48 The y\iru'l'tcatl (i< nhxjisf . Jjinimrv, IH'.tS- 
ical l):ise.' It stH-iiis to us tlml .Mr. (iniinctt will sr^rch in vaiu 
for any fsiich v'u'ws in our oditorial. We said (p. ill 0): • • Tiie 
Geological survey sliouid follow the mensuration survey — so far 
as its niappiui;- is concerned." We admit that we remarked that 
many i-nrni-t geoloiiieal majjs hav(> hccn const I'ucted without jji'e- 
vious toi)ourapliical ma|)i)ing. That was to show that the simple 
geological maps contemi)lated by the organic law of the survey, 
for tlie illustration of the 'iniiu'ral rcsoui-cesanil the classiticatioii 
of the lands'' could be constructed correctly without clabitrate 
topographical surveying. 
4. The letter of Mr. Gannett aims to impair our argumenta- 
tion on this sul)ject and our good sense, which miglit otherwise 
be brought to bear on it, l»y assuming that we are not '-practical 
geologists,"' and that therefori' wc are pardonalile in not knowing 
what [)ractical geologists need in the construction of geological 
maps. Tliat is a '-man of straw'' which is so frail that it can 
hardly stand alone. The writer of that editoiial has seen many 
years of practical geological work, and has constructed numerous 
geological maps, and he ought to be as comix'tent to speak ou 
the needs of geological mapping as any toi)ograi)lu'r. however 
expert in geodetic measurements. 
5. Again, here is Mr. (iannett's statement: •■ The writia- for- 
tifies his statement by the assertion that up to the time the United 
States Geological Survey commence*! systematic topographic sur- 
veys (1882) no geological survey had found it necessar}' to do 
topographic work.'' Now look on this, which is our actual state- 
ment: -'We know of no precedent for it: but so far as ex- 
ample goes its iurtuence would be o[)p()scd to it. The topograph- 
ical mapping done by the early territorial surveys was discon- 
tinued bv act of Congress, and no state sui'vey had at that time 
entered upon topographical mapping under a law oidering simply 
a geological survey.'' The ditference is so broad t hat any topog- 
raph(M- ought to be able to discover it. 
(;. •• His argument is that the higher the price the better the 
(piality. ^V<^ made no such argument. Itut it is a good [)rinciple 
that. ril< ris i>(i riliKx. the price is a good gauge for measuring the 
quality. 
7. Mr. (iannett imputes to us '-an attack ' upon what is 
" presumably a useful work,'' implying theniby that we are op- 
posed to the continuance of tiie topogra}>hical survey. We in^ 
