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Gas-fired DeLamater Ericsson in action

Brent Rowell

Just finished a "reconditioning" of this engine. I won't call it restoration since I only needed to add the air chambers, rebuild the pump and get a new piston leather. It is nearly as nice as when it left DeLamater Iron Works in New York City in the late 1880s-early 1890s: no wear in any of the bearings and runs as quiet as a mouse, or at least as a rat. The first DeLamaters from the early 1880s had a simple cylindrical pump, shorter water jacket, lighter flywheel, and thinner, weaker linkages. The improved version got a new pump designed by Thomas Rider (son of Rider engine inventor A.K. Rider), beefier linkages and a heavier flywheel. Thomas Rider, in charge of all hot air engine production at DeLamater at the time, also patented an inner sleeve used inside the hot cylinder to increase efficiency.

Here's the video:

Brent Rowell

I don't know the answer to your question. The inner sleeve was patented by Thomas Rider when he worked at DeLamater Iron Works but was apparently not used later when DeLamater became part of Rider-Ericssson. Thomas did not join the new company but I assume the company owned his patents.


New member
Hi Brent,
it would be interesting if you opened two new threads:

DIFFERENCES between the various RIDER pumpers manufacturers
DIFFERENCES between the various ERICSSON pumpers manufacturers

what do you think about it?

Best Regards