o6 



Till'] CIVIL ENGINEER AND AllClllTECT'S JOURNAL. 



[Feb. 



LEVELLING. 



Sir— At page i'M of your juunial, I have just read \V. 13cnlcy's remarks 

 on tlie sulijcct of attaining the correct bisection of a levcllini; stalt'; and 

 althongli I cannot asrec with his plan of " tlie liolder moving it slowly and 

 firmly to and fro, in the jilane of the observer, the base of the stall' acting in 

 its seat as a hinge," because I believe, by such means that the base of the 

 start' would in some degree work itself into the ground (except an universal 

 joint was attschcd to the foot), which, if at a back station, would occasion a 

 certain error ; probably of much greater amount than would be occasioned by 

 a reading from the statt' when in an oblique position. The principle of adopt- 

 ing the Icaxf reading on the staff is of course correct, and is really well worth 

 the attention of every person engaged in levelling operations. But I have 

 always found, that with the most carefid holder, and on a calm day, the 

 inevitable unsteadiness of hand was suflieient to enable one to practise this 

 plan with certainty. In windy wcatlier, the vibration of the staff always 

 ensures the same result, constantly passing and repassing the perpendicular. 

 In conclusion. Sir, allow me to state, that in my opinion, the shiiple plan 

 detailed in W. Rowley's letter is well worthy of your readers' attention ; and 

 there is the reproach conveyed in the postscript to W. Stevenson's letter, at 

 page 20 of your last uumber, unmerited. 



1 remain, Sir, 



Chariotle-strcet, lUoomsburi/, Your obedient servant, 



Jan. 13, 1812. Peter Brui'f. 



LONG AND SHOUT STEAM VOYAGES. 



Sin — A correspondent Z in your last number appears to lean to the opi- 

 nion of Dr. Gardner respecting the profit to be derived from long and short 

 voyages l)y steam. 1 think, however, he is not borne out by the examples 

 adduced. With respect to the hst of transatlantic killed and wounded, men- 

 tioned by him, it is necessary to say a few words in explanation. 



" Sirins withdrawn." — The Sirius was a small vessel, and was never in- 

 tended to be kejit permanently on the transatlantic station. She was char- 

 tered for a voyage or two by the lomjiany owning the British tjuecn and 

 President, while their shijis were building, and though sailing from an Irisli 

 port, was, I believe, the most unprofitable of all, and the soonest withdrawn. 



" The lloyal M'iUiam " — was also a small vessel, chartered by another 

 company until their own vessels were ready. 



" Great Liveipool transferred." The Liverpool was certainly nnsuccessful. 

 This arose jiartly from the circumstance of her retiu'n on the first voyage 

 after being out some days, which created an unfavourable impressiou against 

 her, anil being an indifferent sea-boat, she never attracted many jiassengers. 

 She has since been altered by giving her six feet more beam, and is now, I 

 believe, a very superior vessel. 



" United States or Oriental transferred." — She was intended for the sta- 

 tion, hut never made a voyage. 



" British Queen sold." The British Queen made an average profit on nine 

 voyages of .i'1256 per voyage ; and before the opposition of the Cunard Hne, 

 which is assisted by a Government contract, considerably more. 



" The President lost."— The President made an average profit of .C1350 

 per voyage Tvhile she ran. These two ships belonged to the same company, 

 and would have paid a handsome divi<lcnd on their cost, had it not been for 

 the Cunard* opposition, and the unfortunate loss of the President, which 

 was insured for a fourth )iart of her value only. She therefore took to the 

 bottom with her the .fCO,000 of the company's capital mentioned by Z, and 

 swamperl her owners. 



" Great Western and Great Iron Steamer for sale." — I am unable to say 

 whether these are for sale or no. The Company have some disputes whether 

 they shall budd their own ships or not ; and as the courts have decided 

 against them, their building-yard is advertised for sale. The Great Western 

 has regularly divided nine per cent, on her cost, besides laying by a consider- 

 able reserve fund ; so she can scarce be quoted as a proof of non-success 

 with long voyages. Your correspondent says that a "recent meeting of the 

 Peninsular and Oriental Company enables us to state, that oriental steam 



voyaging has been highly successful ; ami this result has been attained with 

 the same vessels, and by the saine managcnicnt, that were incapable of 

 realizing anything but loss on the New York line." That the vessels are 

 under the same management, is entirely a mistake ; tliat they pay a good 

 dividend (seven per cent), is quite true. But how .' The Company's capital 

 is .t'300,000, and they receive from Government £00,000 for conveying the 

 mails to Lisbon, Gibraltar, and Alexandria. It is evident that without this 

 Government assistance, the Company's vessels, with their short voyages, 

 woLild not be dividing .£21,000 a year among the proprietors, but would, as 

 Z says, be still realizing a most considerable loss. I think therefore, from 

 what I have said respecting the Great Western and these latter vessels, it 

 will appear, that the length of the voyage is of far less consequence than the 

 probability of a full ship to make it with. 



I have the honour to be. Sir, 



Your obedient servant, 



jVn Amateur. 



• The Cunard opposition is stated to have reduced the passage money 

 20 per cent, and to have reduced tlie number of passengers from an average 

 of 240 to an average of lO.'j per voyage. 



MODEL MAPPING. 



Sir — I have perused with considerable iuterest your report of Mr. 

 Sopwith's paper on the construction and use of Geological Models, for 

 which he was awarded a Telford medal by the Institution of Civil 

 Engineers, — and I trust you will allow inc to make a few remarks on 

 the analogy his jiroposition bears to the one I liave advanced in my 

 little work of Model Mapping, in which I suggest, that in all cases 

 where the owners of estates are desirous of informing themselves, of 

 the material and undersoils, as well as the surface and contents of 

 their lands, Model Maps should be extended in their usefulness, so far 

 as to portray geological formation. The mode I propose is to sink 

 shafts in the model correspondingly with the borings taken on the 

 ground, and into these shafts to insert rods of the same length as the 

 depth iif the borings, coloured geologically, to vertical scale ; each diffe- 

 rence of colour agreeing precisely with the strata of subsoils, as reported 

 by the borers. The rods wouUi be made to fit neatly in the shafts, 

 though easy of removal, and would assimilate in use to the (jrocer's 

 CktSftasIci; which, when \\ithdrawn from the cheese, identifies its 

 rpialities. Of course, I would not be understood to feel otherwise 

 than that Mr. JS.'s method is superior for mining ]iurposes, but as the 

 one I suggest does not render a division of the model necessary, but 

 conveys to the observer the pure information derived from the borings, 

 1 am induced to believe that landowners interested in geology, and not 

 initiated in civil engineering, would prefer it, as the simplest and 

 least troublesome method, were their attention turned to the matter. 

 I am, Sir, 



Your obedient servant, 



J. Bailey DiiNXuN. 



0, Gray's Inn, Deamher U, 1S41. 



STUDY OF CIVIL ENGINEERING AND ARCHITECTURE. 



Sir — Believing you are ever ready to give publicity to any sugges- 

 tions which may have utility for their object, I beg to ofter the follow- 

 ing considerations, which, should you deem ot sullicient importance to 

 claim a place in your Journal, you will kindly insert. A very few 

 years since there was no place in existence where the study of Civil 

 Engineering or Architecture could be prosecuted as a separate science. 

 The student designed for either of tliese professions was compelled to 

 wander through an intricate maze, w ithout guide or compass to direct 

 him, and often, as is too v\'ell seen at the present time, entered upon 

 his duties without having even laid the foundation of a scientific 

 education. There have been some attempts of late to till up this 

 chasm in the educational establishments of tliis country, by instituting 

 departments in several of the Colleges and Universities, where the 

 attention of students is exclusively devoted to subjects in relation to 

 these branches of study; as also by the foundation of the College for 

 Civil Engineers. Now these have, I am aware, in part supplied this 

 desideratum, but in part only. Who is it that derives any benefit 

 from these existing Institutions? are they the few or the many ? most 

 undoubtedly those only who have money in plenty, and the greatest 

 portion of their time to devote exclusively to the acquirement of 

 knowledge. But there are still a considerable number who not having 

 such advantages, enter prematurely into offices, and therefore engaged 



