Transcriber’s Note
Inconsistent spelling and hyphenation have not been standardised.
The calculations in the text regarding the number of combinations and permutations have been transcribed without further comment, even when they might be open to discussion.
The reference letters and numbers given in the descriptions of illustrations are not always present in these illustrations, but they may be present in other illustrations of the same object.
Page 33, S S, O O, Z Z, are ornaments fastened on at b c d: this does not appear to be in accordance with the illustrations.
Page 153, footnote [11]: these figures are not present in this book.
Page 164: “As no complete list ...: the closing quote mark is missing.
Page 164 ff, table, entry 1784: the date column was blank in the source document.
Changes made
Footnotes have been moved to under the paragraph in which they were referenced.
Where necessary, parts of the hatching or other details in illustrations have been removed to make reference letters (better) visible.
Page 9: closing quote mark inserted after "curious knot".
Page 45: "receptacles at C d" changed to "receptacles at c d".
Page 48: fig. 23 was printed upside-down in the source document.
Page 51: "the notches f or g in the bolt" changed to "the notches s or g in the bolt", cf. fig. 26.
Page 57: "the notches n n" changed to "the notches n n´".
Page 77: "shewn at a a in fig. 37" changed to "shewn at a´ a´ in fig. 37"; "3, 2, 3" changed to "3, 2, 3´".
Page 89: "T the third" changed to "T³ the third" cf. illustration.
Page 100: "piece of metal h p" changed to "piece of metal h h" cf. illustration.
Page 104: "ged" changed to "get".