I love this little letter. The bulk of the letter is that of R. L. Thompson. He writes to Edison to inquire whether Edison believes the next 50 years will continue to be as technologically and scientifically productive as the last few had been. 

1900 to 1904 saw the introduction of air conditioning, the zeppelin, escalators, radio receivers, the lie detector, EKGs, the first powered flight, radar, diodes, neon lights, tungsten light bulbs, and, perhaps most importantly, tea bags. 

Thompson wants to know Edison's view as to whether that pace is sustainable. 

I think what I love best about it is that Thompson says he could write on and on about it, and the letter itself is unnecessarily chatty. 

And to this inquiry, Edison responds simply "Yes, Edison." Almost as if to say, yes, if chatty-mouths like you will leave the people who are doing the work alone, i.e. Edison, we should be able to continue at a very good clip. 

In very good condition. Authenticity unconditionally guaranteed.