Answers to Queries.
Page 21
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Deliberate Use of Water in Cylinders of Internalcombustion Engines.
[4017] (Hants.).—No motorcar or motor lorry has ever been driven, other than experimentally, by a mixture of water and petrol; the success has never been commercial, and has in fact never satisfied even the inventors theinselves ; the only method which offers success is a pressure feed of steam, or very hot water under pressure through a valve opening and closing during the mid-portion of the compression stroke ; the specific heat' of dry steam is approximately 0.5,. and the heat required to superheat such dry steam is insignificant in comparison with the total heat available in the cylinder.
Use of Gas-retaining Cotton Bags to Hold Coal-Gas.
[4018] (Intending Users).—You can buy the finished article from Messrs. Andrew Barton Bros., Beeston, Notts., inclusive of the needful lashings and connections. You may find the following suppliers of use to you in the matter of proofing cotton fabrics, so as to give them gas-retaining properties :—
Chas. Macintosh and Co., Ltd., Cambridge Street, Manchester. Messrs. James T. Inglis and Sons, Riaeraide 'Works, Dundee. • Thos. Briggs, Ltd.., 11, Chatham Street, Salford, Manchester.
W. II. Heaps, Ltd., West -View Mills, Littleborough.
Water Rights Where a Ford Previously Existed.
[4019] (Steam-wagon Owner).—We fear that your contention-is not sound. Rights which were enjoyed when the stream was crossed by a ford ceased when the stream was bridged. We are legally advised that the position is this: when the stream was crossed by a ford the public proceeding along the highway had the right of access to it, but such access was taken away when the highway was carried over the stream by means of a bridge. In general terms, unless a. person has access to the water, he is not entitled to use it.
As regards your further point of taking water from a running stream, the fact that one owner of the land adjoining both the banks higher up has no objection to any infraction of his rights does not• entitle you to claim that a second such owner. but one lower down would have none. Technical trespass is committed in taking water from a running stream by means of a hose pipe. Each riparian owner is entitled to the flow of water past his property, subject to the rights of the riparian owners above.
Road Performance from One Gallon of Petrol.
[1020] (Puzzled).—You are not the only user who is at a loss to understand the conflicting records of many users in respect of performance on the road, per gallon of petrol, expressed in gross ton-miles. The smaller types of cominerM motors, say, up to 25 cwt. in load capacity, freqaently fall so low as 30 cross ton-miles per gallon of petrol. There is an improvement as a general rule, as vehicles of greater load. capacities are considered,. going so high, under favourable engine and road conditions, as even 75 gross ton-miles per gallon. Experience with and knowledge of records of all kinds, all over the country, satisfy us that an average figure of perfprmance is 50 gross ton-miles per gallon, but any such figure must be viewed in relation to the age and general condition of the vehicle by which it is contributed, the class of roads, both gradients and surfaces, and the weather conditions, including the velocity and direction of the wind, during any trial run or other test for the purposes a record.
One gallon of petrol may be taken to contain 140,000 British Thermal Units (the unit of heat being the amount necessary to increase the temperature of 1 lb. of water by 1 degree Fahrenheit). On multiplying 140,000 B.T.V. by 778 (Joule's mechanical equivalent of heat, in foot-pounds), one gets a total of 108,920,000 foot-pounds as the work value in one gallon of petrol. We might, had we space at our disposal, work out a number of examples to show the relation of particular per formances to the maximum heat value of a gallon of petrol, but we content ourselves by presenting two examples, the known data being from actual cases of user : — (1) For practically fiat country, and with no addition for wind resistance: traction at road wheels, 40 lb. per ton ; add for occasional gradients, an aveaage of 10 lb. per ton ; add for transmission losses, 6 lb. per ton ; gross weight of vehicle, five tons ; distance run per gallon, 10 miles ; recorded performance, 50 gross ton-miles per gallon; 50 ton.miles equals 264,0110 ton-feet, and this multiplied by 56 lb. (for total traction) yields a total work done, on the one gallon of petrol, of 14,784,000 footpounds. This is equal to 13.6 per cent, of the total heat in the petaol, and is not a good case, due to the evident lowness of the average engine-load factor. '
(2) For a run in country of moderate gradients, assuming that the gradients are equivalent to 1 in 20 for a quarter .of the distance, and with no addition for wind resistance: traction at road wheels, 40 lb. per ton ; add for gradients, 28 lb. per ton ; add for tranamisSion losses. 7 lb. per ton ; gross weight of vehicle, 10 tons ; distance run per • gallon, 7 miles ; performance, 70 gross ton-miles per gallon.; 70 ton-miles equals 369,600 ton-feet, and this multiplied by 75 lb. (for total traction) yielas a total of work done, on the one gallnn of petrol, of 27,720,000 foot-pounds. This is equal to 25.5 per cent. of the
total heat of the petrol, and is a good case. , The above percentages express the relationship of the power transmitted from the clutch to the total energy in the fuel.
To, Carry 12 Tons at 5 m.p.h. in Lancashire.
[4021] (Haulier),—A 25 h.p, oil or electric tractor would be necessary for the haulage to which he refers. We know of no electric tractor on the market for such work, apart from the fact that there would be serious likelihood of running the batteries down before the end of a40-mile journey. Of course, if a "boosting" charge, Or a complete charge, could be given in the course of the day's work, that difficulty would be avoided, but. it does not get over the fact that noelectric tractors have up to the present been marketed. When a tractor is used to haul a trailer, the legal maximum speed is 5 m.p.h. The chief disadvantage, as compared with a motor lorry which carries part of a load on its own platform, drawing a trailer behinCit, is the lesser platform area of the trailer, no load going on the tractor. Only cao trailer can be drawn -under, the Heavy Motor Car Order. If two 'trailers be drawn, in the present state of the law, the combined working unit is tree ted as a locomotive, under the Act of 1898, sand is subject to traction-engine law, inclnsive of an annual licence or 210 for the first county or county'borough through which it works, and an additional annual Iicenee cf 25 (or alternatively 2s. 6d: a day) for each additiensd county or county borough through which it works. if motor lorry and trailer be used, under the Heavy Motor Car Order, there is an initial•paynient of 21 for registration, and no annual payment. We are inclined to think that, for the class of work about which you write, it would be better to purchase a steam wagon and trailer, using it for. a 104on load, divided between the two carrying platforms.