Man (\ lid tit' (ihicHil Prriod. — Sal/Klmr;/. J 7 
dam at ('inciiin;il i. We li;nl >ii|p|i<>sc(| tins iiolioii iicjirly (>l)S()lctP. 
It has h('(Mi (•(inclusively show II. sii it scciii> lo iii.-iiiy K<'<'l<>K''*fi^- tl)at 
if tlie livpotlx^tical icc-diiiii and its hike cxistpd at ( inciniiMl i. it (•onhi 
not liav(^ Ioi-mkhI tlic ten-aces attributed to it. since I lies are not lake 
terraces. It has been liirtiier shown that the silts ascrii)ed to the lake 
along th(" Ohio above the site of the alleged ice-dam. are continuous 
V\ itli like silts which occupy corre>| ion (ling |iosit ion- lie low the allegrd 
ice-dam. and thererore were not (ieiiosir(Ml in a lake made liy it. If 
therefore, the ('incinnari ice-dam iiypothois >ur\ivi\its su|i|ioi-ters 
must needs find some new basis Cor il to rest ii|ioii.ror a (lam iMU>t 
liave a I'oundittion lieiieatli it. 
I'rof. Wright seems to us often uiiju>t lo ol her A nierican geologists. 
Some of these are ignored. e\ en w hen l lieir w dik ha- a direct and im- 
portant bearing upon tlie sul)j(^ct undei- discussion, in >ome cases 
tliey are inis(proted or [niisinterjireted. or their work put in a false 
relationship. This is doul)tless a no more serious charge than care- 
lessness. Hut in some cases the car(dessii(^ss goes so fai' as to be seri- 
i)iis. For eXMNipie : I 'res. ( hamlierlin is (| noted as ■■maintaining" that 
the ice-epoclis were "seiia rated by :i jieriod in which the ice Ii;id 
wholly disappeared from the glaciated area l<i the noil li." i ji. l(i!)i. 
('liand)erlin's printed statement on this point, in discussing t he retreat 
of tlie ice after the first glacial e|K)eli. is this: "'How far to the north 
this retreat carried the nnirgin has not \('t been ascertained, but the 
growing tendency of the gathering e\ id en ce is to I h row it fart lur and 
farther back, and it is l lionght to be (|uite safe ro beiie\ c that it w itli- 
drew entirely fi-om our territory, if not fidin the (anadian liigliland" 
(vol. 1. (ieol. of Wis., p. :.'7I 1. The same author is again mi>(|Uote(l in 
connection w ith I'rof. Comstock. These gentlemen have suggested 
(hat changes of latitude in past t inie- may perhaps have been a cause 
of glacial clin)ate in those regions which now |)ossess a genial <'limate. 
hupiKirting the suggestion by astronomical observations on actual 
variations in latitude in recent times. Tliey liaxc pointed out the 
importance of careful obsersation on t lii> point in the fill u re. and the 
need of mo.-t thorough iii\ est igal ion of liie whole miIiJ-cI of pole 
movement>. ( )ne or both of them ha\e speculated coneeining the 
climatic result- which would lia\c alleiided wandering- of ihc pole 
extensive eiiougli lo bring il (low n to < i reen la nd. for this 1 hey are 
<| noted (p. '.M\~ \ as ■■niaiiil ainiiig" that the norl 1: pole '"w a- -omew here 
in the region of cent ral< ireenland "■ -■ "•'" at the 1 ime of i he gla- 
cial, period. 
.\gain. in connecl ion w ith the r( ferences to the diiflles- area. (p. 
103) the credit for its explanation, so far as it i> explained, i- attri- 
buted to ("hamlx^rlin. i'.ut Wiiich(dl and Irving liad iioth iirg(Ml some 
points in the accepted explanation before its fiilh r slalemeiit by 
(')niniberlin. and to each belongs some pari of the credil. The refer- 
eiic(^ to the work of Mr. beverett I p. KM) seems to imply that il is 
inconsistent u it h l he vsork of ( hamberliii. w hile in point of fad this 
work was inaugurated and directed li\ the latter, and some of the 
