54 MODERN SCIENCE READER 



by his invention of compressed steel, next by making the 

 guns breech-loading, and finally by increasing the size of 

 the powder chamber, that it began seriously to be doubted 

 whether any armor could be made able to resist the crush- 

 ing force of the square-headed Whitworth projectiles. 

 Whitworth himself attacked the new problem, and in 1877 

 prevailed. He made plates of compressed steel, built in 

 hexagonal, each of which was composed of a series of con- 

 centric rings around the central disk. The rings prevented 

 the spreading of a crack beyond the one in which it 

 occurred. Of this material a target was composed nine 

 inches thick, supported by a wood backing against a sand 

 bank. In front a horizontal iron tube was put to receive 

 the fragments of the shot. Against this target a Palliser 

 shell weighing 250 pounds was fired point blank from a 

 nine-inch gun, with fifty pounds of pebble powder, at a 

 distance of thirty yards. This shell would have passed 

 through twelve inches of ordinary armor; against the new 

 target it was shattered into innumerable fragments. The 

 target was drawn back eighteen inches into the sand. The 

 fragments of the projectile, escaping at the end of the 

 tube, continued their rotation in such a manner as to cut 

 through the planks in front of the displaced target. The 

 only piece that survived the shock was a flattened mass of 

 eight pounds, formed from the apex of the shell and left 

 embedded in the target, where it had made an excavation 

 of eight inches in diameter, and four tenths of an inch 

 deep in the deepest part. The ring which received the 

 shot was not cracked. 



This experiment alone effected a revolution in naval 

 armament. 



There is not room here to speak of Sir Joseph Whit- 

 worth 's eminent services to the cause of technical educa- 

 tion. He has devoted a large part of the great fortune 

 won by his inventive genius to the founding of schools and 

 scholarships for the benefit of young men desiring to ex- 

 plore the wide field of mechanical industry. 



