NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Illinois drainage
From: George Huxtable
Date: 2005 Nov 21, 11:09 -0000
From: George Huxtable
Date: 2005 Nov 21, 11:09 -0000
To be honest, this isn't really a question about navigation, but about geography and hydraulics. But some Nav-l contributors hail from the Illinois area, so perhaps know the answer. I've been reading an odd book, published in 1911, The Log of the "Easy Way". This is about the voyage of a young couple, in 1900-01, in a house-boat or "shanty-boat", drifting down the Mississippee to New Orleans. The journey started in Chicago, with a tow through the "Old Canal", which presumably was later enlarged into the present Ship Canal. Then down the Illinois River to the Miss. The book took my interest as it took in the same stretch of the Miss., between St Louis and Cairo, as had been used by Lewis and Clark, a century before, to reach their official setoff point. I'm aware of (and have always been rather puzzled by) how close the drainage of the Miss. basin comes to the Great Lakes, West of Chicago, but have presumed there's a narrow watershed, close West and South of Lake Michigan, which prevents that lake from spilling over to end up at New Orleans. And yet, in this book, the author, having reached the Illinois River, comments after passing La Salle / Peru, that "Its water may come from the cold, clear depths of Lake Michigan but ... ". Surely not, I surmise. If that had ever been the case, the watercourse would have eroded over the millennia to become, by now, a torrent. Is it even hydraulically possible, even if the ground West of Lake Michigan is permeable to underground flow? That would require the water level in the upper Illinois to be lower, with respect to sea-level, than is Lake Michigan, at 580 feet? Is that the case? Presumably, there's a dividing line somewhere, on one side of which, if you pee on the ground, it will end up in the St. Lawrence, and on the other side, in the Gulf of Mexico. How far do you have to travel from Lake Michigan, to reach that line? It's not an important matter, but it interests me. George.