Of course we visited Brunel's block machinery, which shapes from the rough mass of wood, with wonderful accuracy and speed, the polished block fit for use.  Huge lathes were at work, with circular saws and drills, sending the chips of wood flying round them with a whizzing and whirring sound.  So perfect is the machinery that skilled artisans are not required to use it.  Four men only are employed in making the shells, and these four can make with machinery as many as fifty men could do by hand.  On an average, nineteen men make one hundred and fifty thousand blocks in the course of the year.