The Emission of Smoke and Steam,
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How Trouble may be Avoided.
Attention has been drawn more than once in the pagrs
" THE COM Si SIKCIAL MOTOR within the last low months to the periodic activity of certain local authorities who endeavour to secure convictions against owners of steam wagons on the ground that their boilers do not " consume their own smoke." Summonses for such prosecutions are, as a rule, taken out tomer the )878 Locomotives and Highways (Amendment) Act, the police arguing that a steam motor wagon is no longer a light locomotive within the meaning of the emancipatory Act of /896 if it emits smoke or exhaust steam from the funnel. in the first section of this Act a light locomotive is defined in a curiously negative manner as one which does not exceed three tons in weight unladen (now increased to. five tons), and which does not emit smoke or visible vapour " except from any temporary or accidental cause," The police argue that any continuous emission of smoke or steam causes the steam wagon to be no longer a light locomotive, but to be a traction engine. It is very doubtful if such a general contention would be upheld by a judge, but magistrates, before whom such cases are heard, are not, as a rule, qualified to decide on the legal aspects. The Motor Van and Wagon Users' Association is, therefore, anxious to take a test case on this point, and to get the decision of a divisional court of the King's Bench as to whether such convictions are legal or nat. . The Association, with this object in view, is watching every case that comes before stipendiary magistrates or other justices; but no case will by taken to the High Court unless it is good, and one in which the issue is not likely to be obscured by any doubtful points in the evidence, or by any side issues__ The following instance of persecution is little short of amazing, and is certainly exceptional. It is a particularly interesting case, because the alleged emission of smoke was due to the block in Piccadilly, the roadway being then under repair, the stoppage causing loss of draught and deadening of the fire. Messrs. W. J. Lobjoit amid Sons, the well-known market gardeners of Hounslow, who have a service of tractors running between their farms and Covent Garden, were summoned quite recently, under the 1878 Act, for that they were " owners of a locomotive that was not constructed so as to consume, as far as possible, its own smoke, Ore." The case was heard at the Marlborough Street Poiice
before Mr. Denman, the stipendiary magistrate. Mr.
.Obj0ii, Itili IL ELLEIy, took objection to the fact that the summons was issued under the Traction Engine Act, and the magistrate decided to amend the summons and to hear it as it breach of Section r (definition clause) of the /896 Act. The magistrate decided to inflict a fine of 405o and argued that the words " temporary or accidental " must be read together, and that the block in Piccadilly is always more or less permanent, and could not. be urged as an excuse. It is a pity that this case is not to be taken further, because there can be no doubt that the decision is quite illegal and contrary to both the spirit and loiter of the Act; further, there is no power to impose tines for any breach of this particular section of the 696 Act. In view of the risk of groundless prosecution to which the owners of steam motor vehicles are liable, it is important that they should make themselves acquainted with the precautions that can be taken to prevent the emission of smoke or of visible vapour. It should be sufficient, in most courts, to show that a vehicle is so constructed as to consume its own smoke, but evidence must be given as to the :taloa construction of the essential parts. A short, illustrated description of the usual devices employed to prevent the creation of smoke, and the emission of visible vapour, will not, therefore, be inappropriate. It must be understood that " to consume its own smoke " is an entirely legal phrase, and is a mechanical and physical impossibility : all that can he done is to prevent the creation of smoke; once it has been produced it cannot be consumed! A bright red fire will cause no smoke, because all the volatile parts of the coal have been driven off, arid nothing but solid carbon is left. As the air passes through the fire bars, the oxygen combines with just so much carbon as is chemically required to create either carbon monoxide or carbon dioxide, both of which are colourless gases. When, however, fresh fuel is necessary, the cold coal is put on the top of the hot tire, and is really " baked " for some little time. During this baking all the volatile hydro-carbons are driven off as gases. If a sttearn of air is brought in contact with these gases; while they are at a sufficiently high temperature to burn, they \ill be consumed thoroughly and efficiently. On the other hand, if only a small supply of air reaches these gases they will decompose, the hydrogen combining with the oxygen to form water, and minute particles of solid carbon being freed in the shape of smoke. Oxygen has a much greater affinity for hydrogen than for carbon, and consequently it combines with hydrogen in preference. In order to make the matter quite clear, let it be put this way : if no oxygen reaches the gases which are given off by baking coal, they will leave the chimney as unburnt coal gas— the equivalent of "retorting " in a gas works; if a very small quantity of oxygen reaches these hot gases, the hydrogen in them will be burnt, whilst the carbon in them will take the form of smoke; if a sufficient supply of oxygen reaches the gases, they will be entirely and smokelessly burnt. With the conditions ruling in a steam wagon fire-box, simple destructive distillation never results, as some unconsumed oxygen is sure to find its way through the lower layers of the fire, and this decomposes a little of the gas and causes some smoke. it is, therefore, obvious that some means must be taken to ensure a better supply of air directly smoke becomes visible at the top of the funnel. The usual practice is to open the fire-hole door, and to regulate the admission of extra air by the amount to which this door is opened. When the motor wagon is in motion, the exhaust steam which discharges through the funnel will draw a much greater supply of air through the fire, so that, by applying the coal in small quantities at short intervals, the air will be found sufficient for combustion; but directly the engine stops, this induced draught ceases, and it is then that the extra supply of air through the fire-hole door must be given. There is a further provision in the shape of a supplementary steam jet in the funnel, which can be turned on to induce a draught when the engine is not running. Fig. z is a sectional elevation of an ordinary locomotive type boiler, show
" Advertising is the soul of business," a fact which is gradually making itself felt in France, though other countries arc far ahead. For some years the highly artistic posters which are displayed on walls and the luminous signs daily growing more numerous have tended to demonstrate that French commerce is following the example given abroad. Hitherto only the methods current in other countries have been employed, but now a French firm has invented what is styled a printing automobile. We were already acquainted with the car furnished with tyres bearing an inscription in relief and inked by a roller above the wheels, which printed an advertisement on the ground as it travelled. The firm in question, however, has done yet better; it has turned out a car that prints a complete poster The " Courrier du Livre " describes the ingenious method employed. An automobile breaks down and a curious crowd assembles : each individual is prepared to make the usual unsympathetic comments. The chauffeur desperately works levers and valves ; everything seems in order, and, after a toot of the horn, away he goes. Then, on the spot lately occupied by the car, a more or less artistic poster is seen, multi-coloured at discretion, which members of the public read with open mouth. There is an ink vessel under the car, and a series of pointed distributing tubes, from the orifices of which the ink falls, drop by drop, over the ground. These tubes are arranged so as to form the letters of the advertisement ing the position of the exhaust pipe and steam jet. This figure shows the notched bar which holds the latch of the lire-hole door in any required position, to provide for the admission of such a quantity of air as the coal requires according to circumstances. Fig. 2 is a plan of the same boiler, and the fire hole door is shown open to the second notch. The notched bar (or its equivalent) for the fire-door latch and the steam jet are appliances "so constructed" and fitted to a steam motor wagorp as to enable it "to consume its own smoke." Every steam wagon owner should see that these two details are on his wagons, arid should have drawings of them ready for production should he be summoned for emitting smoke. This is the strongest rebutting evidence that can be brought or show that the locomotive is "so constructed as to consume. its own smoke." The open fire-hole door is a remedy that must only be applied in " homceopathic " doses; sufficient air must be admitted to complete combustion, and no inure. If to much is admitted, the products of combustion are cooled, so that they cannot communicate much heat to the boiler, and the cold air striking against the tube plates will have a tendency to cause the joints to leak. When to open the door, and when to apply the jet, are questions that circumstances alone can decide; but, as a general rule, opening the fire-hole door reduces the generation of steam, and turning on the jet increases it. The question of exhaust steam is really quite separate from that of smoke, but a study of the cases that have been brought into the police courts shows that the English policeman is even incapable of distinguishing between black smoke and white exhaust. In some cases where white "visible vapour" has been the sole cause of offence, the policeman has sworn that dense volumes of black smoke were emitted. It will, therefore, be seen that, though the owner may be convinced that the sole cause of complaint had relation to visible vapour, he must be prepared to contest it as a smoke case. A further article will serve, at an early date, to illustrate the devices that are employed to render the exhaust steam invisible, and thus to arm those interested on all these points.
or a design, and are worked by a suitable mechanism, by aid of which they can be opened or shut at will. This ink vessel is moveable, and it can be lowered or raised. To print, the car is stopped; the ink vessel let down; and the valves opened. The drops soon spread and blend together, forming a clear print. The ink container is then raised, and the car moves away to print another poster elsewhere.— Cosmos.
We note that the Austrian postal authorities have at length awakened to the disadvantages of adhering to horse haulage in face of the gigantic strides of motor transport within the past quinquennium. A few days back, at the instance of the Minister of Commerce, Count Auersperg-, a meeting of interested parties (amongst them members of the Austrian Automobile Club and leading representatives of the trade) was held in Vienna, the object being, as explained by Count Auersperg-, an exchange of views on the subject. The Post Office, on the one hand, desired to know what class of vehicles the makers could deliver, and, on the other, offered to state the kind of van they could use. As a result of the conference, it was decided to employ electric motors for work within the city boundaries, and light benzine cars and vans for the suburbs and outlying country districts. It appears that the Post Office has already mapped out a number of routes, and a second conference will be held shortly,