1838J 



FARMERS' REGISTER. 



171 



this case, a diversion of a much greater volume of 

 water, and to a more remote destination, will be per- 

 fectly practicable; and the power which holds the iij)- 

 per extremity of the canal, may at pleasure direct this 

 enormous Hood either to a northern or a southern part 

 of the ocean, two thousand miles apart. 



But the interest of these speculations extends still 

 farther, and to another subject. It is evident, from 

 the geological features of the country, that the great 

 northern lakes at some early time stood so inucli 

 higher tlian at present, that part at least of their 

 waters actually were discharged down the valley of 

 the Mississippi; and that the proposed new canal will 

 but renew a passage of water which nature had at 

 first provided. The great barrier of limestone which 

 forms the southern boundary of Lake Michigan was 

 less destructible than that which is still wearing away 

 under the action of the cataract of Niagara; and by 

 that slow but continued process the levels of the lakes 

 have been greatly lowered. — Ed. Far. Reg.] 



[Extract from the Journal of Science.] 



Before dismissing this very striking appearance 

 of the coast connected with the action of the lake, 

 I must be permitted to express the opinion, that a 

 careful examination of the country bordering on 

 the Kankakee and the Des Plaines valleys, will 

 afford evidence of the occasional overflow of the 

 lake at ancient periods, in those directions. It is 

 a well known tact, that the lip of the lake, near its 

 south-western extremity, is at one place so de- 

 pressed as to permit canoes to pass from the head 

 waters of the Chicago river across to that of the 

 Des Plaines. Nor would the circumstance cease 

 to be an alarming one to the salety of this portion 

 of country, except lor the tact that the border to 

 the lake is every where composed of a firm lime- 

 stone. If then the waters of the lake are still ca- 

 pable of interlocking with those of the Des 

 Plaines, it is clear that at a higher level of the 

 lake, considerable descents of water upon the low 

 country must have taken place. Traces of such 

 incursions appear to exist on the stage road from 

 Chicago to Ottawa, in the general direction of the 

 swells of land on the rolling prairie, and more par- 

 ticularly in the widih and deptli of the Des 

 Plaines valley, and the immense diluvial accumu- 

 lations it contains below Juliet. 



No internal improvement in the country will 

 surpass in commercial importance the canal which 

 is to unite the waters of Lake Michigan and Illi- 

 nois river, since it will complete the navigable 

 route from the Gulf ot St. Lawrence to the Gulf 

 of Mexico, and open a water communication, so 

 to speak, from the Rocky mountains to the Atlan- 

 tic coast. The cost of the undertaking in some 

 degree keeps pace with its importance; lor al- 

 though neither the line of its extent, nor the 

 amount of its lockage, is great, still the dilHculty 

 which grows out of obtainmg an adequate supply 

 of water lor the summit division of the route, ren- 

 ders h the most expensive work of the kind ever 

 projected. It is indeed a fortunate circumstance 

 as affecting the certainty of its completion, that 

 the means for defi'aying its construction are alrea- 

 dy in the possession of the state, the general 

 government having given the alternateseclions of 

 land for five miles on each side of the canal to the 



state of Illinois, to be appropriated to this impor- 

 tant undertaking. 



Refbrc sjieaking of the geological features of the 

 country over which the canal jjasses, a brief 

 sketch of the route it takes, and the nature of the 

 ililliculties it has to encounter, will be given, inas- 

 much as such a notice will serve in some degree 

 lo explain the topographical features of the region. 



The canal passes up the south branch of the 

 Chicago river a distance of four miles, thence over 

 the level prairie in a direct line eight miles, to the 

 valley of the Des Plaines river, down the valley 

 of this stream, past the mouth of the Kankakee, 

 to the banks of the Illinois, whose border it pur- 

 sues for a distance of fourteen miles below Otta- 

 wa, where it enters the river. Its length is one 

 hundred and two miles; and it is constructed with 

 a breadth of sixty fi?et at the water surface, and a 

 depth of six feet. The lockage is all downwards, 

 and amounts to one hundred and forty-two feet. 



Eefore adopting the present route, an attempt 

 was made to obtain a supply of water for the 

 summit division, from the Des Plaines, the Calu- 

 met, and the Fox rivers; but on running a level 

 liom the Des Plaines, nearly opposite the mouth 

 of Portage lake, to the Fox river at Elgin, (thirty- 

 five miles south of the state line,) where the sur- 

 face of the stream is one hundred and fifteen feet 

 above Lake Michigan, it was found, that the in- 

 tervening ridge had an elevation of fifty or sixty 

 ftjet, the cutting down of which would be too ex- 

 pensive to justify the expedient. The commis- 

 sioners were accordingly led to adopt the magnifi- 

 cent plan of making Michigan the feeder to the 

 canal. The first level thereby becomes thirty-four 

 nfiles in length, with an average depth of cutting 

 of eighteen feet, which is principally in solid rock. 

 The depth of six feet of water has been decided 

 on, in order to secure to the canal a constant depth 

 of four feet during the fluctuations of tide in the 

 lake, occasioned by high winds. A declivity is_ 

 given to the bottom of the canal, of one-tenth of 

 a foot per mile. There are two locks situated at 

 the end of this level, having a lift of eighteen feet. 

 Above the first of these, for the distance of three 

 quarters of a mile, the canal has a width of one 

 hundred and twenty liiet. The estimated expense 

 of this level is .si5,S7 1,324. . 



The middle division of the work extends thirty- 

 seven miles li'om the head of the first lock. It 

 has six locks, with an aggregate lockage of fifty-_ 

 seven i'eet in the first four miles, for the whole of 

 which distance the route is over little better than 

 solid rock, and is consequently very expensive. 

 Another difficult portion of this division com- 

 mences about two miles below the crossing of the 

 Du Page, and extends nearly to Dresden, below 

 the mouth of the Kankakee. The blufls here are 

 from one hundred to one hundred and fifty feet 

 high, and approach so near the river as to be 

 washed by it, which renders it necessary to con- 

 struct the towing path wholly or in part, in the 

 river, for a distance of more than two miles; con- 

 sequently, an expensive protection will be de- 

 manded to defend the work from the ice-floods of 

 the Kankakee. 



The western division has sixty-eight feet lock- 

 age, and is twenty-nine miles in length, exclusive 

 of four miles of the Fox river feeder. From the 

 first lock, below Ottawa, to the termination of the 

 canal at La Salle, (on section fifteen,) the route 



