US188083A - Improvement in slates - Google Patents

Description

Patented March 6,1877.

`SLATE.

www3

Lawn... MERQ .XN

m Q 888ML ET .TT

G. S. VELEZ.

INVENTUB TTUBMEYS.

N liflZfIIIfl N. PETER;FHOTOLITHOGRAPHEE, WASHNGTON. D C.

UNITED STATES PATENT GEErcE5 GEORGE S. VELEZ, OF NEW YORK, N. Y.

IMPROVEMENT IN SLATES.

Specification forming part of Letters Patent No. 188,083, dated March 6, 1877; application led January 29, 1877.

To all whom it may concern:

Be it known that I, GEORGE S. VELEZ, ot' the city, county, and State of New York, have invented a new and Improved Multiplication-Slate, of which the following is a specification:

In the accompanying drawing, Figure l represents a top view, and Fig. 2 a vertical transverse section on line m x, Fig. l, of my improved multiplication-slate.

Similar letters of reference indicate corresponding parts.

The object of this invention is to provide an improved device for facilitating and expediting the multiplication of larger and smaller numbers by the assistance of mechanical means; and the invention consists of a slate with a sliding slate-rule, guided in a slot or recess of the slate, and worked in connection with the graduated or subdivided edges ofthe adjoining slate-sections.

In the drawing, A represents a slate, with a longitudinal recess, a, in which the sliding rule B is guided, by means of suitable rails b or otherwise.

The sliding rule B is worked by a springbutton, C, in connection with a pinion-andrack mechanism, D, or by equivalent mechanism, so that each depression of the button O feeds the slide-rule forward the length of one tooth.

By releasing the check-pawl D', or other check device, the rule B can be moved or sprung back into its original position, so as to close or till the opening or slot ct of the slate.

rEhe sliding rule B is provided with a lling of slate or other material, on which may be written with a slate or other pencil, the slate-filling being divided by cross-lines into subdivisions or sections of such size that a gure may be readily and conveniently written into each subdivision.

The adjoining sections of the slate A are marked or graduated in the same manner, so that the dividing-lines of the sliding slate-rule register with those of the slate-section.

The guide-rail and rack may be similarly marked, so as to facilitate the registering of the different dividing-lines, and bring thereby the figures placed into the subdivisions of the sliding rule and adjoining slate-sections into corresponding columns.

The multiplication-slate is used as follows, the different operations being accomplished by mental process, without being specially written down: The figures of the multiplicand are placedinto the divisions ofthe upper section of the slate, and those ot' the multiplier in the divisions or columns of the slate-rule, but in reversed order, the units of the multiplier being placed below the unit figure of the multiplicand, and the tens, hundreds, &c., to the right of the unit ligure. Ilie units are then multiplied, and the unit ofthe resulting number placed into the column of the lower adjoining slate-section. The button is now depressed, and the slate-rule moved forward so as to bring the units and tens of the multiplier below the tens and units ofthe multiplicand, after which the units and tens are multiplied and added to the ligure obtained before by the multiplication of the units. The unit gure of the number so obtained is the ten figure, and is placed in the second column adjoining the unit ligure of the result. The slate-rule is then moved again, and the same operation continued until all the gures of the multiplier have passed below the figures of the multiplicaud, as shown clearly in Fig. 1 by the detailed multiplications accomplished mentally at each position ot' the slate-rule, and which exemplify instantly the method of using the slate.

The mental process necessary is easily learned and quickly accomplished, so that the result may be written off directly into the columns of the lower slate-section, facilitating especially the multiplication of larger numbers, so as to be useful for schools, business-houses, stores, Src., as a considerable saving of time is obtained, and the number of mistakes incidental to the present method considerably decreased.

Having thus described my invention, I

I claim as new and desire to secure by Letters Patent- 1. A multiplication .-slate composed of a. ing slate-rule, and suitable mechanism for slotted slate, with graduated or subdivided moving the 'samel forwardand back, substanadjoining sections, and of an intermittently- 1 tially as set forth. sliding and subdivided slate-rule, substantially as and for the purpose set forth.

2. The combination of a slotted or recessed slate, having suitable guide-rails, with a slid- GEO. S. VELEZ. Witnesses:

C. SEDGWIGK,

ALEX. F. ROBERTS.

Images