This notebook covers the period June-September 1880. The entries are by Charles Batchelor and relate primarily to the electric lamp. Included are notes and drawings of a clamp-making machine; notes and drawings of cutters, shapers, and testers for bamboo fiber; notes and drawings of instruments for attaching carbons and for bending and tapping wires for clamps; and notes and calculations about a new mercury pump designed on the screw principle. There are also notes on the lifting power of palmetto fans, relating to electric balloon experiments; notes on a pump, apparently for water; and notes and drawings of an electric rock drill. The label on the front cover is marked "Batchelor" and "June 28 80." The book contains 284 numbered pages.

Blank pages: 100-221, 224-279.

Missing page numbers: 87-90.