 

 instrument will be invaluable, and to architects and artists of great service 

 for copying, reducing, or enlarging drawings. In the Engraving an ex- 

 ample is given in fig. 3, showing how the instrument is applicable for 

 marine surveys : the blade protractor is first placed on the station A, and 

 all the angles at once drawn off; it is then shifted to the next station B, 

 and the angles laid off bisecting A and C ; and so on. 



The instruments are got up in German silver, and are furnished with 

 four blades containing various scales, and placed in a neat and compact 

 case, and are to be had of the inventor. 



Tunnel across the St. Lawrence. — A project is spoken of in Canada, for 

 connecting the railroad running to the Atlantic, by tunnelling the St. Law- 

 rence, opposite the island of Montreal. I'lie tunnel at its narrowest part, 

 near St. Helen's Island, will be about one-third of a mile from shore to 

 shore, and about one-third the length of the principal tunnels in England. 

 The depth of the water in the river is 43 feet. 



Dec Bridge Girders. — One of the girders of this bridge has been tested, 

 to ascertain llie breaking weight. The experinient was made on the 8lh 

 ult., by the ofiicers of the Chester and Holyhead railway, by gradually 

 placing railway bars over the centre division of the girder, until it reached 

 38 tuns Gcwt. 2 qrs. 181b., which broke it, the fracture commencing at the 

 bottom flange. 



SLUICE GATES AND RAILWAY LIFT BRIDGE. 



Sir — At page 241 of No. 119 of your excellent Journal, is the descrip- 

 tion (taken from the Franklin Journal) of a new sluice gate, invented by 

 F. C. Lowthorp, civil engineer, of Pennsylvania. Allow us to claim the 

 priority of this invention for one of our countrymen, long since deceased, 

 and thus discharge a debt due to the memory of one who directed the first 

 steps of our professional career and who was to us both a friend and a 

 master. 



It is now about 30 years since T. Blankln, Inspecteur general du 

 V aterstaat in Holland, well known by his grand Canal of the Helder at 

 Amsterdam, erecteil in this country the first sluices with what are termed 

 fan-gates (u eientail, waaijcrdeuren). These gates are precisely similar to 

 those described in your Journal, except that their application and the flow 

 of water are arranged in a simpler manner than by the American engineer. 

 The first experiments having perfectly succeeded, the king Louis Napoleon 

 decreed that these sluices should bear the name of the inventor, and gave 

 them the title — Blaukensluizen. 



A large number of the sluices of this country, of which the openings 

 vary from 4 to li; metres (13 to 39 feet), have been constructed on this 

 principle, and their use has become general among us. M. Wiebeking has 

 given a description of them in his large treatise on hydraulic works. 



Permit us, at the same time, to claim the priority of the application of 

 the Railway Lift Bridge, of which you give a description at page 241 of 

 the same number. A moveable bridge, on this principle, was erected last 

 year on the railway from the Hague to Rotterdam. 



We trust. Sir, that you will have the goodness to insert this brief expla- 

 nation, and beg you to receive the assurance of our perfect esteem. 

 (Signed) F. W. Conrad, 



L. .1. A. Vander KiiN, 



Hague, Sept. 13, 1847. (Dutch engineers.) 



REVIE'WrS. 



Observations on Lime, Calcareous Cements, Mor/ars, ifc, ByMajor- 

 General Sir C. W. Paslet, K.C.B. Second Edition, Fart L London: 

 John Waile, 1847. Pp. 209. 



Both the engineer and architect are under great obligations to 

 General Pasley (or the very elucid manner he has set forth in this 

 tre.itise the result of many years' laborious researches and experiments 

 on limes, mortals, and cements. When the first edition of this work 

 appeared in 1839, we then perused it with great pleasure, and strongly 

 recommended it to the profession ; and as a proof of the cor- 

 rectness of our opinion, tlie work was very soon out of print, and has 

 been since much sought after, which induced the author to publish 

 a second edition. He miy well be gratified to find th;it his laborious 

 researches have induced several manufacturers nnder clift'erent appella- 

 tions to m.inuraclure the artificial cement recommended by hini. The 

 General observes in his introduction, — 



" When he first published his researches on the subject, all the previous 

 attempts to make a good artificial cement in tiiis coumry had so far failed, 

 that only one sort, that prepared by Mr. FrosI, had found ils way into the 

 market, which was of mferior quality, owing chif fly lo certain defects in 

 the mode of preparing the ingredients, poioied out in the First Edition of 

 this work. Al present there are three manufactories of artificial cement 

 in England, which have all been used more or less extensively in works of 

 importance, and have given satisfaction; viz., first, that of Messrs. .John 

 B. While and Sons, in Ihe parish of Swanscomb, Kent, the present proprie- 

 tors of Mr. Frost's works, who, afler gradually relinquishing the objection- 

 able parls of bis process, liave succeeded in making a good artificial ce- 

 nieiil, wliich they call their Portland cement, by a mixture of chalk 

 found on Iheir own premises widi the blue clay of the Medway; secondly, 

 that of Messrs. Evans and Nicholson, of Manchester, who make an artifi- 

 cial cement, which has been called the patent lithic cement, with the 

 very same ingredients, and in the same pioporlions nearly, ihal were u-ed 

 in the Author's experiments, but the most important of which is obtained 

 in a roniid-about manner from the residual matters or wasle of certain 

 chemii al works, instead of working with natural substances ; thirdly, that 

 of Mr. Rithard Greaves, of 8lrallord-upou-Avou, who makes a powerful 

 water cement, which he calls BLUE lias cement, by mixing a proporliou 

 of indurated clay or shale with the excellenl blue lias lime of Ihal neigh- 

 bouriiood, both of which are found in the same quarries ; the fiiriui-r being 

 previously broken and ground, and the lalier burned and slakeil, which is 

 absolutely necessary in making an artificial cement from any of the hard 

 lime stones. 



