388 



TTTE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[OCTOBKR, 



for Mich till cxiicrinicnt, aiul a<'coiclingly a train of twelve eoaclici was ]ii'e- 

 pai'ed, each coach being loaiioil to tlic gross weight of live tons. An engine, 

 tallcil tlip Ilecta, was iiroviileil, weigliing twelve tons, witli her tci;(ler 

 weighing ten tons, making a gross loatl of eiglity-two tons. It was deter- 

 niiiieil to rnn this train from Liverpool to Uirmiiigliam and liael;, oliserving 

 wilh tlie nt most precision, tlie nnnnent of passing each <|n,'rlcr-niiie post, 

 ami ohiaining tliereliy the actual speed with which evci'y gradient, from one 

 end to tlie other of the line, was ascended and descended, and the velocity 

 on the hovels. By taking a mean of the speed in ascending and descending 

 tlie gradients, it would he necessary, if the doctrine held liy him had any 

 trntli in it, that tliis mean shonhl he exactly, or very nearly, equal to the 

 .speed on a level. The jourm^y was accordingly pcrl'ormed, and the results 

 of it will he pnljlished in detail in Dr. Gardner's second rcjiorl. l!nt, in the 

 nieanwliile, the speed, in ascending and descending the several gradients ami 

 the mean between them, is exhibited in Table X. 



Taldc X. 



(iradient. 



Speed. 

 Ascending. Descending. 



One in 

 177 



2cri 



330 

 •100 

 532 

 :,90 

 650 



nnles per h. 

 22-25 

 24-87 

 25-20 

 26-87 

 27-35 

 27-27 

 29-03 



miles per 

 -11-32 

 39-13 

 37-07 

 36-75 

 34 -.30 

 33-16 

 32-58 



h. 



Level . 



Mean. 



31-78 

 32-110 

 31-10 

 31-81 

 30-S2 

 30-21 

 30-80 



30-93 



lie said, that on this table it is scarcely needful to make a single observa- 

 tion. It is quite evident, that the gradients do possess the compensating 

 power which he ascribed to them. The discrepancy existing among the 

 mean values of the speed, is notliing more tlian what may he ascribed to 

 casual variations in the moving power. This experiment also was made 

 nnder very favom-able eircumstanees, tlie day being quite calm. M'ithont 

 going into the details of the principle on wliich these remarliable results 

 depend, it may be stated generally, tliat since the chief part of the re- 

 sistance of a railway train depends on the atmosphere, and is proportional 

 to the square of the velocity, a very small diminution in the velocity itself 

 produces a considerable dirainntion in its square. A train, in ascending a 

 gradient, may therefore relieve itself from as much- atmospheric resistance 

 as is equal to the gravitation of the ]dane by slackening of its sjieed. If its 

 speed lie slackened so as to render the resistance equal to tliat which it 

 would have upon a level, then the engine would have to worlc witii a less 

 ev3{)orating power than on a level, inasmuch as the motion would be slower. 

 In jiractice, therefore, it can never he needfid to slacken the speed so much 

 as to e(|nali/.e the resistance with that upon the level. Supposing the 

 evaporating power to remain the same, the speed need only lie slackened, so 

 that with the same evaporation an increased resistance can be overcome at a 

 speed less than the level, bnt not so much less as would render the re- 

 sistance equal to the level. This, in fact, is what takes place in practice, as 

 is apparent from the results above given. 



Dr. Lardner eorichided by stating in detail a number of conclusions which 

 lie considered to be warranted by the experiments ; l)\it he reserved to him- 

 self the power, when the experiments should be all reduced, of modifj-ing 

 these conclusions, if it should appear necessary to do so. lie stated, that 

 many of the experiments had been only recently made, and had conse- 

 quently not been s\djmitted to mathematical analysis. Meanwhile he had 

 taken care to l.iy nothing before the Section, except wlial had been fully 

 borne out by the experiments themselves, lie regarded the following con- 

 clusion as established hy his experiments. 



1. That the resistance to a railway train, other things being the same, de- 

 pends on the speed. 



2. That at tlie same speed, the resistance will be in the ratio of the load, 

 if the c-irriagcs remain unaltered. 



3. That if the number of carriages be increased, the resistance is in- 

 creased, but not in so great a ratio as the load. 



4. Tliat, tlieiefore, the resistance does not. as has been hitlierto supposed, 

 hear an invariable ratio to the load, and otii//tt no/ to be cvjirexscil at so mvcti 

 )ier ton. 



5. That the amount of the resistance of ordinary loails carried on rail- 

 ways at the ordinary sjieeds, more especially of ])assenger trains, is very 

 much greater than engineers have hitherto supposed. 



6. That a considerable, but not exactly ascertained iiroportion of this re- 

 sistance is due to the air. 



7. That the shape of the front or bind part of tiie train has no observa- 

 ble etfect on (he resistance. 



8. That the spaces between the carriages of the train liave no observable 

 etfect on the resistance. 



9. That the train, with the same width of front, suffers increased re- 

 sistance witli the increased hulk or volume of the coaclies. 



10. That mathematical formnhc, deduced i'l-om the sujiposition that the 

 resistance of railway trains consists of two ]mrts, one proportioned to the 

 load, but independent of the s)ieed, and the other |iiO)iortional to (he square 

 of the speed, have been ap]jlied to a limited nnnilicr of experiinenis, and 

 have given results in very near accordance, Init that the experiment must be 

 further multiplied and varied before safe, exact, and general conclusions can 

 be drawn. 



11. Tliat the amount of resistance being so much greater than has been 

 hitherto supposed, and the resistance produceil by curves of a mile 

 radius lieing inappreciable, railways laid down with gradients of from six- 

 teen to twenty feet a mile have practically but little disadvantage compared 

 with a dead level ; and that curves may be safely made with radii less than 

 a mile ; bnt that further exiierinicnts must be made to determine a safe 

 minor limit for the radii of such curves, this prineijde being understood to 

 be limited in its application to railways intended chiefly for raind traflic. 



In the course of his address, Dr. I.ardner took occasion to acknowledge 

 the very valuable assistance which he had received from Mr. Edward 

 Woods, tli£ engineer of the Liverpool and Manchester Railway, who assisted 

 Dr. Lardner in almost all the experiments, and coudueled some of them 

 himself ill Dr. Larducr's absence. To the skill and intelligence of that 

 gentleman, as well as to his general m.ithematical acquirements, be felt 

 himself much indebted. Mr. II. Earle was aiso associated in these experi- 

 ments, and took part in the direction of many of them. 



FINE ARTS IN ITALY. 



We give insertion to the following well authenticated anecdotes to show 

 that many of our wealthy coimtrynien are moat cgregiously imposed upon in 

 their quest of old pictures and ancient statues ; this mania has become so 

 general that many artists of talent are compelled to fabricate old pictures re- 

 puted to have been painted by the ancient masters ; statues, busts, and frag- 

 ments of sculpture arc chiselled out of Greek or Parian marble, and to favour 

 tlic ileceptiou they are defaced and stained hy iron rust and tobaeco-juiee, to 

 give the fragments the appearance of having been decomposed and stained 

 by the hand of time. Coins anil engraved gems are also commonly made and 

 sold as antique. It is but justice to declare that we have seen works in 

 sculpture in imitation of ancient art so well executed, and their style and 

 character in such strict unison with the purity of Greek art, that they have 

 baflle<l the most experienced eye to discover the fraud. The celebrated 

 Giroma^tti of Rome, by command of the late Pius 8th, made a copy of a gem 

 engraved by Discorides, both the original and copy of which were deposited 

 in the museum. One however was stolen and sold by the purloiner to a 

 nobleman for a large sum of money, but most fortunately the stolen cameo 



]n-oved on examinatiou not to be the original. A Mr. an EugUslinian 



of some considerable attainments and taste for the fine arts, was commis- 

 sioned hy the English Government to visit Rome for the jinrpose of pur- 

 chasing works of art for the British Museum ; on his arrival in this city, he 

 fuund his way to the sanctum sanctorum of Vescovalle, in Piazza di Spagna, 

 a dealer in antiquities, when that man of art exiiatiated with all the subtile 

 eloquence of an Italian, on the merits of his wares. Our countryman felt 

 flattered at the compliments so unsparingly paid to Ids taste and discernment 

 in having selected some of the most soul-breathing creations of the chisel. 



Mr. elated with his good fortune, called on our distinguished fellow- 



couiitiynien Gibson, the eminent sculptor, to invite him to a high intellectual 

 treat, and on (he road to the shop Mr. M. spoke of Phidias and Praxitiles, 

 and dwelt with the eloquence of a Pliilostratus on the beauties of the works 

 which he bad selected, giving quotations from Pliny, M'inkleman, and Viseonti, 

 in proof of their authenticity. Our artist felt humbled in his own estimation 

 after such Demostheniau eloquence, and tilled with veneration as a lover of 

 Greek art, they entered the studio where our man of letters pointed with 

 conscious pride to the objects he had selected ; our sculptor was tbnnder- 

 struck, not .at the beauties of the works, hut at the statues, as they were 

 indeed nondescripts, monstrosities, composed of odd fragments, the works of 

 sculptors of the time of Coustantine, consequently of the worst era of Roman 

 art. 



WILLIAM WILKINS, A.M., F.R.S., &c. 



It is our painful duty to annonnee the demise of Mr. Wilkins, Professor 

 of Architecture to the Royal Academy, who died at his residence at Cam- 

 bridge, on Saturday, August 31 last, in the 61st year of his age : his remains 

 \\('ic iiilened in the chaiiel of the College of Corjins Christi. 



.Mr. Wilkins entered the Cambridge University as a schokar of Cains and 

 Gonvillc College, in 1796, .and graduated in 1800, as sixth wrangler of his 

 year. In 1801 he succeeded to the University Travelling Bachelorship, and 

 passed four years in Greece and Italy in the prosecution of his studies, amongst 

 the rem.ains of ancient art, prejiaratory to commencing his profession of 

 architect, and during which time he was elected a Fellow of his College. 



.\moiig .Mr. Wilkins' earlier works are Donningtou Castle and Osbertou, 

 (of both of which, elevations, &e., may be found in "The New Vitruvius 

 Eritannieus,,) but neillier liave much architectural merit. At Cambridge he 



