Quadrat

Quadrat (pronounced kwod-ruht)

(1) In ecology, an area of vegetation (sometimes as small as one square metre), marked out for study of flora and fauna in the surrounding area; the frame used to mark out such an area.

(2) In printing, a blank, low-cast type used by typographers to fill in larger spaces in printed lines.

(3) In civil engineering, a type of surveying instrument (obsolete since the sixteenth century).

(4) In Egyptology, a virtual rectangular subdivision of a line or column of hieroglyphs within which a group of hieroglyphs is arranged.

1675-1685: From the late Middle English quadrate, from the French quadrat (literally "a square") from the Latin quadratrus, past participle of quadrare (to make square) and related to quadrus (a square), quattuor (four); the ultimate root was the primitive Indo-European kwetwer- (four).  The earlier use in English (certainly as quadrate but there are indications the spelling quadrat was also used although this may be a later error in transcription) dates from circa 1400 and described a type of surveying instrument.  Quadrat is a noun; quadratic is an adjective and quadrically is an (irregular) adverb; the noun plural is quadrats.   

For pedants only

English is known for its grammar Nazis but there are also style Nazis, one of their concerns being whether there should be one or two spaces after a period (full- stop).  While its quite possible most neither notice nor care, obsessives in both factions feel strongly about this and Microsoft’s April 2020 update for Word users on the 365 platform (the old Microsoft Office 365), which included a new rule flagging double spacing as an error, triggered a minor twitterstorm.

The debate actually goes back centuries, mono and double spacing between sentences, sometimes within the same document, existing from the earliest days of mechanical printing and it’s a myth it has anything to do with proportional fonts.  Proportional (variable width) typefaces were created hundreds of years ago but by the nineteenth century, the double space between sentences was the usual practice in commercial publishing, a standardisation (in English) reinforced during the era of the typewriter (1880s-1980s).  Except for a tiny number of (initially very expensive) IBM machines (from 1942), typewriters universally used monotype typefaces, every character, regardless of shape, taking the space of an upper case M.  The two spaces between sentences became the standard for typists because it made the text easier to read, a practice which endured even after most commercial publishing had, by the mid-twentieth century, adopted single spacing.

Unlike typists, mechanical typesetters weren’t limited to the monotype.  However, the upper case M remained their baseline which came to be known as the “em”.  Units of space were developed as specific fractional segments based on the em, a linear measurement equal to the point size of the typeface. In 10 point type, the em is 10 points wide; in 12 point type, 12 points wide etc.  There were four ubiquitous spaces, thick, middle, thin, and hair, the thickest of which was less than an en (an en being half of an em).  When more horizontal space was needed, typesetters turned to the quadrat (from the Latin quadrates (squared)).  These precisely sized typographic blanks were used for indents, larger spacing, the creation of white lines, and the filling up of short lines and existed in printers’ jargon as en, em, two-em, three-em and four-em although, when setting poetry, special quadrats were sometimes cast to ensure the proper alignment of uniquely set lines.

Below are two examples of the first paragraph of IMDb's biography of Lindsay Lohan, rendered in a monotype font which emulates the output from a classic mechanical typewriter; the upper sample uses single spaces after each period, the lower two spaces.  The comparison illustrates (1) how the double-space between sentences was helpful with monospace typesetting because it so assisted readability and (2) how with proportional fonts the difference is probably so marginal as to be imperceptible to all but a trained (or obsessive) eye.

Microsoft’s 365 update is optional, those committed to the double space can switch off the rule but there’s little doubt the single space is now the more popular practice.  Neither is right or wrong and research about which renders text more readable has been inconclusive, proving only that the factions seem set in their views.  One finding from the research however was that most readers seemed not to care one way or the other; most not noticing even when both methods were applied even within the same paragraph.