1. The period is used at the end of every complete sentence which is not interrogative or exclamatory.
2. Sentences interrogative and exclamatory in form, sometimes take the period.
Will you call at my office, say on Tuesday next, or whenever you happen to be in town, and much oblige—
How much better it is, considering the saving of distance to the pupils, that two small schoolhouses should be built, rather than one large one.
3. The period is put after initials when used alone; also after abbreviations.
4. Place a period before decimals, and between pounds and shillings.
5. A period should always be put after roman numerals, except when used in the paging of prefaces, etc.
George III. came to the throne in 1760.
OBSERVATION 1. In many modern works the period is omitted; as,—
William I made a mistake.
There being no comma after “William,” it is supposed to be obvious that the mistake was made by William the First. The insertion or omission of the period is becoming wholly a matter of printing-office style.