H.L. Mencken (1880–1956). The American Language. 1921.VIII. American Spelling
7. Minor Differences
There are also certain differences in punctuation. The English, as everyone knows, put a comma after the street number of a house, making it, for example, 34, St. James’s street. They usually insert a comma instead of a period after the hour when giving the time in figures, e. g., 9, 27, and omit the o when indicating less than 10 minutes, e. g., 8, 7, instead of 8.07. They do not use the period as the mark of the decimal, but employ a dot at the level of the upper dot of a colon, as in 3.1416. They cling to the hyphen in such words as to-day, to-night and good-bye; it begins to disappear in America.
There remains a class of differences that may as well be noticed under spelling, though they are not strictly orthographical. Specialty, aluminum and alarm offer examples. In English they are speciality, aluminium and alarum, though alarm is also an alternative form. Specialty, in America, is always accented on the first syllable; speciality, in England, on the third. The result is two distinct words, though their meaning is identical. How aluminium, in America, lost its fourth syllable I have been unable to determine, but all American authorities now make it aluminium and all English authorities stick to aluminium. Perhaps the boric-boracic pair also belongs here. In American boric is now almost universally preferred, but it is also making progress in England. How the difference between the English behove and the American behoove arose I do not know. Equally mysterious is the origin of the American snicker, apparently a decadent form of the English snigger.