Besides improv ing the dynamo, he perfected with little difficulty a cheap vacuum-globe.
[1878 288 THE CEMENTED UNION Edison, the prodigy of the century in inventive genius, was the most successful.  Besides improv ing the dynamo, he perfected with little difficulty a cheap vacuum-globe.  After long experimenting he succeeded in the more arduous task of seeming an automatic checking of the current before it became hot enough to consume the incandescent carbon.