FROST-FORMS ON ROAN MOUNTAIN. 37 



ing toward the center and extending parallel to the face of the 

 disk. 



. On a tumbler, three inches and a quarter in depth and two 

 inches and a quarter in diameter at the top, placed with its mouth 

 to the wind, the result was the same. The frost-forms pointed 

 toward the center and were parallel to the bottom of the tumbler. 

 It might be worth while to find out by experiments how deep and 

 how wide a vessel would be required to cause them to deviate 

 from this rule. 



Fig. 11 exhibits an iron pipe elbow, part of the deposit on 

 which was affected by the rebound from the longer curved side 

 as the wind passed through it. If a straight section of pipe be 

 placed so that the wind may pass through it unobstructed, the 

 deposit is made on the windward end, of the same thickness as the 

 metal ; and it appears as though that part of the pipe had been 



Fig. 10. 



cast in the pattern prevailing in that storm, and whitened. The 

 outer and inner longitudinal surfaces of the pipe are left bare 

 and dry. 



Very pretty experiments may be made with apples, chairs, 

 wheels, tin cans, feathers, and other objects too numerous to men- 

 tion. 



Fig. 12 is an apple with a faithful imitation of a chrysanthe- 

 mum on one side. This was made at a low temperature and was 

 white. The most beautiful blossoms were those made of sleet, at 

 a temperature of twenty-five to thirty degrees above zero. They 



