74 THE WOODSMAN’S HANDBOOK. 
acres largely compensate each other. It is only when the chain- 
ing is used for a topographic map as well as an estimate that accu- 
rate chaining on the horizontal is necessary. 
It often happens when a line of strip surveys is run across a given 
area that the last strip is less than 10 chains in length. Strictly, 
this should be regarded asa fraction ofanacre. Thus, for example, 
if the last strip is 44 chains in length, it comprises 0.45 of an acre. 
When the results of the measurements on this short strip are used, 
and it is necessary to give figures of stand per acre, they must be 
divided by 0.45. In practice, however, where the forest is uni- 
form, the whole acre is completed, either by continuing over the 
line or by turning and finishing inside the line in another direc- 
tion, in order to facilitate computation and to avoid fractional 
acres whose results must be converted into terms of whole acres. 
PREPARATION OF A FOREST MAP. 
The preparation of a forest map oiten is combined with the esti- 
mate. In most cases a contour map is not planned, but rather a 
map which will show simply the distribution of the timber, the 
forest types, the location of the roads, streams, and main ridges. 
Such a map is prepared in the following way: When a strip inter- 
sects a road or stream the tallyman notes the point of intersection 
and also the direction of the road or stream, so that it can after- 
wards be located on the map. Ii a road or stream crosses several 
strips the points of intersection are connected on the map and the 
exact location thus indicated. When a stream or road is crossed, 
the tallyman takes any steps necessary to record its character and 
width. The description of each acre includes the general direc- 
tion of the slope, and if there is a marked change in the degree of 
slope in the middle of the acre, that fact and the point of the 
change are noted. The location of ridges may thus be determined 
and sketched on a map from the description of each acre. 
It is possible, also, to make a map of the forest types, because 
the description of each acre includes a statement of the type. Ii 
an acre crosses from one type into another, this fact is explained 
on the tally sheet and the point of change is indicated, so that the 
outlines of the different types may be sketched on the map in the 
same way as the roads and streams. 
