This section is from the book "The Manufacture Of Boots And Shoes: Being A Modern Treatise Of All The Processes Of Making And Manufacturing Footgear", by F. Y. Golding. Also available from Amazon: The Manufacture Of Boots And Shoes.
This tool is useful to aid the designing of a bespoke pattern, especially when the last from which the upper will be made cannot be obtained. Being based upon average, requirements, it may also be used when the last is obtainable, the additions or deductions being made to suit the special requirements.
The tool * is made of zinc, German silver, or aluminium ; ab is 13 in. long. At right angles to this be is made, c being 7 in. from b. The distance from b to X is 8 in., and from X to y 4 in. This will make y equal in length, when measured from b to size 11 adult's last. From b towards X divisions of 2/9 in. are made and numbered from 11 to 1, as shown in illustration. From 1/9 distances of 1/9 in. are made and numbered. The toe-line at a would make an angle of 50° with ah continued. T is situated one-shoe size (1/3 in.) from a. From T to the top is If in. The joint line from X is made at an angle of 65° to ab, and 31/2 in. in length. The curve C is the shape of the throat of an upper pattern. The edge L makes an angle of 95° with cb, and is 51/4 in. in length. The notches 34° to 45° are cut to make the angles that they indicate to the line ab from b. The curve S is a vamp-throat curve, and N the shape of a back of an average standard (see Fig. 141).
* It may be obtained from Messrs. Chapman & Hall.
Upon a suitable sheet of paper the constructor is laid, and the two lines cb ; ba, are drawn at right angles (Fig. 142). From b the height of the heel required is measured (making deductions are previously alluded to for the thickness of the forepart). The constructor is next placed so that the adult size 8 at the back of the marker is placed on the height of the heel marked. Keeping the division 8 in this position, lower the tool until Y reaches the base line ab. This is letter J (Fig. 142). The tool is made to coincide at Y with J, and the back portion is lowered to the base line ab, and the direction of the joint line indicated Fig. 143. "While in this position, the eight length is marked off from the front of the tool, and the tool moved backwards along ab until the bottom of the toe-line (see T, Fig. 141) is level with the 8, as shown in Fig. 143. The tool is next placed so that the corner b (Fig. 141) is on the height of heel position S (Fig. 144), and the base passes through J. The direction of the heel (here 42°) is marked off as shown in Fig. 144. The lines TJb; Js; sH; Tt; Jn; bsc in Fig. 145 will illustrate the stages now completed. The joint girth measure of the last, less width of the tread, is taken, and one-half marked from J to n. By taking one-half of Jn and measuring it from 0, the point t is obtained. From 8 the half-heel measure is marked toward H. The centre of Hs is indicated in X. Lines perpendicular to the base ab are drawn through H to F, and from X to 6. From X measure towards 6 the distance XH and point 2 will be found. The top edge of the tool (L, Fig. 141) is placed on 6 (the height of pattern required) and the edge (ab, Fig. 141) kept level with cb (Fig. 145). The line F6c is then drawn. This is repeated at point 2, and the line 1, 2, 3 drawn. The points 1 and 3 are found by using one-fourth of the ankle-girth measurement for either side of 2. From 3 to 4 measure a constant of half an inch. Connect 4 s. The centre of 4 s is point 8. One-half either side of 6 of the leg measure will give 5 and 7 (Fig. 145). The points may be connected by straight lines, as shown in the illustration, preparatory to the formation of the necessary curves. The instep position may be found by drawing the long-heel measure here at 34° to Js.