These two books contain a daily record of hours spent making repairs at the Ogden works. One book covers the period June-September 1900; the other covers the period July-October 1900. Sixteen loose pages were inserted into the books. These consist of typewritten documents bearing Edison marginalia and a table of calculations in Edison's hand. The typewritten documents summarize the causes of breakdowns and list various work and repair activities. The summary for mill no. 1 covers the period May-August 1900; the summary for the crusher plant covers the period from May-July 1900. Only the loose pages have been reproduced. Courtesy of Thomas Edison National Historical Park.