Mechanical device, gear-trains, and arithmetic
A pen mechanism and red-chalk wheelworks with a worked multiplication.
A small pen mechanism appears at the middle left of the leaf, and a longer horizontal assembly of toothed wheels runs across the lower half. The captions name them a mechanical device (in pen) and wheelworks or gear-trains (in red chalk). The rest of the sheet carries numerals headed 'arithmetical operations', including a set-out multiplication of 31 by 90 giving 2790, with further partial sums grouped below.
On this page
Mechanical device
A small pen mechanism is sketched at the middle left of the leaf. The caption identifies it only as a mechanical device. It is a light study of linked moving parts.
Gear-trains (ruotismi)
A longer horizontal assembly of toothed wheels runs across the lower half of the sheet. The red-chalk caption names it wheelworks or gear-trains. It shows several rotating wheels engaged in a train.
Worked multiplication
Rows of numerals headed 'arithmetical operations' fill part of the leaf, including a set-out multiplication of 31 by 90 giving 2790. Partial sums and further figures are grouped below. They are ordinary calculating exercises.