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shoulder bones, together with a tooth, were brought here ; but 

 whether or not the tooth was sent to Red River with the shoulder 

 bones, I cannot ascertain. On reaching Shell River last fall, I 

 carefully examined the spot where the Indians laid the bones, 

 and found them ; but having been buried, they had decayed so 

 much that they fell to pieces on being touched. A portion of a 

 large bone, and some fragments of what is supposed to have 

 been a tooth, I brought here ; these will be carried to Norway 

 house next spring and disposed of as you may direct." 



Prof. W. B. Rogers presented the results of calculations, 

 which he had lately made, of the terminal velocity of rain 

 drops of different diameters. 



As the impinging force of the drop must in all cases depend 

 on its weight and velocity jointly, the determination of the latter 

 quantity, even approximately, would seem to be of considerable 

 interest in connection with the subject of rain-drop impressions, 

 which Prof. Wyman has begun to investigate with so much 

 success. 



Were the space around the earth a vacuum, a falling body 

 would continue to be accelerated at a nearly equal rate to the 

 end of its descent, and would not attain to its maximum velocity 

 until the moment of its impact on the ground. Such, however, 

 is not the condition of a body descending through the atmos- 

 phere. The particles of air lying in its way oppose a resistance 

 to its motion, and this force increases in a very rapid ratio as the 

 velocity augments. There will therefore in every case be a 

 certain speed at which this resistance acting upward will pre- 

 cisely equal the weight of the falling mass, and when this is once 

 attained all further acceleration must cease. In these conditions, 

 supposing the air to be of uniform density down to the earth, the 

 body will fall though the remaining distance at a uniform rate. 

 This terminal velocity, therefore, is obviously the greatest speed 

 which, under the conditions, the body can acquire by descending 

 through the air, however great the altitude from which it may be 

 supposed to fall. 



Assuming, what is probably in most cases the fact, that the 



