, 1879-06-21

into AaAe HtnalpeBs tnen poured their Breal
volumes of water through the present val
loyn of Rod River and tho Minnesota Rivsr.
In thai day tho present Mtsassippi nivs.
abovo tho junction with tho hfiunesota
Isivor wna branch OF the main
stroam, and what Mo now known
na tho N[innesota, He'd River, Lake
Winnipeg, Saskatchewan, and Assiniboino
Rivera vera tho original Mississippi River,
whose sources were afar of IN the Rocky
Mountains. Tho present basin Of The Red
River WAS then = want widespread 1ake,
Which has by some natural change been
drained and ita supply Of water direoted
1nlo Lake Winnipeg and thence into Hul-
sons Bay, leaving the once grand and rapid
Minnesota amsll tributary only to the great
Mississippi River, Of which II was originally
an important and integral part.
In 1866 Congress n,ado An appropriation
for survey Of the Minnoaota nivor, aud
Maj. WARREN. Of Tho Engineer Corps, was
assigned to tho duty. Illness and other
causos permitted him to mako only partial
report i'll 1868 but in 1874 ho complete his
report, In which he included a most In.
tcrosting discussion of this whole subject.
l1o reaching tho conclusions which VIC hayo
briefly statod, that tie whole volume Of
water now drained into Lnko Winnipeg,
and into Lake Manitoba, and into tho Red
River of tho North, orco flowed south
through the basinH Of the llod River and OF
tho Minnesota River to wl,nt is nov tho
Mississippi River, md thence to the Gulf Of
Me1'co. In The report blaj. WAnnzN says:
Having In The preceding discussion shown that
Lakc Winnipeg formerly was continuous 10 tho
Minnesota Valley, Wkh IN outlet olonr the yalley
to tho NFsaisslpp we must at onco Infer that tho
existing outlet By Nelson's River 10 tho Hudton's
Bay diu not then exist. Ne have no example In
Nature Of any great lake having two out1es at the
same time IN operation II IL not readily conceir.
abba how two such could ever hsye formed. Our
general idea IL that lake 10 depression Of tl,e
earth's surface, which becomes partly or entirely
h!lct Nith wAer. ana In tho attat casa II owz out
At the 10" crt point In the margin or rim of tho
basin, Thereafter This outlet prevents farther r!so
Of tho watsr by draining It OF from the lake
10 tast ~ 1t enters, and thus 1t cannot
overflow At some other point, Now, inns.
much as tho closing Of The Nclson'4 niycs
outlet ut the present time would cause
Lake Winnipeg to rlts till 1t would run out at The
Minnesota Valley. II at hrst seemed plausible 10
suppose that II tho g!acinl period tempered OF
gtadualY into tho present geological epoch, tbsro
might haso been long timo when tho glaciers had i
sttll sufficient extension soulhward to close th!a
outlet to ltulson'a bay. Then on tho further
recession OF the glaciers norshward, tile present
outlet would be presented and tho fkke drained OF,
Although somathing like this may have occurred,
II ~, SO fdf hs now know. an unsupported hYpDth.
esia. nnd barren OF hAY ftut. It will not aid us In
explaining any phenomenon presented By ptler
lase oasina aud water courass Of North Amerlca,
nor cnablo uF to predict rhat proboble results we
shalt Ind In OTHER regonAt and thus late]lieent1y
direct further investigations.
The hypothesis which have found 10 account
satisfactorily for ths change Of outlet from what
It formerly "aa. down tho Minnesota aud 1LIss!E.
sPpi to the Gulf of Mexico, to what 1t now H. by
way OF Nelson's or Sea River 10 Hudaon's BAY,
"a 10 rcgatl It a. result Of gradual change Of
inclination OF tho surface of tho low interior poe.
tion Of tho continent caused bY slow elevation os
tue southern part and subsistence Of tho northern
part. Tbs otevating forco appearn 10 cnme from,
that DART OF tho carth'a surface occupcd By tho
taclhc Ocean. and tho line Of tho greatest epre1.
s!on ~ somewhere near Greenland, or bctween 1t |
and thc continent. At sono. intermediate region |
mere should bs no change In The eevatlon but the
change OF slope would be, going on Ia tho same |
direction throughout. With 4shs4e assumed con. |
ations We eau mentally 90 back In tlmo 10 period |
when all Of tho Winnipeg Lake gasiu-tho 1ako I
being shhllow-wAa at II h!shor.lorel than tho low.
Dat axsal line OF tue continental basin south Of it.
u which u would form a part, in that casa no |
axe would exist In tho hasin. It being completely
Trained soutlwar1. At'such tluse Tho surface Of
|lndson'H Lay and Of tho Arctic Ocean would be
much fcsa than now. and thare would 10 d much |
sreateF extension noFthwnrt OF the wAtess OF tue
3ulf Of Mexico. With aucl, conditions the cold 1T
tho North would be intcnatdcd and extend farther
south than now, while the northern extension Of |
Ao 0a3f would carry Tho With, mot4s winds Of the