Archie Frederick Collins
MIGLIORA LA TUA RICERCA
MIGLIORA LA TUA RICERCA (clicca per aprire/chiudere)
The Boys' Book of Engine-Building
This boy was Bion J. Arnold, now our fore most American engineer. He was only thirteen years old when he built his first engine — and it worked, too. It was a little horizontal steam affair about seven inches long, and he went about building it in the right way — that is he made patter ...
Wonders of Chemistry
The recent World War brought us to a sharp realization of just what chemistry may mean for us in the future, either for weal or woe. On the one hand it produced insidious gases, powerful explosives and the deadliest agents of destruction that the world ever witnessed. On the other, it ...