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.
After the two standards, quarters, vamps, or other parts have been obtained, lay them on a sheet of suitable paper to make a stencil - marking the largest pattern first. After the larger pattern has been marked out, put the smaller one in such a position as to be readily distinguished from the one first marked, and trace that also round as shown in Fig. 149. Similar points on the two patterns must now be connected with lines. If the positions of taking the measures be marked on the two standards, this will not afford any difficulty. If the grading be for two parts, such as Wxyz in Fig. 149, then the corners should be connected as shown, producing them as xXO and zZO, meeting in point O. The point of intersection will give the centre for making radial lines for the whole of the back x to z. In a similar way the centre is found for the curve between w and y. After the lines are joined that may be considered sufficient for the purpose, the distances between the same positions on the two patterns will be sub-divided into as many equal parts as there are sizes intervening. See Xx, Fig. 149 ; also tT in the same figure.
The One-Sixteenth System of grading is supposed to be a system whereby a sixteenth of an inch is put round the pattern, leaving the extra on the toe to make the necessary addition to the pattern's length. When cutting out, the various alterations are made to make it approximately correct by keeping the knife either to the outside of the line or by cutting under where the increase is too great.
It depends, therefore, upon the individual judgment of the user, and is on this account to be depreciated. To obviate this leaving-on and taking-off business, several modifications have been and are used, one of which consists in using spring dividers set to distances of 1/16, 13/48, 5/48. This will be for the data: one size in length, 1/4 in. girth, and the ankle being equal to the joint.
Take the compass set to 1/16, and from the top of the leg with this distance mark as far as the throat; at the throat mark with the other compass 5/48. From the throat to the toe mark 1/16. Put 1/16 along the top, down the back, and along the bottom. Leave 13/48 at the toe.
The sixteenth system leaves the patterns the same length from the top of the leg to the throat, giving the patterns a stumpy appearance for the large sizes, while the smaller sizes look too long. The joints are also out of position, and the instep does not alter its position for the various sizes. This error is known among many of the users of the system, and it is defeated by various means, one of which is given under.
Take 1/16 in. in the compasses and mark up the front, along the top, down the back, and from the seat to the joint. Add one size less 1/16 to the toe of the graded standard. Join toe to the joint. Place standard pattern half size away from toe of the newly marked one and correct the joints. Raise the standard 1/32 at the seat from the marked seat and mark the back, or 1/64 is left on the swell above the counter. Leave 1/64 from the top of the instep to throat, graduating to the front of the leg. Leave 1/32 on the front of the leg, and if the top be curved or volute leave 1/32 on the front curve and 1/32 in front of the back curve.
The One-Fifteenth System is very similar to the one described, and it consists in taking one-fifth of a size (1/15 in.) in the compasses and then marking that amount round the top, back, bottom, and up the front. Add one size less 1/15 in. to the toe, correcting the joints in a way similar to the one described above.
To grade vamps on these systems make a line 1/16 from a folded piece of paper, and mark 1/9 at the right-hand end. Take the vamp to be graded and put the front level with the 1/8 mark, while the toe is level with the crease of the paper, then lower the throat of the vamp 1/16 and mark the half-wing. Put half-size to the length of the wing and complete the curve, using the standard to get the bottom portion.
There are many Shifting Systems of grading in use in different localities being employed by the empiric.
In the first method the curves of the pattern are marked upon the standard at each centre, and a line ruled from the toe to the counter. The pattern is then taken and traced on a sheet of paper, and the line from the counter drawn as in the standard. One-ninth of an inch is added at the heel end of the toe-counter line, and 2/9 in. at the toe end. The grade used is 1/9 at the joints, 5/36 at the instep, 1/6 at the heel, and 1/9 at the ankle. These amounts are divided and placed to the credit of the respective parts. The pattern is completed by using the standard to connect the various points.
Hannibal's is another type of shifting system, and is described in his work upon "Last Fitting and Pattern Cutting " something as follows :The standard pattern is taken and lines ruled upon it at the joints, toes, instep, heel, and ankle. A line is also drawn from counter to toe. On this horizontal line from the toe two separate 1/9 in. are marked. From the toe end 1/4 in, is also marked. The standard is now placed upon a suitable sheet of paper, and the three dots in the standard marked through on the paper. While the standard is in this position mark round as far as the toe-line top and bottom. Shift the pattern towards the heel, so that the first dot on the paper is visible, and while doing this lower the back until the toe at the first mark is level with the traced outline. When in this position mark from the top of the toe-line to the joint. Now shift the standard until the second dot appears, lowering the back until the first on the toe touches the traced line. Mark from joint to instep. Again shift the standard until the third dot appears. While in this position mark from the instep to the top of the leg. Trace also the top. Shift again until 1/12 in. is shown from the throat to the top of the leg. Trace down the back as far as the ankle, then lower the standard, trace the back as far as the horizontal line. Lower the standard until the distance of § in. is shown at the instep, keeping the toe in line with the toe of the traced outline. Mark the bottom to the instep. Shift the pattern to the second dot and trace from instep to joint. Cut out if satisfactory.