During the past few years the science of winning wealth from slaughter-house offal of every description has made enormous strides, effort having been concentrated upon the recovery of the very utmost yield of by-products for the simple reason that the demand therefor is exceedingly keen, while prices are necessarily attractive. This applies particularly to the fats, the value of which ranges up to as much as £50 per ton, according to grade, although other commodities simultaneously secured, such as meal for cattle-feeding and fertilizers, are able to command equally impressive prices. A graphic idea of the degree to which this science has been advanced is obvious from the dimensions, comprehensiveness and modernity of the by-product installations which have been laid down as adjuncts to the mammoth cattle-killing plants in various parts of the world, the majority of which, as I have pointed out in a previous chapter, are of British origin, design and construction, and many of which have been, and still are being, supplied from this country. Surely it is somewhat anomalous that other countries should come to us for the latest expressions of ingenuity and invention in this province when we are unable to point to a single pretentious plant in this country! At the same time it is distinctly gratifying to learn that if Britain cannot display sufficient imagination or commercial acumen to use plants of this character, she certainly can build them, and is not only able to keep well astride of the times, but is fertile in thought concerning a highly specialized ramification of industry.