vapour pump, by which the ammonia formed by evaporation is exhausted from the refrigerator, compressed, liquefied, and forced into (3) the condenser, consisting of a multitubular vessel surrounded by water; (4) a circulating pump for supplying the condenser with water; (5) ice tanks surrounded by a bath of a liquid of a low freezing point, such as a solution of chloride of calcium or of common salt; (6) a circulating pump for circulating the brine through the refrigerator and around the ice tanks; (7) the steam engine or other motor for driving the vapour and circulating pumps. =Rope Making.=--[J. T. WRIGHT.]--(B. 578). Within the last few years a machine has been introduced by Mr. Good, an American, for treating fibres as imported, more particularly Manilla. By means of fluted rollers, and a system of bars fitted with strong steel pins which press upwards into the hemp, the fibres are dressed and straightened out, the operation is aided by a patented machine known as Wright and Laider’s Patent Sun and Planet Hacklebus. Finally, the hemp fibres are drawn off the pins and delivered in a compact and continuous sliver into a can placed in front to receive it. These slivers being in one length, are now passed on to the drawing frames to be accumulated together. =Steel Pen Trade.=--[MAURICE POLLACK.]--(B. 634.)--There has been little improvement since 1865. Muffles heated by gas on the plan of Dr. Siemens, have been introduced for tempering and colouring, and ordinary gas is also used in connection with these processes, but these improvements are only used by one or two firms, and more as a matter of convenience than as a means of making pens of a better quality or lower price.