US155894A

US155894A - Improvement in sun-dials

Info

Publication number: US155894A
Authority: US
Publication date: 1874-10-13
Anticipated expiration: 1891-10-13

Description

D. B. SCOFIELD.

Sun-Dials.

wnuzssts:

ATTORNEYS.

UNITED STATES PATENT Orr'ron.

DAVID B. SOOFIELD, OF AUBURN, OREGON.

IMPROVEMENT IN SUN-DIALS.

Specification forming part of Letters Patent No. 155,894, dated October 13, 1874; application filed March 28, 1874.

To all whom it may concern:

Be it known that I, DAVID B. SooFrELD, of Auburn, in the county of Baker and State of Oregon, have invented a new and Improved Sun-Dial, of which the following is a specifi cation:

1n the accompanying drawing, Figures 1 and 2, respectively, represent end and front elevations of my improved sun-dial; and Figs. 3 and 4 side and front elevations of a modification of the same.

Similar letters of reference indicate corresponding parts.

The object of this invention is to produce an improved suirdial, which may be used and adjusted to any latitude, and then permanently attached for indicating the time whenever the sun shines.

The invention will first be fully described, and then pointed out in the claim.

In the drawing, .A represents the body of the sun-dial in the shape of a quadrantal part of a cylinder, the front and rear sides of which are formed by the radial planes meeting under a right angle at the apex of the same. The end sides are quadrants of a circle, and are pivoted to the standards of the base B, or directly to the same, as preferred, so that the body A of the dial may be swung on the base to either side. The front and rear sides are recessed in the shape of segments between the ends, as shown in Fig. 2, or from the middle part toward the ends, as shown in Fig. 4. The front side is slightly beveled, and gradu ated along the arc of the circle formed by the recess in such a manner that the lowermost point is the noon-point, While the morning hours are placed along the are extending to the right, the evening hours along the are extending to the left, therefrom. The graduated arcs may be extended beyond the apex of body A by detachable pieces A, which are inserted into recesses of the same, as shown in Fig. 2; or the arc may be permanently formed by extending the front side beyond the apex of body, as shown in Fig. 4 or still another modification may be used by attaching the graduated arcs for the hours before and after six in the morning and evening firmly to the rear side, at the central part thereof, as in Fig. 2, the time being indicated thereon by the shadows of the apex of the ends. The indicator 0 is placed centrally to body A and vertically to the plane of the front side,

so that its edge forms an extension of the rear plane, as in Fig. 2; or two indicators, 0, may be applied as continuations of the quadrantal ends, to be used in connection with the separate-arc gradations for morning and evening, as shown in Fig. 4, they being also vertical to the plane of the same. The end sides of body A are graduated with verticals and horizontals numbered with different degrees of latitude, so that the base B may be set to the latitude of a certain place by bringing the corresponding horizontal line to a level; or setting a central index, a, of base or standard to the correspondingly-numbered vertical line, as indicated in Figs. 2, 3, and 4.

The dial may be constructed of any suitable material of wood, metal, and stone, and finished accordingly, the base part being screwed or otherwise firmly attached to the point where the dial is to be used.

The dial is used in the following manner: The base is applied to its level support, and the body set with the indicator so placed that the upper edges of the same are parallel to the axis of the earth, and point exactly to the true north point near the north star. The plane of the circle is thereby parallel to the equator. The shadow of theindicator upon the graduated arcs gives the time by the marks and figures thereon, fifteen degrees being made for one hour. The body is also ad justed into the required latitude, as described. Any variations of time on the dial from the time when the sun is on the meridian is due to the refraction of the suns rays, so that the mean time of the place may be computed by these refractions and tables of equation of time.

Thedial may be easily shipped, taken oil", and readjusted, and forms thereby a convenient and accurate instrument for giving the measuring time of any place.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- An adjustable, pivoted, graduated sun-dial, having the upper edges of the meridional gnomon straight, and a northern face provided with beveled edges, and graduated to denote the time upon the face, as shown and described, for the purpose set forth.

Witnesses: DAVID B. SGOFIELD.

I. D. MCFARLAND, J AMIES H. SHINN.