Albert Einstein at Lincoln University, Pennsylvania, May 1946. pic.twitter.com/VYBNjGpirk

— ✍ Bibliophilia (@Libroantiguo) February 10, 2015

Air and Space Building - a precursor to the Museum - in the south yard of the Smithsonian castle, 1974 [photo by... http://t.co/VoeYqBuAQa

— old_time_DC (@old_time_DC) February 9, 2015

Though this photo was taken only six years before I started working in the A&I Building, NASM had long disappeared from this site when I arrived.

Russian writer Leo Tolstoy playing chess with the son of his friend Vladimir Chertkov who took this picture in 1907 pic.twitter.com/HmUFkVUmPr

— ✍ Bibliophilia (@Libroantiguo) February 9, 2015

Early google glass “@oldpicsarchive: Inventor Hugo Gernsback is Demonstrating His Television Goggles in 1963 pic.twitter.com/JfgOo9c5Ip”

— Tiffany Shlain (@tiffanyshlain) February 9, 2015

Leonardo da Vinci’s Handwritten Resume (1482). "In case of need I will make big guns.” http://t.co/5dS5OviXBr pic.twitter.com/J63e53wOcu

— Open Culture (@openculture) February 7, 2015