298 



SCIENTIFIC NEWS. 



[Sept. 14, it 



Mr. Fletcher asked Mr. Dowson whether he had contemplated 

 the possibility of saving the ammonia which would be obtained in 

 carrying out the system he had described. 



Major-General Webber. C.B., who said he had watched the pro- 

 gress and development of the matter in question with considerable 

 interest, did not think Mr. Dowson had given himself sufficient 

 credit for the results he had obtained. He had worked in the 

 direction of reducing nitrogen to a minimum without increasing 

 the expense of manufacture. In this process of manufacture 

 the apparatus converted the three fuels coal, water, and air into 

 the results which were given in the analysis. He had not 

 attempted to get rid of nitrogen, but to obtain the maximum 

 quantity of hydrogen, and he was very much to be congratulated 

 upon the effective mode he had adopted for the purpose. He 

 might justly be called the pioneer of gaseous fuel. In Paris in 

 1881 one of these generators was at work under the gallery during 

 the whole of the Exhibition, and it was not considered a source of 

 danger, nor yet of inconvenience, to the number of valuable ex- 

 hibits by which it was surronuded. The idea that danger would 

 result from placing the generator in the basements of buildings 

 in our towns was, therefore, entirely got rid of. The speaker de- 

 scribed the successful manner in which an engine driven by this gas 

 worked electric light machirery by night and farm machines by 

 day, in a countiy place where the expense of coal was too great for 

 steam to be used. Such a success as this was, in his opinion, worth 

 all 'he written evidence which could be placed before them. 



Professor Hele Shaw said that when the system was first de- 

 scribed at the British Association meeting at York, in 1881, he 

 asked a question as to whether if gaseous fuel were used for domestic 

 purposes serious danger might not possibly result where carbonic 

 oxide was used in large quantities. Mr. Dowson then replied that 

 he proposed, when using it foi such a purpose, to adopt means to 

 enable the presence of carbonic oxide to be detected. This was 

 another example of preconceiving a danger which might never 

 happen, for they had now the experience of several years at the 

 Gloucester Asylum and elsewhere to show that no inconvenience 

 resulted, and he congratulated Mr. Dowson on the result. He felt 

 certain that Mr. Dowson had given his figures honestly. He had 

 also always stated that lor an ordinary boiler this gas should not be 

 used. The suggestion that gas should be generated in the boiler 

 itself was a valuable one, and suggested a new departure. Water-g as 

 would then be employed in a most satisfactory and economical manner. 

 He asked for information as to the probable aggregate horse-power 

 of the engines now working with the author's gas. 



Mr. Williams asked whether any instances had been met with 

 in which danger had resulted from the use of this gas. The danger 

 from carbonic oxide was very great, and he had read of instances 

 in which it had caused death without there being any smell or other 

 indication of its presence. He understood that in the United States 

 its manufacture was on this account restricted by the law in several 

 parts of that country. 



Mr. Dowson, in replying, said he would be extremely sorry 

 to be in any way unfair to the steam-engines. All he desired to 

 do was to point out the [ different conditions under which they 

 worked when on trial and on ordinary occasions. Experimentally, 

 when he had worked the gas apparatus himself, he had brought 

 down the consumption of fuel to 1 1 lb. per indicated horse-power 

 per hour, but he had preferred to give the examples mentioned in 

 his paper, as they referred to engines doing practical work under 

 ordinary conditions. He thanked General Webber for his appre- 

 ciative remarks, but must be careful not to take more credit than 

 was his due. Sir William Siemens was unfortunately no longer 

 with them, but it must not be forgotten that it was mainly due to 

 him that the question of gaseous fuel had come prominently forward 

 in this country. In answer to Mr. Fletcher's question as to the 

 recovery of ammonia, he said he had not given the subject any 

 serious thought. The quantity of ammonia was infinitesimally small 

 when anthracite coal was used, so that it would hardly pay to recover 

 it. Mr. Dowson proceeded to say that he knew of no one injured 

 by this gas, and that it was no doubt a satisfaction to find that in 

 such an institution as the County Asylum at Gloucester, which pos- 

 sessed a competent medical staff, who were necessarily exacting about 

 the hygienic conditions, the use of this gas had been carried on for 

 five years without any trouble at all having occurred. In concluding, 

 Mr. Dowson acknowledged that there was a danger in the use of car- 

 bonic oxide, as there was also in using gunpowder, electricity, and 

 other things if they were improperly handled. All that was necessary 

 was to recognise the danger, and then take precautions accordingly. 



The President expressed his deep interest in the matter under 

 discussion, and congratulated Mr. Dowson on the success which had 

 attended his investigations. He added that up to the time of his 

 dea'h the late Sir William Siemens was actively engaged on the 

 subject, and the prize given by him at the Smoke Abatement 



Exhibition for the best method of utilising fuel was awarded to Mr. 

 Dowson. 



Monday, September iotk. 



Mr. W. H. Preece, F.R.S., presiding. 



The special subject for the day's discussion was Applied Elec- 

 tricity, and the first paper was read by Mr. W. Anderson, 

 M.Inst.C.E., upon The Application of Electricity to the Working 

 of a 2.0-ton Travelling Ctane. One of the travelling cranes in the 

 foundry of the Eiith Ironworks was originally constructed to be 

 worked by hand, but preparations had been made to apply wire 

 rope driving at some future time. 



The crane is 39' 6" span, and consists of a pair of wrought-iron 

 girders resting on end carriages running on an elevated line of rails. 

 The gearing for hoisting longitudinal and for cross traverse is secured 

 to the top of the main girders; the hoisting chain passes from the 

 barrel at one end over a pulley at the other, then back to the 

 pulleys in the cross traversing carriage, which runs between the 

 main girders, through a falling block, and thence to an anchorage 

 under the barrel at the extreme end of the main girders. By this 

 arrangement the crane occupies a moderate height, and the hook 

 can come within three feet of each wall. 



The inconveniences and wear attending the employment of rope- 

 driving gear induced the writer to try whether electricity might not 

 be used with advantage. Messrs. Elwell Parker, of Wolver- 

 hampton, were communicated with, and these gentlemen undertook 

 to supply the dynamo and a motor suitable for the peculiar require- 

 ments of a heavy crane. The dynamo, which was intended to give 

 50 amperes at 120 volts with 1,200 revolutions, was fixed in the 

 main boiler-house of the works, and was driven by a small hori- 

 zontal engine by means of a link belt. The leads from the boiler- 

 house up to the conductor in the foundry are of 6 B. W. G. copper 

 wire, while the conductor is formed of an angle-iron bar 2" x 2" x ^", 

 extending the whole 350-feet length of the shop, and has one face 

 roughly ground and protected from rust by vaseline. The return 

 current travels along one of the rails on which the crane runs. 

 The motor, which is shunt wound, and constructed for 100 volts 

 and 50 amperes, is fixed en the working platform of the crane 

 beside one of the main girders. Its driving spindle carries a steel 

 pinion which gears into a double helical spur wheel keyed on to a 

 shaft which runs longitudinally on the top of the girder, and is 

 connected by nests ot three bevel wheels, with friction clutch con- 

 nections to the three shafts which command the several movements 

 of the crane, the means of using the hand-power being still 

 retained . 



Two sets of speeds are arranged for each of the movements,, 

 namely — 



Hoisting . . slow 3 '4 ft. per min., fast 10 ft. per min. 

 Cross traverse . ,, 25 „ „ ,, 105 „ ,, 



Longitudinal traverse 78 ,, ,, ,, 213 „ ,, 



To provide against undue strains upon the motor an automatic 

 magnetic cut-out is fixed on the crane, and for the purpose of vary- 

 ing the power and speed to meet the requirements of the foundry 

 a set of resistance coils is provided, governed by a special switch by 

 means of which different resistances can be introduced into the 

 armature circuit of the motor, or the current can be cut off alto- 

 gether, but so that it must be done by steps, and not suddenly. 

 The connection between the motor and the conductors is by means, 

 of brushes pressed against them by elastic attachments. The 

 handles for operating the several movements, the break lever, the 

 switch, and the automatic cut-out are all collected together, so that 

 a single attendant can readily work the crane from one spot. 



The crane was set to work in June last, and has continued to act 

 satisfactorily ever since. The advantages are very great in the 

 facility of adaptation, as it is so easy to transmit the power fronx 

 any point. The main boilers being always under steam, the crane 

 is available at a moment's notice. The duty realised is about sixty- 

 five per cent, of the power developed in the driving steam-engine. 

 As far as can be judged at present, there is no special wear to 

 apprehend. The conductors act satisfactorily, though a considerable 

 length is in the open air, and the dust, heat, and smoke of the 

 foundry do not appear to affect the working. 



When first proposed, the writer' was not aware of the existence 

 of any other electric crane, but he has since learned that Messrs. 

 Mather and Piatt, of Manchester, have had one working satisfactorily 

 for some time, and that there is one also in France. 



A brief discussion followed. Several members, including Mr. J. 

 L. Stothert and Sir Frederick Bramwell, F.R.S., asked ques- 

 tions as to the details of the working of the crane, and in reply Mr. 

 Anderson said he thought there was not a weak point in it. The 

 crane worked perfectly well, and without the least tronb'e. 



