page 161 note * The best way to familiarize one's self with the working of these scales, and the others to be described, is to cut a piece of cross-ruled paper into strips, number them appropriately, and then move them about into various positions,

page 164 note * A small scale in this form—so small as to be only a toy—has recently been published under the name of “Saxon & Co.'s Automatic Calculator.” The author of the directions furnished for its use has fallen into some extraordinary errors in describing the instrument, with whose properties, indeed, he seems to have some acquaintance, but neither with its name nor its underlying principle. He says, “It will be observed that the space between 1 and 2 is larger than any of “the others and that there are more lines subdividing that interval [which is “true enough]. The intervals between 2 to [sic] 3, 3 to 4, are alike [which is “obviously incorrect] and larger than the following ones, which do not differ in “size from each other” (!) One would have thought that his eye would have shown him the incorrectness of these statements, even although his knowledge was insufficient to reveal their inherent absurdity.

page 166 note * The setting out of the table in a single column of ten subdivisions, instead of the usual double column, was suggested to me by my friend Mr. James Chatham, and possesses many advantages.

page 179 note * Erskine Scott's book may sometimes be employed with tolerable ease in drawing up Sinking Fund Tables, and will give good results when each instalment is under £100. can hardly ever amount to ·02, so that the first step will not require more than one page to be turned over, and as the process is a continuous one the difficulty of finding the position of the multiplicands will not arise. If each tenth value be first calculated by way of check, the position of the anti-logarithm may be more accurately adjusted at these points.