What is more admissible is that with one heat and in the same machine an operation could be performed on the two faces perpendicularly. The bar could then be taken from one furnace and put in another immediately, to pass at once to another machine to again undergo the operations following. The work could then be done rapidly, submitting the bar to several heats.
The most important principle to note, and on which the different machines employed are designed, is this: The punches or matrices acting on the chain at its different points of progress are put in motion by spiral springs worked by means of tappets or cams distributed over the circumference of a cylinder, having a rotary movement imparted to it by pulleys and belts.
The figures on our plate show with sufficient clearness the working of one of these machines. It will be seen that the bar traverses through and through the machine for stamping, and that it can be disengaged for a reheating before passing to subsequent operations.
The bog peat of Mexico is now being used on a considerable scale as fuel for locomotives, stationary engines, smelting purposes, smiths' fires, and househould use. The peat is mixed with a proper proportion of bitumen, and is said not only to burn freely, and without smoke in much quantity, but to give a higher dynamic equivalent of heat than the same amount of wood.
[Footnote: _The Brewers' Guardian_, from the _Zeit. f. d. gesammte Brauwesen_.]
Little that is definite is known of the substance or substances to which the hop owes its bitterness. Lermer has succeeded, it is true, in separating from hops a crystallized colorless substance, insoluble in water, an alkaline solution of which has a marked bitter flavor, and which easily changes on exposure to the air, assuming a resinous form. According to Lermer, the formula of this substance is C_{ 32}H_{ 50}O_{ 7}; it possesses the properties of a weak acid and forms a characteristic copper salt, which is soluble in ether. This hop bitter is, however, produced from the hop by a very roundabout process, by treatment of the extract with alkalies; it is not therefore regarded by many as present in this form in the hop, and they hold that it is only produced by the action of the alkalies. On the other hand, however, Etti, by a complicated extracting process, but without using an alkali, succeeded in producing a bitter substance from hops, which is, however, soluble in water.