James Watt is famed for his work improving steam engines. But did you know he also invented a letter copier?

Watt came up with the device to relive him of the tedium of making copies of his plans and drawings. The copier was patented back in 1780 – and the principle remained in use until the arrival of modern photocopiers.

As part of the 2019 Glasgow Science Festival, printmaker Roger Farnham helped set up “The James Watt Print Show” – an exhibition showcasing modern fine art prints created using Watt’s 18th century system.

The pieces developed for the exhibition – by 22 artists – will be available to see (by appointment) at Glasgow Print Studio from November 2019.

At the recent Watt conference at the University of Birmingham, Roger spoke about the exhibition and Watt’s innovative copier. Listen to the interview by clicking the link below.

Roger Farnham
Roger Farnham helped set up an exhibition showcasing the 18th-century method of copying documents, patented by James Watt.

“My name is Roger Farnham.

“I’m a retired engineer. I have known about James Watt since I was at school obviously – because I did physics and engineering afterwards.

“And then I worked in the power industry with lots of high pressure steam – which he wouldn’t have approved off.

“But I also became a printmaker, and printmaking brought me to the conference here … because, James Watt also invented a letter copier, which I kept finding references to as a precedent to photomechanical printing which I’m very interested in.

“So, yes, I’m very pleased to have been able to wangle my way into this fascinating conference about Watt.

“And I think I’ve encouraged some of my arts friends to get very interested – because I worked up as an exhibition using his letter copy process – it’s more the chemistry really than printing …. But it did go through a mechanical press, so it is getting close to photomechanical, my other passion.

“So, the exhibition was part of the Glasgow Science Festival back in June.

“The work actually is going to go into the archive of the Glasgow Print studio. And from November this year you’ll be able to make an appointment to go and see it. So, this work by 22 artists – and all intrigued by using technology that is over 200 years old. They’re all modern-day contemporary artists. It’s been great to see how they’ve reacted to the possibilities of the process.”

Watt's letter copier - picture courtesy of Heriot-Watt University, Edinburgh.
Watt’s letter copier – picture courtesy of Heriot-Watt University, Edinburgh.

How does the Watt copying process work?

“Okay. If you take a business of blotter taking a copy of something when the inks wet. But if you were to wait until you had written the letter, you can only get the bit that was still wet.

“Watt came up with some chemistry that reactivated the ink. Not only that, if you had a blotter copy, it would be in reverse.

“He actually chose a paper to be sort-of translucent. And also, that it would allow the ink to permeate the paper properly – really penetrate it – so you could read it from the other side and read it the right way round.

“So the prints that were in the exhibition actually exploited that, and they’ve got a certain quality because you’re looking at them through the paper. Obviously, it needs special paper to do that.

“Back in the 18th century, it was linen rag paper – not cotton used today. So, it was quite difficult to replicate the constraints he was under back then. But the process hung in there for like 150 years, and there’s only other technology coming along in the 1880s that really superseded it. So it was long-lived bit of technology. So a fascinating project, it was.”

Some of the prints produced for the exhibition are shown below. Click an image to see a larger version.


Roger Farnham’s first exposure to James Watt was writing a first-year university Mechanics of Machines course essay on Watt’s governor. He has been in awe of Mr Watt since.

He worked as a control and instrumentation/systems engineer in the power and oil and gas industries for over 40 years, and has also been a printmaker for more than 40 years. Roger is a member of the Institution of Engineering and Technology and the Nuclear Institute.