46 Tlic AiinrtcKn ( rii)]()t//sf. J;iiiii.-iiy, !««•'' 
course, for sucli causes that tuiy selieuu' should he nuido applicable. 
If there ho cxceptious or irre<iuhiritu's. as in tlic case of "iinor- 
s;anizc(l ' counties, wliich arc apt to l)c tcui[)()rarily larji'c. like the 
euornioiisly laruc counties of noitherii Minnesota, there arc va- 
rious ways in which those maps eau still be brought within the 
requirements of the '-review. ' 
1. They miuht be reduced to the minimum scale. i)articularly 
if their gcolouv is unimportant, or largely unknown, like some 
of the (b'ift covered countii's of western Xel)raska or northwestern 
Minnesota. 
2. Tn extreme cases when im[)ortanl geology in an •■unorgan- 
ized" county must Ijc delineated, oi in an organized county too 
large for handling in (piarto style as expressed altove. it would 
be best to divide such area into two or more maps, numbered con- 
secutivclv and so i)laced in the volume as to be of convenient ri'f- 
erence. 
:>. In the case of very small countii-s. it is invarialtly the case 
that such are thickly inhabited, and theu the greater usefulness 
and popularity of the .maps would justify a larger scale than for 
the others. For instance. Ramsey county, the smallest in .Minne- 
sota,* embraces St. Paul, the capital of the state. There appears 
to be no unduly large scale in the plate map Avhich shows its geol- 
ogy in the report of the Minnesota survey. (Final report. Vol. 
II. plate 43.) 
4. If there be. in any state, several such counties, and it is 
thought best not to expand them over a ([uarto page in giving 
their geology, it would be a sim()le problem to so reduce them 
that two could be expressed on a single page, or at least on a 
folded sheet. 
The devices that may be resorted to to embrace all the mapped 
areas within the sizes re(piired by the '-review' are luimerous, 
and eA'erv geologist must employ ihem according to his i)articnlar 
conditions. It is not ditficult to bring objections against any sys- 
tem of mapping. l)ut it has appeared to us that those state maps 
that have adopted the county as the unit have avoided a larger 
uumbcr of complaints than the others. 
We would add in conclusion, that we qiu'stion the propriet}', 
*Prof. Winslow gives the extremes of county areas in ^Minnesota as 
162 square miles and 5,800 square miles. They are actually 187.15 
square miles (ivamsey) and 0,611.75 square miles (8t. Louis). Final 
report, ^'ol. i. p. U4. 
