The four volumes of diaries contained in the J.P. Lesley Papers coincide with his appointment as Director of the Second Pennsylvania Geological Survey. Spanning 1874-1881, these volumes ought to interest scholars researching the Geological Survey of Pennsylvania, and the fields of applied geology and coal and iron mining more broadly. The first volume (1874) includes pages concerning the creation of the survey, copies of the acts of Congress, and Lesley's commentary on those acts. Notably, he includes a striking topographical map of Pennsylvania, colored for the principal geological formations (p.69). In fact, the third volume (1875-1876) includes a loose topographic map that bears striking similarity to the aforementioned. Finally, the second and fourth volumes (1874-1875 and 1877-1881, respectively) documents ore mining with some attention to fossils discovered.
 

The Alfred P. Rockwell Papers also include other notebooks on mining engineering (some containing sketches), including two volumes of notes on John Percy's lectures at the Museum of Practical Geology, 1858, and three volumes kept during his stay at the Bergakademie Freiberg, including one on a course on metallurgy taught by Bernhard von Cotta, 1858-1859.

The Rockwell Papers do not include any diaries per se. While one notebook is identified as a June 25, 1859 diary, there are only three dated entries (8/31, 9/15, and 11/18), none of which begin on the suggested date. Those entries do, however, include granular details of industrial factories and machinery in Belgium and Germany.
 
The Alfred P. Rockwell Papers also include other notebooks on mining engineering (some containing sketches), including two volumes of notes on John Percy's lectures at the Museum of Practical Geology, 1858, and three volumes kept during his stay at the Bergakademie Freiberg, including one on a course on metallurgy taught by Bernhard von Cotta, 1858-1859.