1844.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



403 



and he thought no farmer would fay lie lost less than that by rats and other 

 vermin, which would be obviated by the use of this machine. 



On Heating by Steam, 



Mr. W. West read an account of some experiments on heating by steam. 

 Having reason to believe that water heated by steam did not reach the boil- 

 ing temperature, even when the steam escaped in abundance, and the water 

 was violently agitated, Mr. West made a number of experiments to ascertain 

 the fact. In one nf these experiments, the water only reached 20ri", in 

 another 190°, and in another 207 ". Steam from water in the same appara- 

 tus which was used throughout was then passed through water ; but with an 

 addition of the receiving vessel, of a second, or false bottom, pierced with 

 numerous small holes. It was then easy to maintain a temperature of 21 2^ 

 with the same means of producing steam, and apparently a similar, or rather 

 a smaller quantity, 



O.v THE Resistance or Railway Trains. — By Mr. Scott Russell. 



The paper detailed a number of experiments on the Sheffield and Man- 

 chester Railway. For tlie purpose of these experiments it is necessary that 

 the railway should present long and very steep gradients, and no where else, 

 were these advantages presented in greater al)UTulancc tlian on the Sheffield 

 and Manchester railway. The experiments were as follow : — 



1. Trains of carriages, empty, were put in motion at the summit of an in- 

 clined plane, at about 30 miles an horn', and were allowed to descend freely. 



2. Trains of carriages, loaded, were tried in the same way. 



3. The engine and tender were treated in the same way, being put to a 

 velocity of between 30 and 40 miles per hour, and allowed to descend freely 

 the whole length of the inclined plane without any train attached. 



4. The engine and tender, with a train attached, were propelled to the top 

 of the inclined plane, and then allowed to descend freely by gravity. 



By these means the following results were obtained ; — 



1. The resistance to railway carriages at slow velocities does not exceed 

 8 lb. per ton. 



2. The resistance to a light railway train of six carriages, at 23'6 miles an 

 hour, was 19 lb. per ton. 



3. The resistance to a loaded train of six carriages, at 30 miles per hour, 

 was 19 lb. per ton. 



4. The resistance to a light train of sue carriages, at 28 miles an hour, was 

 22 lb. per ton. 



5. The resistance to a loaded train of six carriages, at 36 miles an hour, 

 was 22 lb. per ton. 



6. The resistance to a six wheeled engine .md tender, at 23'6 miles an 

 hour, was 191b. per ton. 



7. The resistance to a six wheeled engine and tender, at 28-3 miles an 

 hour, was 22 lb. per ton. 



8. The resistance to a train composed of six light carriages, with engine 

 and tender, at 32 miles an hour, was 22 lb. per ton. 



9. The resistance to a train composed of nine loaded carriages, with en- 

 gine and tender, at 30 miles an hour, was 221b. per ton. 



From these experiments Mr. Russell drew several deductions, one of which 

 was that a train, when coupled with the engine, met with less resistance than 

 when put in action singly. He observed that the subject was at this time of 

 considerable importance, inasmuch as the system adopted for laying down 

 the gradients of new lines was of necessity regulated chieHy by the opinion 

 of the engineer on the question of resistance. How much mechanical force 

 is required to move a given weight of train, along a given gradient, at a 

 given speed, was a question of which the solution was essential to sound en- 

 gineering, but the profession had long felt that they were not in possession 

 of sufficient practical data to determine this question. 



In answer to a question from Dr. Green, Mr. Russell said that a large por- 

 tion of the resistance no doubt was due to the atmosphere, but still, allowing 

 for that, there remained a wonderful increase over the above supposed resist- 

 ance of about 8 lb. per ton, and the object of these experiments was to 

 learn from what cause that increase arose. 



Mr. Roberts hoped, in future experiments, the size of the wheels would be 

 taken into consideration. Both he and Mr. Fairbairn were of opinion that 

 if the wheels were made more cylindrical they would give a more comfort- 

 able action to the carriages. 



On the Great Fountain at Chatsworth, erected by the Duke 

 OF Devonshire. — By Mr. Paxton. 



This fountain is supplied with water from a reservoir which covers eight 

 acres of land, and which receives the waters from the moors. A hundred 

 thousand yards of earth have been cut away for this reservoir, and 2621 feet 

 of piping, having 29H joints, have been constructed for conveying the water. 

 The fall of the pipe is 381 feet, and the height which the water attains from 

 the fountain, (or which it is expected to attain when the whole work shall 

 have been brought into full operation,) is 280 feet, or, as the chairman ob- 

 served, about 60 feet beyond the bigliest point of York Minster. The de- 

 scription of this fountain was given as applicable to the study of hydrostatics, 

 showing the friction of water upon pipes and the impediment to its free 



course by friction against the air. One gentleman observed, with reference 

 to the force of water thus emitted that the sensation produced by putting a 

 finger in the pipe was just like that which would be experienced by putting 

 a finger into the flame of a candle. 



Report on a IIydrogen Furnace for Vitrification, and other 

 Applications of Heat in the Laboratory. — By the Rev. W. V. 

 Harcourt. 



At the request of the British Association Mr. Harcourt had undertaken 

 some years since to make experiments on vitrification. Dr. Faraday, in his 

 experiments on glass, had the greatest difficulty in procuring perfectly homo- 

 geneous masses, arising in most cases from the almost impossibility of pro- 

 curing a regulated heat in the ordinary furnaces. Mr. Harcourt, impressed 

 with the advantages which might be gained for optical purposes, by procur- 

 ing glasses formed by other salts and bases, instituted some experiments with 

 a view of ascertaining this point. It was considered, that if a tribasic phos- 

 phate formed a glass, and the bibasic phosphate formed a glass, we should 

 have, in all probability, glasses having different optical properties. Finding 

 difficulty in proceeding with these experiments, at the heat given by ordinary 

 furnaces, and the risk to which the platina crucibles were exposed, he was 

 induced to try the effects of hydrogen burning in common air. Dr. Dalton 

 was consulted on the construction of the first hydrogen furnaces, and he 

 suggested the difficulty which was found to arise in practice— that hydrogen 

 gas burning, through small orifices, with great pressure, would blow itself 

 out. This difficulty was, however, overcome in the management of the ap- 

 paratus brought before the Section. This apparatus consisted of an iron 

 tube, in which the gas was generated by the addition of 15 ounces of zinc to 

 three-quarters of a pint of oil of vitriol and ten pints and a half of water. 

 The gas produced was found to be in ten minutes imder a pressure of 21 

 atmospheres, in sixteen minutes and a half under a pressure of 2.'j atmo- 

 spheres, and in eighteen minutes under a pressure of 26 atmospheres. The 

 gas was conducted into another cylinder, and from thence to the jets, over 

 which was suspended a platina crucible. The gas being ignited at these jets, 

 maintained, with the above charge, the platina crucible at a white heat for 

 twenty minutes. Gems had been fused by the heat thus generated. Several 

 kinds of jets were used, as it might be necessary to surround the crucible 

 with heat, or only to apply the heat to the bottom of it. Experiments with 

 this apparatus have been made upon the phosphates of antimony, zinc, ba- 

 rytes, and cadmium. The results have not been, however, quite satisfactory. 

 In some the strice interfered with the transparency of the glass formed ; and 

 in the case of the monobasic phosphate of zinc, it was found that, to what- 

 ever heat the compound may have been exposed, the glass thus formed was 

 deliquescent. The reading of this Report was accompanied by some expe- 

 riments with the hydrogen furnace in question, for the purpose of showing 

 the intense heat which coidd be produced. 



Dr. Faraday bore testimony to the advantages of this arrangement. He 

 had found in all his experiments on glass, in which the elements were chemi- 

 cally combined, that crystallization took place. He regarded all common 

 glass as examples of solution, rather than of chemical combination. Borate 

 of lead and silicate of lead, if fused in small quantities, so that they cooled 

 quickly, were transparent, but if fused in masses, which required a longer 

 time, they were in a crystalhne condition. — Mr. Harcourt remarked, that in 

 the monobasic phosphate of zinc, which was transparent when vitrified, the 

 quantity of acid was probably exceedingly small, but this glass was striated. — 

 Dr. Faraday said, that some of the purest speciiuens of American ice show 

 similar stria;, although it was in a state of exceeding purity, yielding the 

 purest of all water when liquefied. — Some remarks were then made by Mr. 

 Pearsall, on the action of hydrogen on platina. An experiment was named 

 by Mr. Harcourt, in which a platina tube was destroyed by an attempt to 

 fuse ultramarine in it. Prof. Mebig stated, that pliitina was soon fused if 

 exposed to a charcoal fire, from the action of the silicon contained in the 

 charcoal. 



TiDAi. Observations. 



The Astronomer Royal gave a verbal account of the results of tide 

 observations on the coast of Ireland. For the purpose of these observations 

 stations had been established at different places on the coast, and the obser- 

 vations had been continued two months, namely, from the 22d of June to 

 the 25th of August. There were four critical periods daily in the tides, 

 namely, high water twice, and low water the same, one of which, at least, 

 must occur in the night, and it was necessary that these periods should be 

 watched. They were requisite, in order that proper allowance might be 

 made for the diurnal tides, because, at some of the stations, the forenoon 

 tide was higher than the afternoon, and again on the contrary. The plan, 

 therefore, was that about an hour before high water the observer began to 

 watch the water every five minutes, and watched it at those intervals until 

 it had decidedly taken a turn the other way. The same process was con- 

 tinned at the time of low water, and the observations were continued at 

 night in the same way. The result was that it was found the tide along the 

 S. and S. W. coasts was simultaneous, and along the west and north and 

 north-east, it was the same, but at the south-east there was a difference of 

 six hours. At Portadown, there was scarcely any tide at all, or the tides 

 flowed so frequently that it had been impossible to make an observation. It 



