Collection:
Juneau—Douglas City Museum
Object ID:
2007.22.141A—P
Accession#:
2007.22
Credit Line:
Transferred from the U.S. Bureau of Land Management.
Object Name:
Machine, Drafting
Title:
Portable Perspective Sketcher
Year Range from:
1940
Year Range to:
1980
Description:
Portable Perspective Sketcher.
Gray—blue wooden case in the shape of a triangle. Top cover of the case has "DELICATE INSTRUMENT' stenciled on in black letters and the initials "U.S.B.M." written on, probably in black marker. Inside the case is instrument.
A — Carrying case
B — Altitude column with attached arm assembly. Column is four—sided with a heavy duty clamp on one end. Two black metal moveable collars fit over the column. The top column is for the arm assembly, which consists of two parallel brass rods that are jointed at the center by two interlocking cogs.
C — Stylus assembly. Verticle brass rod with base made up of four black metal feet. Between the feet underneath the assembly is the long narrow, pointed stylus. The top of the assembly attaches to the end of the arm assembly (B).
D — Short stylus extension — Brass pipe with a black metal collar and brass knob at one end. Overall length 8.0 inch.
E — Long stylus extension — Brass pipe with a black metal collar and brass knob at one end. Overall length 16.0 inch.
F — Picture panel assembly — Arched steel plate with a four—sided arm that attaches to the lower collar on the altitude column.
G — Pencil extension. Two brass legs pinned to a steel bracket. Steel bracket has two brass thumb screws which are used to attach it to the arm assembly when needed.
H — Measuring stick — Black plastic with a 1:5000 scale in white writing.
I — Right triangle — Black plastic with while stenciling: "PORTABLE PERSPECTIVE SKETCHER/U.S. NAVY DEVICE NO.16—C—12/THWING—ALBERT INSTRUMENT COMPANY/PHILADELPHIA, U.S.A."
J — Steel stylus needle.
K — Stylus needle with attached brass thumb screw.
L — Brass thumbscrew.
M — Brass thumbscrew.
N — Lead push—out rod. Wire rod with a loop at one end, overall length 3.5 inch.
O — Pencil clutch tube, brass, 2.5 inch long.
P — Paper.
Q — Eagle brand drawing leads box — brown box with white writing and a blue icon showing an eagle clutching a pencil. Box says: "HALF DOZEN / NO. 2375 / EAGLE / TURQUOISE / DRAWING / LEADS / 2H / EAGLE PENCIL COMPANY" on the front of the box. Inside is a wooden holder with three pieces of pencil lead.
Notes:
Designed during WWII by the Navy and used to produce in perspective the elevations represented by the contour lines on topographic maps. This sketcher was war surplus and eventually transferred to the Bureau of Mines. Manufactured circa 1940s.

See the document file for object description and instructional images. Operating Manual and Parts Catalog is in the document file.
Search Terms:
Drafting
Mine
Mining
JMIC
Map
Navy
Military
Subjects:
Map making
Click to Enlarge
Perspective SketcherPerspective Sketcher
Perspective sketcher casePerspective sketcher case
Diagram of Perspective SketcheDiagram of Perspective Sketche