296 Facts relating to the Great American Lakes, 



of the lake, and distant about sixty miles, the same fall and 

 rise were observed to be repeated, the greatest being a little 

 before sunset, when the waters rose to their highest point, or 

 about two feet. In the efflux, the shores had in many places 

 been left dry for some minutes. At Port Hope, a iew miles 

 west of Cobourg, the steam-boat Princess Royal ran aground 

 as she attempted to enter the harbour, so much had the waters 

 lowered in the port. 



The cause of this phenomenon is doubtless to be found in 

 the tornado which passed that afternoon over the lake, be- 

 ginning at Johnston's Creek in Niagara County, and passing 

 in a north-east course over Orleans County, till it struck the 

 lake at Oak Orchard Creek, fifty miles west of Rochester, 

 and continued its course across the lake. The tornado was 

 about three-fourths of a mile wide in Orleans County, and 

 was very destructive, twisting off and bearing away large 

 trees, unroofing and destroying buildings, &c. Its violence 

 was of only a h\v minutes' duration, perhaps not over three. 

 On the lake it produced water-spouts, and was attended with 

 large hail, and lightning and thunder. The steam-boat Ex- 

 press, Captain Mason, was in great jeopardy from the wind 

 and waves, and storm, as she was then passing up the lake on 

 her regular trip. The power of this tornado was probably 

 sufficient to withdraw the waters from the shores, so as to pro- 

 duce the efflux and reflux that was witnessed. Such sudden 

 changes of the level of the waters are said to have been wit- 

 nessed before on the lakes. The solution in this case may 

 apply to the whole. It seemed desirable to collect and con- 

 nect the facts in this case, and to publish them, as they pre- 

 vent a resort to supposed earthquakes heaving the bottom of 

 the lakes, or change of the level of the shores, of which not a 

 trace is left, and not a probability exists. This tornado does 

 not appear to have moved rapidly, but to have derived its 

 force from the great rotatory velocity, as it twisted off trees, 

 breaking them more than overturning them. A lumber wag- 

 gon was raised into the air, and carried a considerable dis- 

 tance. A stick of timber, which required eight men to carry 

 it was removed to the distance of fifty roods. On the lake, 



