One of the first acts I perform when I receive a manuscript electronically is to find-and-replace double spaces with single spaces. It takes only a few seconds and it removes all those unnecessary gaps between words that will only irritate me and make me lose focus on the actual manuscript as I read through it. The double space after the period is a holdover from the days of manual typewriters, when it was somehow deemed necessary to show people that the sentence had come to an end and a new one had begun, as if the round splodge after the last letter of one sentence and the big capital letter beginning the next sentence weren’t enough. I consider the double space a relic of a more unhurried, and perhaps less literate age, akin to the pre-eighteenth-century custom of placing at the bottom of the page the first word of the next page (known as the “catchword“—from which we get our modern-day idiom), so that bookbinders would keep the pages in the right order. The double space following a period is particularly unnecessary, since not only is the book likely to be edited, thus potentially changing sentence structure, but the whole book is going to be retypeset, thus rendering the manuscript’s original typesetting moot. Justification of the text so that no text is ragged right or left will also render your attempts to control space useless. Double spaces after periods aren’t the only quirks of manuscript layout that are wholly unnecessary: 1. Providing page numbers in your table of contents. All the pages will change anyway. Just put “00” or “000” if you want to indicate that the page number should be inserted. 2. Macro “anchors” that take you from the table of contents to a particular chapter. This is very annoying to the editor who reads a manuscript electronically and a complete waste of time if the manuscript is printed out to be perused. 3. Wild and crazy margins, exotic and/or unreadable fonts in a range of colors, ridiculous point sizes for the text, and anything else showy and superfluous. The point of your submission is to make your manuscript as undemonstrative as possible to guarantee that nothing—and I mean nothing—gets between you and the editor’s meeting with your first sentence.