184.8.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



37S 



The catastroplie of a government-purchase Mr. Gl_vn may anti- 

 cipate, and may have laid this trap to effect, for he has always 

 been a consistent supporter of such a coux'se ; but these are rather 

 dangerous times in which to try such strokes of policy. If a sop 

 must be given to the people, raiiWays will be sacrificed here, as in 

 France the provisional government proposed they should be, 

 under the amiable desire to gratify the people at the expense of 

 anybody. And English capitalists have already much suffered, 

 although the whole measure has not been carried out. 



The position of the Great AV^estern Railway under its shrewd 

 leader, Mr. Saunders, is the great element in the problem. He 

 has succeeded in getting the means of coercing the London and 

 North- Western after hard fighting ; and he is not likely now to 

 rate peace so highly as to give up for it the fruits of victory, 

 which offer themselves to his hands. What, too, is to be done 

 with the broad gauge ? After all the service it has done to the 

 public, is it to be set aside ? What compensation are the Great 

 Western to get for their varied claims ? These are all questions 

 to be solved, and to be solved satisfactorily in a pecuniary sense, 

 or it is very certain amalgamation will not go on. Mr. Saunders 

 has fought to get something, and he wUl have it. 



Mr. Glyn's motives in bringing about the amalgamation ai-e ap- 

 preciable. He effected that with the Grand Junction — he stayed 

 the dissension : and to carry out a further amalgamation, and to 

 appease a most dangerous competition are still greater measures. 

 Can he pay the price ? His shareholders have for years been plied 

 with the most rancorous insinuations by the narrow-gauge advo- 

 cates ; and will tliey in this day accede to those terms, without 

 which the Great Western will not give up their vantage-ground. 

 The South-AVestern directors and shareholders are glad to snap at 

 anything ; but the Old Grand Juncti(m shareholders, and the share- 

 holders in the Liverpool and Manchester Railways, (who have had 

 their dividends cut down), are notlikely to hear calmly any propo- 

 sition for giving high terms to a company which they have been 

 taught to believe is overcharged with liabilities, paying dividends 

 out of capita], and pursuing a ruinous system of management. 

 These falsehoods have been widely propagated, and have been 

 countenanced by those who ought to have knovvn better. Now 

 they will reap the fruits of falsehood. The narrow-gauge partisans, 

 editors, and pamphleteers, will find it hard to make the shareholders 

 believe a new tale, after what they have heard for years. 



It seems to have been left out of account by most parties,- that 

 the amalgamation will result in an increase of income and economy 

 of expenditure ; affording a surplus fund which under a liberal 

 system would go partly to extend public accommodation, hut 

 which in the present case will be divided between the three par- 

 ties to the amalgamation. This is the point for negotiation. The 

 Great Western may say, " Without us this amalgamation cannot 

 be carried out, and therefore it is fair we should have the larger 

 share ;" and as this is true, they are not obliged to accede to a 

 division in proportion to capital, and the greediness of the others 

 must give way. 



So far as we regard the public interests, we are most heartily 

 glad that this measure has been proposed ; for we are convinced 

 that the ultimate result must be for the public benefit, notwith- 

 standing what directors may believe. The latter may plume tliem- 

 selves that they have secured dear fares ; but we do not fear that 

 we shall have not only cheap fares, hut cheaper fares and greater 

 accommodation. Discussion must do good ; and discussion will 

 now take place on a wider and more liberal basis than it has here- 

 tofore done. 



What the end of the bill will be no one can say ; hut meanwhile 

 the shareholders will have something to think of, and something to 

 talk of at the meetings; and the directors will have time to look about 

 them. The Times nnd Punchhiive got a good cause; the public will 

 get excited ; and the bill may be postponed till another session, — or 

 may get into pai-liament, and the whole basis of railway legislation 

 be upset. 



Ships without A>p/s.— Captain Jean Napoleon Zerman, of the French 

 niivv, has recently taken out a patent in tliis country for the construction 

 of ships without keels. His ships are to be flAt-bollomec]; and through the 

 vessel, from stem to stern, there is to he an opening or trough ; the size 

 being about the width of one-third the greatest breadth of beam of the 

 vessel, and the height so much as just to be above the low-water line. The 

 patentee states his object to be, in adopting this mode of construction, en- 

 abling the vessel to draw less water, and take a greater hold of the water. 

 The vessels are so constructed as to go each way, and are to have a rudder at 

 each end. 



REVIEWS. 



Thmretkal and Practical Mechanics, designed principally for Prac- 

 tical Men. By James Hann, A.I.C.E., Mathematical Master of 

 King's College Scliool, London. Weale, 1848, Svo.; pp.324. 



We are scarcely in the position to review a book written by 

 Mr. Hann as impai'tial critics. A pre-disposition in favour of his 

 new work, arising from a strong impression of the merits of those 

 which preceded it, will be admitted by the reader to be, within 

 certain limits, a fair ground of criticism. Rut we have other 

 motives for a partial verdict, besides those patent to all who have 

 read Mr. Hann's former publications. The extraordinary zeal 

 which prompted him to the study of mechanical and mathematical 

 science — the sacrifices which he has offered to his favourite science 

 — these are considerations, derived from personal knowledge, which 

 cause admiration, mingled with somctldng like surprise. We are 

 too much accustomed to think that academic discipline is almost 

 indispensable for tlie attainment of that severe precision of thought 

 and language which is pre-eminently required in mathematical 

 studies. Here, however, those studies have been pursued in far 

 other scenes than the seclusion of a college, and with far other 

 means than the appliances of the professor's lecture, the tutor's 

 private instruction, the discussion with contemporary students, 

 and the powerful stimulus of a university examination. 



In Mr. Hann's work we occasionally meet with definitions and 

 expressions which seem to lack the precision of our accus- 

 tomed class-books. Our author in these cases, is not always, as it 

 appears to us, uninfluenced by impressions derived from the works 

 of inferior writers,— men who address themselves to practical en- 

 gineers, and have been too long deemed mathematicians because 

 they tise mathematical symbols. But if Mr. Hann and ourselves 

 be at issue respecting the value of the class of authors referred to, 

 this, at least, we concede — tliat if he sometimes borrow from such 

 books their unscientific phrases, he does not borrow their blunders 

 in the conception and application of principles. In turning over 

 English books on engineering and analogous subjects, we usually 

 adopt a rule, derived from vexatious experience, never to trust to 

 the result of a single investigation till after having worked it over 

 a^ain for ourselves. In looking over the pages of tliis book we 

 do nothing of the kind ; we do not expect to find at every turn an 

 error of principle. On the contrary, we have not yet found but 

 one result which we are disposed to dispute : this occurs at page 

 205. 



" Suppose, by measurement, it be found that a man-of-war, with its ord- 

 nance, rigging, and appointments, sink so deep as to displace 1,300 tons of 

 sea-water, — wlmt is the whole weight of the ship, supposing a cubic inch of 

 sea-water to weigh -5949 of an ounce avoirdupois? 



" The weight of the water displaced is equal to the weight of the ship. 

 216 gallons = 1 ton. 1300 x 210 = 280,800 gallons; and if we tak^ 

 277-2738 cubic inches to the gallon, then 280,800 x 277-2738 = 

 778,584 ; 83-04 cubic inches ; and this multiplied by -5949 gives 

 463,180, 11-5307 ounces = 1292-35 tons, the weight of the ship." 



Surely there is an error in this passage. If the displacement of 

 the ship be 1,300 tons, it will weigh 1,300 tons — not an ounce, not 

 tlie millionth-part of a grain, more or less. Here, however, with- 

 out any apparent reason, the displacement is reduced from tons 

 to cubic inches, and then brought back again to tons ; and the 

 several multiplications with decimals account for the eight tons 

 lost in tliis unnecessary process. The error is, however, evidently 

 accidental. 



About one-third of Mr. Hann's work is devoted to the theory of 

 statics ; and considering the class of readers for whom his work is 

 intended, he has acted judiciously in avoiding, as far as possible, 

 complicated mathematical operations. AV'e wish that it could have 

 been found practicable to substitute arithmetical methods for the 

 somewhat difficult analysis which occurs in the subsequent pages. 

 The chapter upon Revetements (p. 209-223), for example, consists 

 almost entirely of mathematical symbols, and is not, therefore, 

 likely to have much practical utility. Besides, we have strong 

 doubts whether any system of theoretical computation will express 

 even ap])roximately the pressure of earth upon sustaining walls. 

 Coulomb's idea of the wedge of maximum pressure is, in a scien- 

 tific view, extremely beautiful; but in practice many things con- 

 cur to vitiate all deductions from the theory. In railway cuttings, 

 stratified formations which dip to the horizon will be liable to 

 slide forward where the inclination is towards the face of the cut- 

 ting ; and when the inclination is in the reverse direction, the strata 

 may sustain each other by their mutual action. In this way it will 

 happen that, in a railway cutting through inclined strata, the 



