A section of the gutter, as finished, is shown. To bring it into this form, after the timbers had been sawn into the requisite general dimensions they were brought under the action of the planing-machine, where they were planed on the four sides. This machine is patented by W. Furness, of Liverpool, and was worked at the Chelsea Wharf Saw-mills. The operation was effected by cutters (_a_) attached to the ends of an arm revolving with great rapidity in a horizontal plane; the timbers to be planed were wedged up into a frame (_b_) traversing on rails, and as this was passed under the revolving cutters the upper surface was removed by them, at the same time the timbers were held down upon the frame by a large iron disc (_c_) pressing upon their upper surface. The disc, together with the revolving arm carrying the cutters, was capable of being adjusted vertically to the exact dimensions of the timber. The traversing-frame was slowly propelled by the machinery, and three widths of timber were operated upon at one time. On leaving the planing-machine these quarter baulks were passed on to the gutter-cutting machine. Four different cutters were required to form the section, as shown above; they were placed one behind the other, so that the piece of timber, which was presented to their action above the centre of motion, passed over each of them in succession. The first set, which revolved in a vertical plane, roughly hollowed out the larger groove to the section shown in Fig. 1; the two next were counterparts, and formed the same section in opposite directions; they were set at an inclination to the upright of about 45 degrees, the one to the right, the other to the left; and each hollowed out one of the small side grooves, and one side of the larger gutter, leaving the section of the timber respectively of the forms shown in Figs. 2 and 3. Fig. 4 shows the form of its section after it had passed both; the fourth set of cutters again revolved vertically, and gave the gutter its finished form, as shown above. As the timber passed over the cutters it was supported at the ends on revolving rollers, and was held in its place by guiding grooves, being pressed gradually forwards against the cutters. [Illustration: SECTIONS OF THE DIFFERENT STAGES OF THE PAXTON'S GUTTERS.] [Illustration: THE GUTTER-CUTTING MACHINE.] In this manner forty-two lengths of solid gutter, each twenty-four feet and a fraction long, were completed in a day of ten hours; and as the machine was worked double time, a length of more than 2,000 feet was turned out daily ready for use: this, it has been calculated, would have required the labour of about three hundred men to be employed for the same length of time. The absolute necessity for such rapid production will be evident when it is known that no less than 110,000 feet, or about twenty miles length, of such gutters were required--very nearly the distance from Buckingham Palace to Windsor Castle.