In the case of porter, the initial heat of which is 64° F. or 17·8° C., the temperature in the vats sometimes rises to 78° F. or 25·5° C.; but such an increase in temperature excites considerable apprehension. We have seen a tun for pale ale, containing 200 barrels of 36 gallons, pitched with 600 lbs. of fairly solid yeast. In forty-six hours the attenuation was considered sufficient, and the beer, which from an initial heat of 58·1° F. or 14·5° C., had risen to 72° F. or 22·2° C., was cleansed to working casks. The large vats in which the fermentation is started may be considered as equivalent to the _cuves guilloires_ of French breweries, the casks in which it is completed and the yeast thrown off representing their 75-litre vessels, improperly called _quarts_. Notwithstanding the enormous English beer manufacture, and although the fermenting vat, as in making porter, for instance, sometimes attains the capacity of 2,000 to 3,000 litres (400 to 600 gallons), the casks into which it is run are never larger than 15 to 20 hectolitres (300 to 400 gallons); and even at Burton, in the celebrated breweries of Allsopp and Bass, the pale ale is finished in casks of a capacity less than 10 hectolitres, and yet the average turn-out of these immense works reaches 3,000 to 4,000 hectolitres (60,000 to 80,000 gallons) of beer per day. Footnote 7: [The expressions “high” and “low” fermentation or beer strictly refer to temperature, whereas the other expressions used (“top” or “bottom”) refer to the behaviour of the yeast. The French words _haute_ and _basse_ seem to look both ways.—D. C. R.] Footnote 8: It is said that the floating cones or cylinders filled with ice, which enable brewers to manufacture beer at a low temperature, even in summer, were first used in Alsace. Footnote 9: 45 million kilos. of ice are annually consumed in the brewery of M. Dreher, in Vienna. The brewery of Sedlmayer, at Munich, uses about 10 million kilos. (_Journal des Brasseurs_, 22nd June, 1873.) Footnote 10: It should, however, be borne in mind that these remarks on the relative preservative powers of the two beers hold true on account of three things—differences in the respective modes of brewing, artificial cooling during the process of fermentation, and the storing of the “low beer” in ice-cellars. In itself, perhaps, “low beer” is more liable to change than “high beer;” that this does not actually take place, is due to the employment of artificial cooling. A brewery which has an average annual production of 10,000 hect. will use 8,000 cwt. of ice. If we add to this the ice used during the retail of the beer, which is best drunk at 12° C. (54° F.), we shall arrive at the total of 100 kilos. per hectolitre. Footnote 11: