Carbon print by Thomas Annan of William John MacQuorn Rankine, C.E, LL.D, Professor of Civil Engineering and Mechanics.

Thomas Annan was a Scottish photographer who utilized many photographic processes throughout his career. He made portrait and architectural photographs with equal ability, but is primarily remembered for his studies of the alleys and tenement buildings of Glasgow. The Old Closes & Streets of Glasgow (1868-71), a classic of documentary photography, has gone through multiple editions in albumen print, carbon print and photogravure portfolio, and book forms. He was the founder of the firm T. & R. Annan & Sons, and was the father of J. Craig Annan, also a noted photographer and photogravure expert.