Casgliadau Arlein

Handwritten in pencil on off-white, blue-ruled paper. Two pages (with notes on the front of the first page and the back of the second page) of notes and calculations relating to Penallta Colliery. Dated 25 July, 1925. 83.184I/70 (32-37) are pinned together. Loose within a beige/light brown file with all other documents with the accession number 83.184I/70. The file is labelled 'Steam and Electric Collieries'.