ENVELOPE (OF. enroluper, enreloper, en relopper. Fr. envelop per, to enwrap). A paper covering extensively employed for inclosing let ters, circulars, pamphlets, and othe'r mail mat ter, and for an endless variety of other purposes. Envelopes began to be used in England and the United States in the decade from 1840 to 1850. In both countries their use for letter mail fol lowed the introduction of cheap postage. At first the blank forms from which envelopes are made were cut by hand to a pattern, and also gummed and folded by hand. The first practh cable machine for making envelopes was pat ented in England in 1844 by Warren De la Rue and Edwin Bill. In America the first patent was granted in 1849 to J. K. Park and C. S. Watson. The Di' la Rue machine was in many respects similar to the machines now in use, as described below; hut instead of gumming and lifting the blank in practically one operation the blank wits lifted by india-rubber fingers, then gummed by a separate arm.
Envelopes are now made entirely by nm•hinery, and their manufacture is a comparatively simple process, involving one operation. They are cut nut directly from a ream of paper. 500 at a time. or in larger numbers if the paper is thin. This is aecomplighed by a steain-driven See Dts:s AND DIE-SINNIN0). The blanks, thus cut, are automatically fed into the machine. where they are gummed. one by one, by the 'mutt picker; which is fed with gum by menus of rollers. and applied to the margin of eneh Hank. 1 Le hIlnh is next Parried on to the folding-hox, v. here folder, press down the four laps, but do not WO en done the upper one. The envelope is ion curried on by an endless chain, and during its tram-it I flapper is dried. The finished
I In-4+,1w are deposited in linnehes of 25 by the ndles elinia. and, after being banded with a narrow strip of paper, are ready for shipment. By this process from 5000 to 6000 envelopes per hour can be made by a single machine.
During the closing years of the nineteenth cen tury there was a remarkable development of labor saving devices for office use. Among these inven tions are various improvements on the ordinary gummed envelope. In one form a wire is so at tached to the inner edge of the envelope that by pulling it at either end the envelope is neatly torn open without the use of a knife. Then there are various devices for fastening together enve lopes which are intended for inclosing second-class or unsealed mail or simply for filing purposes. Among these patented devices are numerous clasp fasteners, like those in which a thin nar row strip of flexible metal is attached to the body of the envelope and, for fastening, passes through an eyelet in the flap and is bent over; or those in which a cord attached to one eyelet is wound around a second eyelet. An envelope for mailing third-class matter, like circular letters, so as to have the appearance of first-class mail, is made by leaving ungmnmed a portion of the flaps, so the contents may he inspected. Expansive enve lopes for filing purposes arc made with fluted ends that fold over each other, so the envelope occupies hut little space until it becomes well filled.