I recently acquired an archive of letters and manuscripts related to Prof. Timoshenko from an auction house in US (I paid 12500 US$).
I am currently organizing and storing them in proper way.
A big portion of this collection is his hand writings related to his book "History of Strength of Materials". Many in bad shape and fading due to be written by pencil. Some even have mold. There are also few original hand written versions of some of his papers.
Also an interesting portion is many letters between him and different universities trying to recruit him in 1930s: Harvard, Berkeley, ... letters he received from them and responses he wrote by pencil on paper to send to them.
There is also a canvas briefcase which seems to be his. I thought to share this story. My plan is to scan all these over time, and make them available for public. The following is the address I will post them online:
Regards
Peyman Khosravi
For any questions, contact me at:
peymankhs [at] yahoo.com