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Publication numberUS123456 A
Publication typeGrant
Publication dateFeb 6, 1872
Publication numberUS 123456 A, US 123456A, US-A-123456, US123456 A, US123456A
InventorsMabcellus F. Cowdbey
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Improvement in blackboards
US 123456 A
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Description  (OCR text may contain errors)

M. F. COWDERY.

Blackboard.

No.123,456. A PatentedFeb.,1a72.

MAROELLUS F. OOWDERY, OF SANDUSKY, OHIO.

IMPROVEMENT IN BLACKBOARDS. i

Specification forming part of Letters Patent No. 123,456, dated February 6, 1872.

consists in treating to a thorough coating of boiled oil the paper fabric which forms the body of the blackboard, to render the same impervious to moisture, and thereby prevent its warping or becoming harsh, and consequently cracking and becoming Worthless.

After the paper has been thus prepared I linish it on both sides With any of the ordinary blackboard compositions.

In the drawing, Figure l represents a blackboard, both sides of which are finished similarly; also, a section along the line X Y, in Whichb is the fabric, which has been treated with boiled oil, and c a are the coatings of blackboard compositions.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The blackboard, When the paper fabric of which it is composed is previously treated with boiled oil, as and for the purposes herein described.

Witnesses: M. F. COWDERY.

M. E. McLoUTH, O. C. MGLOUTH.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2452235 *Mar 2, 1946Oct 26, 1948Milprint IncBlackboard
EP1441838A1 *Oct 17, 2002Aug 4, 2004Criticare Systems, Inc.Gas/liquid separator including a liquid trap filter
Classifications
International ClassificationF24F1/00, G02B1/00
Cooperative ClassificationC40B10/00, F24F6/00, F24F2001/007, G02B1/00
European ClassificationG02B1/00