Howard, of Luton, invented a press on similar lines, but the action was horizontal instead of vertical, this served a very good purpose for a period until MM. Desbordes,[2] of Paris, introduced their hydraulic press. This consisted of a steam heated chamber in which was placed the metal “pan” or “dish,” it being the “female” mould of the required shape. The pressure was obtained by an overhead chamber to which an india-rubber bag was fastened. This chamber was very strong and heavy, and was, as it were, one end of a balance, working on trunnions, at the other end of which were two large metal balls as counterpoise. To bring into operation, the chamber was pulled down so that the centre of the india-rubber bag, which was made with a teat, came into the crown opening of the pan; the chamber was securely fastened by means of screw lugs to the portion holding the pan, and a hydraulic press was put into action which filled the rubber bag with a sufficient pressure of water to distribute the power all over the hat in the pan; a gauge showed the pressure obtained and consequently an equal amount could be given to every hat. The results, therefore, were all alike, and as the press could be locked and unlocked in a fraction of the time required by the screw process, the work was greatly accelerated. Many improvements have been made in blocking machines since then (about 1860), but all the later models embody the important feature of the hydraulic pressure through the rubber bag. The next important step in the evolution of mechanical blocking was that introduced by Mr. Henry Keston, of Luton, adapted from a model made by a Mr. Beresford, of Stockport, Cheshire. This improvement consisted of erecting round steel uprights on the bed of the steam heated chamber, allowing the bag chamber, attached to which were slides fitting the uprights, to rise and fall vertically. The counterpoise was effected by a chain, attached to the top of the bag chamber, passing over a wheel supported by a bracket at the back of the machine and loaded with sufficient weights to adjust the balance. A hand or foot lever pressure was sufficient to raise or depress the bag chamber, and water connection to it was obtained by means of a corded re-inforced india-rubber swan neck. When the chamber had descended to its proper position it was locked by means of a stout steel three-armed part like the hub of a wheel, with three spokes radiating from it at equal distances. The hub was pivoted on the centre of the top of the bag chamber, and a short lateral movement of this part brought all three spokes under very strong hook-like lugs, and locked the bag chamber securely to the pan chamber. [Illustration: Fig. 18 MACHINE BLOCKING By Press of Beresford-Keston Type]