216 Lake Maxinkuckee, Physical and Biological Survey 



from surface to bottom. So long as the upper end is lighter than 

 the lower, the column will remain upright. But if the metal column 

 should be reversed, bringing the heavy end up and the light end 

 down, any slight disturbance would cause it to reverse itself and 

 again assume the more stable position with the heavier end down. 

 The same is true of the column of water. So long as the colder, 

 heavier water is at the bottom, it will so remain ; but let the upper 

 end of the column become the colder and, consequently, the heavier, 

 it will go down, and the lighter bottom water will come up. That 

 is precisely what does happen. If the series of temperatures from 

 July 24 onward be examined it will be observed that the difference 

 between the surface and bottom temperatures becomes successively 

 less. By the 23d of November, 1900, the difference was only .5 

 of a degree, the surface being 46.7° and the bottom 46.2°. Some- 

 time between the 23d and the 26th, probably on the night of the 

 24th, the temperature throughout the upper half of the column 

 fell below 46°, or lower than that of the lower end of the column. 

 The upper half of the column then being the heavier, it of necessity 

 went to the bottom, the bottom half came up, and the temperature 

 of the lake became uniform throughout. This is shown by the 

 serial temperature readings of November 26, which show that the 

 temperature at all depths from top to bottom was 44°, a condition 

 which practically continued until the ice went off. It can there- 

 fore be safely assumed that, in 1900, Lake Maxinkuckee "turned 

 over" some time between the evening of November 23 and the 

 morning of the 26th; and what occurred then, in all probability, 

 occurs every November or December. 



The highest surface temperature recorded at the Deep Hole was 

 83° on August 11, 1900, the bottom temperature at the same time 

 being 49.9°, the difference between surface and bottom being 33.1°. 

 The lowest summer bottom temperature obtained in the Deep Hole 

 was 48.7° on August 31, 1899; the lowest recorded at the Kettle- 

 hole was 48.5° on September 8, 1899. 



CONDITION OF 'THE WATER 



Clearness: — The water of Lake Maxinkuckee is generally com- 

 mented upon by visitors, and boasted about by the natives, on ac- 

 count of its clearness and purity. 



After a long sojourn at Winona Lake, Indiana, paying particu- 

 lar attention to the lake, a visit to Lake Maxinkuckee excited a 

 marked sensation of surprise at the clearness of the water; in 

 Winona Lake it was somewhat tea-color; at Lake Maxinkuckee, 



