I Have Not Failed. I've Just Found

I Know Of Over 3,000 Ways [that] A Light Bulb Does Not Work.

We Shall Have No Better Conditions In The Future If We Are Satisfied With All Those Which We Have At Present.

I Never Did Anything By Accident, Nor Did Any Of My Inventions Come By Accident; They Came By Work.

Because Ideas Have To Be Original Only With Regard To Their Adaptation To The Problem At Hand, I Am Always Extremely Interested In How Others Have Used Used Them.

I Have Friends In Overalls Whose Friendship I Would Not Swap For The Favor Of The Kings Of The World.