44 



THE CIVIL ENGINEER AND AUCHITECTS JOURNAL. 



[FEBRrABT, 



quently from precedent, — although precedent, such as it is — and it 

 is certainly more cockney than classical — may be found, namely 

 Temple Bar, whose gateway is only 19 feet high, although 21 feet 

 in width. 



Supposing the large arch to be made iO feet high in the clear, 

 about 20 feet more will be required for the height of the whole 

 structure — that is, according to most examples of the kind ; so 

 that the whole would form a "mass about 80 feet in length by 60 feet 

 in height. Now, we do not object to a work of such magnitude ; 

 yet how is it to be accomplished for the inadequate sum of 2,000/.^ 

 The arch in the Green Park, which is only 62 feet in length by 

 60 feet in height, is stated to have cost somewhere about 30,000/, 

 It must be admitted that it is so deep a mass, that two of the same 

 size in other respects, but much shallower, might have been erected 

 for the money : let us therefore take the cost at 10,000/, exclusive 

 of foundations. Yet, allowing for the same exclusion, only one- 

 fifth of that sum is to be expended upon an Ornamental Building, 

 of very considerable size. The epithet "ornamental" implies, we 

 presume, that a more than ordinary degree of decoration is looked 

 for, — perhaps sculptural embellishment as well as architectural. — 

 The problem seems to be so difficult a one, that we hope even its 

 difficulty will be productive of good, by compelling the competitors 

 to depart from the regular track, — to fling precedent overboard, 

 and strike out some new ideas. 



REMARKS ON RAILWAY AXLES. 



Sir — A few years ago, there existed a great difference of opinion 

 concerning the best form for railway axles, which often occasioned 

 much unprofitable discussion among some of our mechanical en- 

 gineers. The question has lately been silent, and experience or 

 imitation appears to have decided the form now most generally 

 approved. There is, however, a wide difi'ereuce in the dimensions 

 and quantity of material in the axles used for similar purposes by 

 different companies. This circumstance, together with the great 

 importance of having a safe axle, shows the necessity of an estab- 

 lished system of proportions for future guidance, as every one con- 

 nected with railways is aware of the important saving that would 

 be effected by dispensing with only a few pounds of unnecessary 

 material in each axle of a railway company's stock. 



t^ 



1 



t^ 



Ar 





A B ^ 



The foiir annexed figures are intended to represent the different 

 forms that have been used. No. I, which is thickest in the middle 

 and tapered towards each wheel, appears to be altogether thrown 

 aside ; No. 2, which is parallel between the journals, is still fre- 

 quently used ; No. 3, which is parallel from A to B, and No. -t, 

 which is diminished from each wheel to the centre, appear to be 

 the two forms now most in use, — the latter, however, being, it is 

 believed, the most correct. 



The writer is in favour of No. 4, although he has not had the 

 pleasure of seeing any satisfactory proof of its being the most 

 correct. In the following experiment he was, however, convinced 

 that these axles require to be smaller in the centre than at the 

 wheel bosses, but in what exact projiortion he has not been able to 

 decide. In the experiment alluded to, a parallel bar of cast-iron, 

 of longitudinal dimensions similar to those of an ordinary railway 

 axle, was placed upon two supports, C C, as substitutes for the 



L 



JliL 



E F 



a. 



-^ 



ciT 



wheel bosses, as here shown, and then submitted to forces acting 

 equally upon each end at equal distances from the supports, which 



points, D D, were supposed to be the centres of the journals: the 

 force being gradually increased, the bar broke simultaneously 

 through E E. The experiment was repeated; but in the second 

 trial the bar broke only in one point, F, — being a little nearer to 

 the middle. This was considered sufficient proof tliat a portion of 

 the metal might be removed from the middle of the bar without 

 diminishing its lateral strength; and that by adding this metal 

 about the points E E, the lateral strength would be increased. 



The result of this experiment was applied to a number of rail- 

 way axles for 4. ft. 85 in. gauge, which were to have been made of 

 4 in. parallel bar, but were altered to the form No. 4, being 4| in. 



diameter in the wheel bosses, and 3^ in. diameter in the middle, 



which was calculated to require no more material than if they had 

 been made 4 in. throughout, as originally intended. It still re- 

 mains a question whether this difference in the diameter of the 

 body of the axle was the most correct, as it was decided by mere 

 supposition subsequently to the above experiment. 



Besides the most economical form for the body of an axle, it is 

 of importance to have journals equally well-projiortioued. The 

 journals were formerly very short compared with some of modern 

 make : four inches was not an unusual length, but they have kept 

 gradually increasing, and six inches is now become very general ; — 

 there are indeed instances which far exceed this dimension. The 

 gradual changes which have been going on in this, as well as in 

 other parts of the axle, also prove the want of more correct data. 

 The object of this paper is not to lay before your readers any new 

 idea relative to the form and proportions of railway axles, but 

 merely to call the attention of practical men to the subject, whose 

 long experience and observation could not fail to supply much that 

 is required. 



The narrow limits of the writer's own observation in railway 

 matters, would not warrant him in offering more than a mere sug- 

 gestion, and as such he begs to submit the following formula, which 

 it is hoped will not be found totally void of utility. 



a/ 



Wherein a ^ A B (fig. 4) in inches , 6 = B C in inches ; c = the 

 number of wheels to the wagon ; D ^ diameter of the journals in 

 inches ; and w =: the greatest load to be borne by the wagon in 

 cwts., including the weight of the wagon. 



Your obedient servant, 

 Manchester, Jan. 6, 1849. J. N. 



REVIE^VS. 



THE PHILOSOPHY OF NATI'RE A.Vf) ART. 



An Historical Inquiry into the True Principles nf Beauty in Art, 

 more especially with reference to Architecture. By Jajiks Fkugusson, 

 Esq., Architect ; author of " An Essay on the Ancient Tojiography 

 of Jerusalem," " Picturesque Illustrations of Ancient Architec- 

 ture in Hindostan," &c. Part the First. London : Longmans, 

 1843. 



fsECONP NOTICE."] 



We continue Mr. Fergusson's review of the state of science, and 

 the field which is open for its further cultivation, because we think 

 it will do good in science as in art to show how much remains to 

 be done, and the encouragement there is for a zealous student. It 

 was the belief there were worlds to conquer that stimulated the 

 ambition of Alexander : it was because he knew of none open to 

 his ambition that his energies palled. The belief that we are too 

 near the goal has dispirited many a learner, and has done much to 

 retard the progress of knowledge ; whereas all that we have done 

 is only a reason and a means by which to do more. 



In considering the state of Botany, Mr. Fergusson dwells upon 

 the importance of investigating the phenomena of life; but still 

 he does not show their full influence. Botany is too much looked 

 upon as a study of dead substances ; but without we contemplate 

 from the beginning the operations of life, we can have no good 

 system of physiology. Life introduces action, — action, counter- 

 action ; and the first moment of life is the first indication of decay. 

 There is a sequence throughout dependent on a first cause, and 

 this must be carefully observed. Life constitutes, the author 



