302 



General Notices. 



sheep, swine, or poultry; and, consequently, that the mixing together of the 

 manures made by different animals will generally be found to increase fer- 

 mentation. 



Finally, if, in any part of Great Britain, there should be a quantity of 

 such materials as, in France, would be made into manure by Jauffret's pro- 

 cess, the shortest and most economical way would be to mix them with 

 horse-dung, as practised in forming meadow-bank middens. In this way, 

 one load of horse-dung might be made to ferment hundreds of loads of 

 other fermentable matter. 



Joyce's new Mode of Heating. — When we noticed Mr. Joyce's stove in our 

 January No., p. 57., the nature of the fuel was an entire secret. It since turns 

 out to be nothing more than charcoal prepared in a particular manner, which, 

 though it deprives it o^ its smell, and, perhaps, diminishes in some degree its 

 deleterious properties, yet leaves it of the same nature as it was before, though 

 not so perceptibly dangerous, from its want of any noxious fffluvium. Mr, 

 Joyce's stove, therefore, has entirely failed in realising all the high expect- 

 ations that were formed of it, and cannot be recommended, either for plant- 

 houses or human habitations. The manner in which the charcoal is deprived 

 of its smell is said by some to be by boiling it in any alkali, such as lime-water ; 

 and this may afford a useful hint to gardeners, where they are under the 

 necessity of using a charcoal stove in fruit-rooms or plant-houses, on extra- 

 ordinary occasions. 



Dr. Arnoti's Stove. — Our opinion of this stove, as expressed p.l54., remains 

 unchanged ; and we still believe it to be the very best of all stoves for an ill- 

 built cottage, in which the windows and doors are so badly fitted as to admit 

 abundance of air. For the rooms of well-built houses, however, where the 

 windows and doors fit tightly, and where this stove is substituted for an open 

 fireplace, and no air allowed to pass up through the chimney, except what passes 

 through the stove, a distinct system of ventilation will require to be intro- 

 duced, to prevent any unpleasant feeling being experienced. We doubt very much 

 if such a system is practicable on a small scale, and therefore question whether 

 Dr. Arnott's stove will ever become a substitute for open fireplaces in sitting- 

 rooms of ordinary dimensions, as now constructed. That it is the best and 

 most economical stove for halls, staircases, and rooms, where there is an open 

 fireplace and a fire ke|)t burning, or, in short, wherever there is an efficient 

 means of ventilation, we have no manner of doubt. Its excellence consists in 

 the small proportion of the heat produced which is allowed to escape up the 

 chimney, and in never raising the outer temperature of the stove above that of 

 boiling water. How these two grand objects are effected will be understood 

 by the following diagram. 



" The outhne a b dc (fig. 41.) represents 

 a box formed of sheet iron, and divided by 

 the partition g h into two chambers, commu- 

 nicating freely at the top and bottom. The 

 letter e marks the fire-box or furnace, formed 

 of iron, lined with fire brick, and resting on 

 a close ash-pit, of which b marks the door, 

 and near which door there is a valved open- 

 ing, by which air enters, to feed the fire 

 when the door is shut ; i marks the door of 

 the stove, by which fuel is introduced ; c is _ 

 the chimney flue. While the stove door and 

 the ash-pit door are open, a fire may be e. 

 lighted, and will burn in the fire box just as i 

 in a common grate, and the smoke will rise 

 and pass away by the chimney, mixed with 

 much colder air, rushing in by tiie stove 

 door ; but, if the stove door and ash-pit door . 

 be tlien closed, and only as much air is " 

 admitted by the valved opening in the ash- 



