This notebook, which covers the period June-July 1888, is a continuation of N-88-04-18. It contains transcriptions by Arthur E. Kennelly of material from the rough record books used by experimenters in the Galvanometer Room. There are notes, drawings, and calculations regarding armature windings and dynamos, including multipolar and municipal dynamos and a plating dynamo; batteries; non-magnetic watches; and the "new Edison voltmeter." There are also notes on electrocution experiments, the electric light system at Llewellyn Park, and the calibration of instruments, along with calculations on the cost of procuring zinc sulphate. Among the experimenters whose work appears in this book are F. P. Bergh, Arthur E. Colgate, Johannes H. Cuntz, and Oren S. Hussey. Attached to the inside back cover is an index. The front cover is labeled "Record Book No. 3. Galvanometer Room." The back cover is labeled "512." The spine is labeled "48." The book contains 88 numbered pages followed by 8 unnumbered pages. Some pages were removed before the book was paginated. Numerous graphs have been pasted into the book.

The index appears first.