US207111A - Improvement in blackboards - Google Patents

Description

E. G. DURANT. Blackboard.

N0.207 ,11'l. f Paten't edAug.2 0,1878.'

N'PETERS. PHOTO-LITHOGRAPHER. WASHINGTON, D. C.

UNITED STATES PATENT OFFICE.

EDWARD Gr. DURANT, OF RAOINE, WISCONSIN.

IMPROVEMENT IN BLACKBOARDS.

Specification forming part of Letters Patent No. 207,111, dated August 20, 1878; application filed January 3, 1878.

To all whom it may concern:

Be it known that I, EDWARD G. DURANT, of Racine, in the county of Racine and State of Wisconsin, have invented certain Improvemen ts in Blackboards, of which the following is a specification:

This invention relates to a material intended to be sold in the market for application and use for blackboard purposes; the same consist ing of thin layers or laminae of wood cemented together, and provided with a coating or surfacing of paint or fine silicious matter adapted to receive chalk-marks.

Many attempts have hitherto been made to produce a blackboard material which would be free from objection, and which would be suitable to put upon the market as an article of merchandise to be applied by the different consumers to the various uses and places required, and with this end in View different articles have been employed, among others paper and cloth properly surfaced; but, owing to various objections developed by use, they have all failed to meet the demands of the case.

The principal requirements of a blackboard are, that it shall be unaffected by moisture; that it shall not under any circumstances shrink, swell, or warp; that it shall not be liable to check or crack under the continual exposure to the heat of the room; that it shall be light and easy to handle; that it shall occupy but little space; that it shall be adapted for application in a simple and permanent manner to the walls of the building, and that it shall be perfectly stiff and rigid under all circumstances. Each and all of these requirements are answered by my board, but not by any other hitherto produced. Beinglight, strong,

and stiff, easy to handle, extremely cheap to construct and transport, my board will be found superior to all others, and to supply a The drawing represents a perspective View of a sheet of my material.

A represents the sheet composed of the wood layers a b c, the number of which may be increased to any desired extent. The layers are arranged with their grain running in difl'erent directions, and are cemented or glued firmly together, intermediate layers of fibrous material being added, if desired, to give the blackboard greater strength.

The front layer, or, if desired, the others also, are treated with oil, varnish, or any other suitable material to render them impervious to moisture, and the front or front and back surfaces are treated with slate paint, or any of the various well-known silicious or slating solutions used for blackboards.

Having thus described my invention, what I claim is A blackboard consisting of two or more thin layers of wood united crosswise of the grain, cemented together, rendered impervious to water, and coated with a silicate or other slating solution, substantially as and for the purpose described.

EDWARD G. DURANT.

Witnesses L. S. PORTER, FINLEY 1-1. McADoRR.

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