For a number of years I owned an invoice from Thomas Long & Co., Engineers and Machine Makers in Edinburgh, for work done for the Edinburgh booksellers and publishers William Blackwood & Sons. I recall purchasing this three-page document because the billhead stated in very small print: "Platten and Cylinber Printing Machines; Columbian Presses & Self Inking Machines. Hydrostatic Presses." In even smaller print at the bottom the engraving on their billhead is signed "Lizars sc", Lizars were famous engravers in Edinburgh. At the time of purchase I was unsure of the historical value of this document. Now, having done more research on the history of printing in this period, I believe that this modest and somewhat difficult to read document provides valuable details regarding Blackwood's printing operation in 1858- details that may not be available elsewhere.
From this detailed invoice we may infer various details concerning Blackwood's printing operations:
1. They operated at least 5 printing machines, numbered 1-5.
2. They operated at least one Columbian handpress.
3. They operated at least one double cylinder machine.
4. They operated several hydraulic presses.
5. They operated several inking or self-inking machines.
6. A significant number of Blackwood's machines required service during the six months for which Thomas Long was invoicing the firm. The implication might be that Blackwells were using older equipment or else they were working their presses hard and burning out parts.
7. On several occasions a smith had to forge parts for some of the machines.
8. For driving printing machines Blackwood operated at least one steam engine that required repair. The invoice refers to it simply as an "engine".
9. Technicians from Long visited Blackwood's plant several days each month, but especially in the month of October, when they made 10 service calls. We might infer that Blackwells did a great deal of printing during October. Altogether in the 6 month period the technicians provided service or parts on 27 days, and on many of those days they serviced more than one piece of equipment.