Winslow —The Mapping of Missouri. 97 
tions of coal beds and topographic features of special impor- 
tance. Between these lines, altitudes have been determined 
by aneriod barometer measurements along the lines of meander 
surveys. Such meander work was performed with hand com- 
pass and paced distances following along roads, or along sec- 
tion or other land lines, and, in all cases, was checked by 
frequent intersections with such lines. In such surveys the 
_ topography was sketched, at the same time, directly into the 
note book and all observed geological occurrences were located 
in their proper topographic positions. These methods are 
accepted as adequate for the construction of a topographic 
map for purposes in view, on the scale and with contour 
interval used. More must not, however, be demanded of 
such maps, than these considerations warrant, though they will 
prove of value in the future for many other industrial and 
scientific uses than those for which they were especially con- 
structed. They portray with exactness the distribution of 
upland and lowland with reasonable faithfulness the relative 
elevations of the various hills. It is not maintained that the 
exact amount of grading necessary for the construction of a 
railway across the areas represented can be calculated from 
the study of these maps; yet, on the other hand the general 
question of the practicability of construction along any line 
can be determined at a glance. 
The plan of publication proposed for these sheets contem- 
plates that they shall be issued under paper covers, together 
with the accompanying section sheet, unfolded at the end of 
a folio report of a dozen or more pages of the same size as 
the map. A series of these sheet reports can be bound later 
under more substantial board covers. The areas selected for 
such detailed work, are those which are of prominent economic 
importance, or which are of great geologic and scientific in- 
terest. It is the intention to complete several such sheets 
each year, along with the other work of the survey of more 
general nature. The value of such detailed work to the State 
is second to none among the various products of the Survey’s 
operations and we feel little hesitation in predicting that this 
series of maps and accompanying sections and reports will 
prove of more substantial and enduring value than any other 
of the publications. 
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