Rate 1 cent for each 4 ounces or fraction. Full prepayment required. No limit of weight.
_Third Class_ includes unsealed books, newspapers and periodicals not admitted to the second class, circulars, miscellaneous printed matter on paper not having the nature of personal correspondence, and proof sheets, corrected proof sheets, and manuscript copy accompanying the same, engravings, lithographs, seeds, scions, cuttings, bulbs, roots, and plants. Also facsimile copies made by a mechanical process such as the printing press, electric pen, mimeograph, hektograph, copygraph, etc., provided that they are mailed at the post-office window in the minimum number of twenty identical copies separately addressed. If mailed elsewhere or in less number, first-class postage is required.
A circular may have in writing therein the name of the addressee or sender or date.
Corrections in proof sheets include the alteration of the text and insertion of new matter, as well as the correction of typographical and other errors. They include also marginal instructions to the printer necessary to the correction of the matter or its proper appearance in print. Part of an article may be entirely rewritten if that be necessary for { 131} correction. Corrections must be upon the margin of or attached to the proof sheets. Manuscript of one article cannot be inclosed with proof or corrected proof sheets of another except at the first-class rate. Written designation of contents, such as “book,” “printed matter,” “photo,” is permissible upon the wrapper of mail matter of the third class.
A single card bearing the written name and address of the sender, or an envelope bearing a written or printed name and address of the sender, may be inclosed with a circular, catalogue, or other third-class matter without affecting the classification thereof. Public library books, otherwise mailable at the third-class rate, may bear any printed or written mark which may reasonably be construed as a necessary _inscription_ for the purpose of a permanent library record.
Rate 1 cent each 2 ounces or fraction. Limit of weight, 4 pounds, except single books. Postage must be fully prepaid and great care exercised not to add any written words or figures except such as are permissible.