A patent was recently issued in England for an invention which consists in so constructing coke ovens that they shall be in communicating pairs, the waste gas and heat from each oven being made to surround, or partially surround, its fellow, by means of flues, [before passing into a chimney or the open air, so that by charging each oven composing a pair alternately, neither is allowed to get cold, and it is said that by this process the operation of coking is carried on with greater economy and expedition. It is preferred that the ovens be placed in pairs, back to back, but this ob- servance is not indispensably necessary.