240 
A Pocket Mapplny lastrument. — Line. 
ment I have to describe, which in default of a better word we 
might call a "geograph," has proved a handy consolidation of 
some of these instruments. 
It consists of a frame (see figure *) like a picture frame with 
a removable back 
JM7. 
held in place by the 
spring shown in 
dotted line, as in a 
"^ photographic print- 
ing frame. This 
frame is of any suit- 
able size. The one 
I have been using is 
54^x7 inches, outside 
measurement, and 
will cover a couple 
of land sections with 
a broad margin, at a 
scale of 2 inches to 
one mile. A larger one would be in many ways more con- 
venient but this just slips into my pocket. At the lower left 
hand corner is an oblong compass box (A) with width enough 
to allow for a magnetic variation of several degrees and a stop 
(B) to lift the needle up when not in use. 
The right hand side has a semi-circular groove, and from 
the back of the frame curve forward two strips of elastic brass, 
(C) and (D), D forming a trifle over a quadrant, C very nearly 
a semi-circle. The pencil is thrust through C and then 
pressed into D. A small rubber band is twisted three or four 
times around the pencil, which increases of course the pres- 
sure needful to press it into place, and prevents its falling out 
or rattling. I have never lost a pencil from the holder. 
Above the compass on the left hand side is a sun-dial for 
determining true north, when the time o'day is known or vice 
versa, — for regions of local attraction indispensable. From a 
small hole in the frame at G an elastic cord runs through a 
hole or notch near the top of a movable arm E which is 
hinged at F, and thence over the top of the frame in a slight 
groove to the back where it is fastened. When the arm E is 
The figure is drawn in crystallographic projection with tlie thick- 
ness and breadth of frame increased out of proportion to show the 
construction better. 
