US58748A - Improvement in geographical maps - Google Patents

Description

UNITED STATES PATENT E. A. APGAR AND A. C. 'APGAIL OF PHlLADELPHlA, PENNSYLVANIA.

IMPROVEMENT IN GEOGRAPHICAL MAPS.

Specification formingpart of Letters Patent No. fd, dated October 16, 1866.

To all 'whom it may concern:

Be it known that we, E. A. APGAR and A. C. APGAR, ot' Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented a new and useful symbolic language for expressing the size of cities and the heights of hills, mountains, and plateaus,.and also an inproved Method of Constructing Geographical and other Maps 5 and we do hereby declare the same is fully described and represented in the following specilications and the accompanying drawings.

The nature of our invention consists in the use of such triangulations and other geometrical figures t'or helps in inap-drawing', in which some one line in each case is selected and used for determining the lengths of other lines about the tigure.

rlhe importance of our discovery and invention consists in determining what line about the tig-ure to be constructed will best serve the purpose ot' a measuring-unit. In order to serve such a purpose, it must be a convenient measure or multiple oi' other lines whose lengths are to be determined by it. Ve claim vto have discovered for each ot' our geometrical iigures such a convenient measuring-unit, and to have made use of a new and highlyimportant method ot using this measuringunit for completing the figure.

The nature of our invention consists in a simple, comprehensive, and easily retained symbolic language and mode of constructing maps for the use of schools, whereby the pupil will be enabled, by a little practice, to draw and construct maps ot' States, continents, Ste., without the aid ot' a copy, and to remember the population of. cities, the height ot' hills, mountain-peaks, and plateaus. Nor will the pupil require the knowledge necessary for the ordinar r system ot construction. Our method is especially suited to the youthful capacity, but can be used with protit by the older and more advanced pupils.

In the accompanying drawings, which form part of this specification, Figure l represents the triangulation of the continent in accordance with our invention. Fig. 5, a table representing' the symbolic characters used.

rlhe following is a further explanation ot" our invention. In constructingthe triangulation of North America, the line A B is taken as the base ormeasuring-unit by which the lengths ot'other lines are determined. This rst or base line is biseeted at O, and the line C D is drawn at right angles to and one-haltl as long as A B. The points A and D, and D and B are next connected, and then the line (j D is extended to the left, making the whole line D E equal in length to A D or D B. The points A and E and E and B are connected with straight lines, and the are E B, drawn with D as center. A E is bisected at F, and upon A F is constructed the equilateral triangle A FG.

A skeleton map is thus produced which determines the position of the most important points upon the coastline, and also the general contour ofthe continent. The lines composing this geometrical expression of the continent are next bisected, trisected, or quadrisected, as the ease demands, for the purpose of determining the position of other important points about or within the continent. This geometrical expression of the continent is easily constructed, the relation between it and the continent readily remembered, and upon it the map may accurately be drawn. rlhere is no use made of mathematical instruments and no reference to degrees or angles other than right angles. Its use enables the pupil to draw from memory.

Triangulations similarly constructed are prepared for aids in drawing other continents, sections ot' continents, islands, die.

From the above it will be seen that we have invented a system ot' oft-hand map-drawing, (the necessity of which professional experience has taught us, in preference to the abstruse and complicated methods in present use,) whereby a knowledge ot' geography, through a plain and easy system ot' language and construction, may be acquired by the younger pupils without waiting for acquaintance with the higher branches or use ot' mathematical instruments; and thus it places geography side by side with the reading lessons, tor which object our invention, we trust, has reached the desideratum.

XVe therefore distinctly claim as original with us and desire to secure by Letters Patentl. The use for inap-drawing of such geometrieal figures as are constructed by taking in each case some one line as a measuring unit, by means of which the lengths of other lines about the ligure are determined. We do not claim the use of those figures which are constructed by the measurement of angles.

2. The trisecting and bisecting of certain lines about our geometrical figures for the purpose of determining the positions of certain prominent points along the coast lines ot the continents.

3. That symbolic language for maps in which dots and lines, arranged substantially as described, are used to represent certain .numbers, Whether of population of cities or the height of isolated hills, mountain-peaks, or plateaus in feet or miles or other units ,of measurement.l

E. A. APGAR. A. C. APGAR.

Witnesses J. B. GOWPERTHWMT, Guns. Davis.

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