SMOKE ; SMOKE-PREVENTION. 



SNOW. 



630 



be obtained from a given quantity of fuel, at the same time that the 

 nuisance of smoke would be abated. It may be observed, that the 

 quantity of smoke emitted from furnace-chimneys varies much with 

 the state of the fire, being greatest when a mass of fresh fuel is thrown 

 on, and least when the fire has burned clear or the fuel is fully ignited. 

 Attention to this circumstance, on the part of the stoker, will greatly 

 diminish the nuisance ; because, if he throw on the fresh fuel in a thin 

 layer, it will the sooner become perfectly ignited ; and, by laying it in 

 the fore part of the furnace, the dense smoke arising from it has to 

 pass over that part of the fire which is in a state of more perfect com- 

 bustion, and is thereby in a great measure consumed. Many of the 

 contrivances introduced or suggested as smoke-consuming furnaces act 

 on these principles ; arrangements being adopted to insure the right 

 feeding of the fire without much attention on the part of the firemen. 



James Watt was one of the first to obtain a patent for a smoke- 

 consuming or smoke-preventing apparatus. He caused the smoke of 

 the fresh fuel, in its way to the chimney, to pass, together with a 

 current of fresh air, over fuel which had ah-eady ceased to smoke, and 

 was intensely hot ; by which means the smoke, by coming into close 

 contact with the hot fuel, and being mixed with the current of 

 fresh air, was converted into pure flame, free from smoke. Since 

 that time innumerable plans have been brought forward for intro- 

 ducing the necessary supply of air to the furnace ; but while many 

 of them accomplish the purification of the smoke as completely 

 as could be desired, many others increase the consumption of fuel 

 or weaken the draught of the furnace. If the air admitted to the 

 furnace be cold, it diminishes the heat of the fire ; and if hot, expense 

 ia incurred in heating it, whether this be effected by a separate fire or 

 by passing the air in pipes through the chimney. Most railway com- 

 panies are required, by their acts of incorporation, to avoid the emission 

 of smoke from their engines ; and this is usually done, at great expense, 

 by the use of coke. To lessen this expense, Mr. Chanter devised a plan, 

 consisting in the introduction of a dtjlector dipping into the burning 

 fuel, which compels the smoke from the crude coal to pass through a 

 ma of burning coke, supplied through a small door, and conducted at 

 once to the back of the furnace. By this means three parts of coal 

 may be used to one of coke, with very little risk of much smoke. 



Another mode of destroying smoke is by injecting steam into the 

 furnace. The plan has been tried by several inventors, among others 

 by Mr. Iveson. In his apparatus, the steam is thrown into the fire in 

 several minute jets, from a fan-shaped distributor in the fore part of 

 the furnace. The steam not only destroys the smoke, but also greatly 

 increases the intensity of the fire. Thus the necessity for a large 

 chimney is obviated, it being only necessary to provide a small passage 

 for the escape of the gaseous products of combustion. Experiments 

 on the same furnace, with and without the injection of steam, indicate 

 a saving of fuel to the amount of 33 per cent. ; the consumption in 

 five hours being respectively 558 and 812 Ibg. As a drawback from 

 this saving, the plan requires, in a steam-engine furnace, about one- 

 tenth of the steam generated, and in other furnaces renders necessary 

 the erection of a small boiler. It ia proposed, in high-pressure engines, 

 to make use of the watte steam for the purpose of injection. 



Besides the numerous plans for the combustion of smoke, various 

 method! have been tried on a limited scale for conducting it to dis- 

 tance from the buildings in which it is formed, by means of subterra- 

 neous channels ; and for condensing it by means of a shower of water 

 so that the sooty matter might be conveyed away by the sewers. 



In 1819, a committee of the House of Commons was appointed " to 

 inquire how far it may be practicable to compel persons who use 

 steam-engines and furnaces in their different works to erect them in a 

 manner less prejudicial to public health and comfort." The committee, 

 in their Report, noticed, among other plans, that of Mr. Steel, in which 

 the fuel was supplied in a constant stream, by means of an inclined 

 hopper ; the quantity of coal supplied in a given time, and the size of 

 the pieces, being regulated by a grooved roller. The fuel was distri- 

 buted over the bed of the furnace by the motion of the grate itself, 

 which was of a circular form, and turned on a central pivot. The 

 comniitttt, alter much investigation, reported that efficient means for 

 destroying smoke had been " satisfactorily and effectually obtained." 

 An act of parliament was passed to enforce the use of smoke-consuming 

 apparatus ; but it was very little attended to, and the smoky condition 

 of our great towns increased quite as rapidly as the increase of popu- 

 lation and manufactures. After many years had passed, the Commons 

 appointed another committo; of inquiry in 1843. This committee 

 examined a large number of scientific and practical men, among whom 

 were Dr. Faraday, Dr. Arnott, Professor Brande, Dr. Ure, Admiral 

 Parry, Dr. Reid, Mr. Jukes, Mr. Solly, Mr. Muntz.and Mr. Houldsworth. 

 Nearly all concurred in opinion that smoke may be nearly prevented, 

 either by existing methods or by apparatus easy to devise. Voluntary 

 wociatioiu had been formed in many large manufacturing towns, 

 ""fading Leeds, Bradford, and Manchester, to put down the nuisance! 

 In numerous factories there was a positive saving of fuel effected by 

 the avoidance of smoke ; but most of the manufacturers declared that 

 the apparatus hitherto employed had not fulfilled the promises made. 

 The committee recommended an act of parliament, but none was passed 

 at that time. In 1 841, before the Health of Towns Commission, Mr. Thos. 

 : (than whom few men were more thoroughly versed in the philo- 

 sophy of house-building) advocated smoke-prevention very energeti- 



cally, as being practically attainable, morally obligatory, and financially 

 profitable. Another committee sat in 1845, followed by an attempt to 

 pass a smoke-prevention act ; but this was frustrated by certain 

 influential manufacturers, who did not like the trouble attending the 

 adoption of new apparatus. When the Health of Towns' Act was 

 passed, clauses were introduced which empowered town-councils to 

 attack the smoke nuisance in their own way, and within the limits of 

 their own towns ; and many places availed themselves of this power 

 After other minor attempts at legislation, acts were passed in 1853, 

 1856, and 1857, rendering it compulsory to adopt smoke-preventing 

 contrivances. Two of these acts related to the metropolis and one to 

 Scotland. Certain trades were exempted from the operation of the 

 statutes, and certain dates were named on which the penalties for non- 

 observance would begin to be enforced. Not only furnaces employed 

 in trades and manufactures, but also steam-boats working above London 

 Bridge, were brought within the scope of the acts relating to the metro- 

 polis. The police received certain powers in relation to this matter 

 and the pro visions of the acts were sought 'to be enforced by penalties. 

 Improvements have resulted from these legislative enactments ; but 

 the evil is still far from being removed. There seem to be difficulties 

 attending the enforcement of the law. Those manufacturers, whose 

 furnaces are arranged on the old plan, protest against the expense 

 necessary for adapting the smoke-preventing apparatus ; and they are 

 not slow to declare that the several inventions fail in some or other of 

 the requisite conditions. On the other hand, the statements are most 

 clear and positive that the evil can be prevented, and that a saving in 

 fuel rewards those who resolutely make the attempt. Printers, woollen 

 spinners, builders, metal-founders, button-makers, sugar-refiners, steam 

 corn-millers, porter brewers all have placed upon record the declara- 

 tion that gain as well as cleanliness results from the adoption of 

 smoke-preventing apparatus. 



We.shall make no attempt to describe the numerous forms of appa- 

 ratus patented within the last few years. All of them belong to one 

 or other of two classes. They attempt either smoke-consumption, by 

 supplying the heated smoke, at a particular spot, with fresh air enough 



f~* o 'vj i* j-i viviucu .->JMII,, wil/U lit .ML ail CUUUlTll 



to kindle and consume it ; or smoke-prevention, by so supplying fuel 

 that it may ignite without forming smoke at all. T ' ' 

 belongs to the latter class. 



The inventions of Dr. Arnott would call for some attention here, 

 were it not for the fact that his ingenious stoves and ventilating appa- 

 ratus had better be described under WARMING AND VENTILATION, 

 in connection with many other kinds of apparatus for similar 

 purposes. 



SMUGGLING is the clandestine introduction of prohibited goods, 

 or the illicit introduction of goods by the evasion of the legal duties. 

 Excessive duties present an overwhelming temptation to men to evade 

 them ; and the law loses a great part of its moral influence when it 

 first tempts to violation of it and then punishes the offence. The true 

 remedy is a wise tariff. It annihilates at once a traffic which no inge- 

 nuity can ever put down ; for all experience proves that so long as a 

 profit can be made by smuggling sufficiently high to counterbalance 

 the necessary risk, it will not fail to flourish. The decrees of Berlin 

 and Milan, instead of annihilating commerce, only forced it into extra- 

 ordinary channels. Silk from Italy, for example, instead of being 

 received in England by the most direct means, often arrived by way of 

 Archangel and Smyrna ; in the former instance being two years, and 

 in the latter twelve months, on its passage. Sugar, coffee, tobacco, 

 and cotton-twist were despatched from England to Salonica, and thence 

 conveyed by horses and mules through Servia and Hungary to Vienna, 

 from which place they were distributed over the Continent, in defiance 

 of the rigorous decrees of Napoleon ; it might happen that coffee was 

 consumed at Calais which, instead of being sent direct from London, 

 arrived by the above circuitous route. 



We have only to examine the tariff of any country to know if 

 smuggling is practised ; and if a bad system of commercial policy has 

 been long pursued, there the smuggler will be found. The contra- 

 banduta of Spain figures in novels and tales of adventure. In no 

 country is the illicit trade so general and extensive. The exports to 

 Gibraltar from England are very large, and a great proportion is intro- 

 duced by smugglers into the interior. Nearly the whole of the tobacco 

 imported into Gibraltar is smuggled into Spain, where the article is one 

 of the royal monopolies. On the French frontier the illicit trade is ' 

 equally active. 



The vicinity of France and England, and the injudicious character 

 of their respective tariffs, long encouraged smuggling to a large extent 

 on both sides of the Channel. 



The reduction of the duties on silks, tea, spirits, wines, and numerous 

 other articles, has done more to repress smuggling than all the efforts 

 of the revenue officers aided by a large armed force. 



The present acta relating to smuggling are 3 & 4 Wm. IV. c 53 and 

 4 & 5 Wm. IV. c. 13. 



SNOW. It has been stated [RAIN, vol. vi. col. 925] that rain, snow, 

 and hail are formed by the precipitation of vapour when two volume* 

 of air of different temperatures, and saturated with moisture, become 

 mixed together; the nature of the precipitation depending on the 

 resultant temperature and on that of the region of the atmosphere 

 through which the aqueous particles descend towards the ground. 

 Now when the precipitating water is frozen into crystals of ice, 



