1863.] 



459 



the water-line, and the inside surface had increased in depth '35 inch 

 (see fig. 7). 



The upper edge of the small cylinder was reduced in circumference 

 3*6 inches and the lower edge *65 inch, while the greatest contrac- 

 tion at about one inch above the water-line was 4-6 inches ; and the 

 internal surface had increased *15 inch in height (see fig. 8). 



Experiment 5. A solid cylinder of wrought iron, 3 inches in dia- 

 meter and 6 inches deep, was heated and cooled by being immersed 

 half its depth in water fifteen times. 



The greatest contraction took place a little above the water-line 

 and on the lower edge, being in each case *45 inch ; the upper edge 

 was reduced only ! inch. 



Fig. 9. 



One-half of full size. The dotted lines indicate the original form. 



A swell of metal took place on the two ends, but was greatest on 

 the bottom, or that cooled in water, being '15 inch in height. 

 The fibre of the iron opened at the fifteenth cooling (see fig. 9). 



