Transcribers note: Many of the puzzles in this book assume a familiarity with the currency of Great Britain in the early 1900s. As this is likely not common knowledge for those outside Britain (and possibly many within,) I am including a chart of relative values.
The most common units used were:
| the Penny, | abbreviated: d. (from the Roman penny, denarius) |
| the Shilling, | abbreviated: s. |
| the Pound, | abbreviated: £ |
There was 12 Pennies to a Shilling and 20 Shillings to a Pound, so there was 240 Pennies in a Pound.
To further complicate things, there were many coins which were various fractional values of Pennies, Shillings or Pounds.
| Farthing | ¼d. |
| Half-penny | ½d. |
| Penny | 1d. |
| Three-penny | 3d. |
| Sixpence (or tanner) | 6d. |
| Shilling (or bob) | 1s. |
| Florin or two shilling piece | 2s. |
| Half-crown (or half-dollar) | 2s. 6d. |
| Double-florin | 4s. |
| Crown (or dollar) | 5s. |
| Half-Sovereign | 10s. |
| Sovereign (or Pound) | £1 or 20s. |
This is by no means a comprehensive list, but it should be adequate to solve the puzzles in this book.