If this be, as is probable, a general rule for areas and speeds considerably different from the above, to find the quantity of air blown into one or more furnaces by the fan, we should calculate the volume by one of the above formulæ (1) or (2), and take 4-fifths of the result, as the true quantity.
The fan A C here represented is of the best excentric form, as constructed by Messrs. Braithwaite and Ericsson. D is the circular orifice round the axis by which the air is admitted; and C C B is the excentric channel through which the air is wafted towards the main discharge pipe E.
FOUNTAIN; a stream of water rising up through the superficial strata of the earth. See [Artesian Wells].
FOXING, is a term employed by brewers to characterize the souring of beer, in the process of its fermentation or ripening.
FRANKFORT BLACK; is made by calcining vine branches, and the other refuse lees of the vinegar vats in Germany. They must be previously washed.
FREEZING. (Congelation, Fr.; Gefrierung, Germ.) The three general forms, solid, liquid, and gaseous, under one or other of which all kinds of matter exist, seem to be immediately referrible to the influence of heat; modifying, balancing, or subduing the attraction of cohesion. Every solid may be liquefied, and every liquid may be vaporized, by a certain infusion of caloric, whether this be regarded as a moving power, or an elastic essence. The converse of this proposition is equally true; for many gases, till lately styled permanent, may be liquefied, nay, even solidified, by diminution of their temperature, either alone, or aided by a condensing force, to bring their particles within the sphere of aggregative attraction. When a solid is transformed into a liquid, and a liquid into a gas or vapour, a quantity more or less considerable of heat is absorbed, or becomes latent, to use the term of Dr. Black, the celebrated discoverer of this great law of nature. When the opposite transformation takes place, the heat absorbed is again emitted, or what was latent becomes sensible caloric. Upon the first principle, or the absorption of heat, are founded the various artificial methods of producing cold and congelation.
Tables, exhibiting a collective view of all the Frigorific Mixtures contained in Mr. Walker’s publication, 1808.
I.—Table consisting of Frigorific Mixtures, composed of ice, with chemical salts and acids.
Frigorific Mixtures with Ice.
| MIXTURES. | Thermometer sinks. | Deg. of cold produced. | |||||
|---|---|---|---|---|---|---|---|
| Snow, or pounded ice | 2 | parts | From any tem- pera- ture | - | to -5° | * | |
| Muriate of soda | 1 | ||||||
| Snow, or pounded ice | 5 | parts | to -12° | * | |||
| Muriate of soda | 2 | ||||||
| Muriate of ammonia | 1 | ||||||
| Snow, or pounded ice | 24 | parts | to -18° | * | |||
| Muriate of soda | 10 | ||||||
| Muriate of ammonia | 5 | ||||||
| Nitrate of potash | 5 | ||||||
| Snow, or pounded ice | 12 | parts | to -25° | * | |||
| Muriate of soda | 5 | ||||||
| Nitrate of ammonia | 5 | ||||||
| Snow | 3 | parts | From +32° to -23° | 55 | |||
| Diluted sulphuric acid | 2 | ||||||
| Snow | 8 | parts | From +32° to -27° | 59 | |||
| Muriatic acid | 5 | ||||||
| Snow | 7 | parts | From +32° to -30° | 62 | |||
| Diluted nitric acid | 4 | ||||||
| Snow | 4 | parts | From +32° to -40° | 72 | |||
| Muriate of lime | 5 | ||||||
| Snow | 2 | parts | From +32° to -50° | 82 | |||
| Cryst. muriate of lime | 3 | ||||||
| Snow | 3 | parts | From +32° to -51° | 83 | |||
| Potash | 4 | ||||||