In the original of this work, most pages are headed by a topic phrase, so that a topic can be located quickly by riffling the pages of the book. In this etext, the same topic phrases appear in right-aligned boxes near the text that begins that topic. Thus a topic can be found by scrolling the text and scanning the right margin.

The many images of the original are inline here as grayscale graphics in PNG format, scaled to 480 or 512 pixels width. When an image has a pale-gray border, the reader can click on the image to open a higher-resolution version.

In the original, the requirements of book design often caused the editors to place images some distance from the text that discussed them. In this etext some images are placed closer to the point where they are mentioned and thus not at their original page number. Each image has a number, for example f016. In the List of Illustrations and the Index, references to images by page number have been replaced by these figure numbers, which are linked to the images. Within the body text, references to a figure by its page number are linked to the image, not the specified page.

Two minor typos were corrected: thing to think on page 10 and intregal to integral on page 197.