“The true and the most serious inconvenience of steam-engines is the smoke. It is against this that most of the well-founded complaints are raised.
“This inconvenience is not only felt at the present moment, but it excites, above all, apprehensions for the future.
“When we consider that in the single year 1839, there have been granted 82 authorizations for steam-engines, and that we are yet but at the beginning of the applications of this mechanical agent,—when we follow the increasing progression of petitions addressed to the administration, we are not able to suppress a certain fear against the ulterior invasions of the smoke from these establishments.
“The council have applied themselves for a long time to the solution of this difficulty, which is met at every turn in the petitions addressed to you, not only for steam-engines, but for all the trades in which furnaces are employed.
“Various systems have been proposed: that which first presents itself is the use of smoke-consuming furnaces, which appears in fact the most rational and appropriate. Nevertheless, although it is very easy to assign the theoretical conditions for complete combustion of coal, the difficulties of application have not permitted this kind of furnace to become general. Hitherto the smoke-consuming furnaces require great precision in the execution, great regularity in the distribution of the fuel,—things difficult to realize in ordinary labour. On the other hand, the great excess of air necessary to obtain complete combustion often diminishes the efficacy of the coal, and renders these furnaces more expensive, in certain cases, than the ordinary furnaces, in spite of the loss of fuel which the latter involve.
“The mechanical distributors to regulate the supply of fuel, and the activity of the combustion, have been also proposed and employed with success; but they are a considerable expense at the outset, and can be but little adopted except in great concerns, and where there is a very constant application of steam.
“It remains to modify the nature of the fuel; and it is this which the council have generally done. They commonly prescribe the use of coke, or some variety of prepared coal, which gives no smoke—leaving it however to the proprietors to make use of whichever method suits them best, whether smoke-consuming furnaces, mechanical distributors, or fuel which yields no smoke.
“These regulations, Monsieur le Prefect, have been adopted in principle by the “Conseil de Salubrité,” and are, in the majority of cases, the condition to which they think it their duty to submit the authorizations they have the honour to propose to you.
“Doubtless their rigorous application may cramp certain establishments. The council are not ignorant that for some particular purposes the use of coke presents great obstacles, considering the construction of the furnaces; but the absence of smoke in the combustion of coal is not so very difficult to obtain, as to shake the intimate conviction of the council that this constriction will be but momentary, and that it will end by turning to the profit of the manufacturer.
“The problem of which the council seek the solution, is able to be resolved; it is so already in great part, but there yet remains one step to arrive at the goal, and they will reach it by persevering in the course they have adopted. In their efforts they have been sustained, we repeat, by the conviction that they labour not only for the advantage of the health and cleanliness of the capital, by seeking to guarantee its inhabitants from the nuisance of smoke, but also for the advantage of the manufacturer himself, by forcing him to a better employment of his fuel, and by putting him into such a condition that he may be able to select the localities which suit him, without being exposed to those continual complaints, to those recriminations, often well-founded, which have not always been foreseen, and which sometimes become the cause of the greatest embarrassments to the manufacturing establishments.