People with an interest in "lung power" may be aware that during the late 19th and early 20th century, penny arcades often included various types of strength testers. These, in turn, often included a "lung tester," which tested lung capacity, blowing pressure, or breath-holding ability. These machines are rare today, in part due to having been outlawed in public spaces for their role in spreading tuberculosis. At the Laboratory, we have long been curious about the devices that measured pressure. Namely, how much pressure was required to light the top lamp, push the needle to the end of its ...

People with an interest in "lung power" may be aware that during the late 19th and early 20th century, penny arcades often included various types of strength testers. These, in turn, often included a "lung tester," which tested lung capacity, blowing pressure, or breath-holding ability. These machines are rare today, in part due to having been outlawed in public spaces for their role in spreading tuberculosis. At the Laboratory, we have long been curious about the devices that measured pressure. Namely, how much pressure was required to light the top lamp, push the needle to the end of its scale, or otherwise achieve the maximum reading? Those few surviving examples of these devices sell for tens of thousands of dollars. Fortunately, we were able to find just the mechanism from a c. 1904 Caille Brothers Mascot lung tester, and perhaps other models. It was represented as a reproduction, although it looks extremely authentic. While we can't know if the springs are equivalent to the original, it does look just like photos we've seen of original mechanisms. The mechanism consists of a piston attached to a rough-cut arm, which apparently operated a series of electrical contacts to light six lamps. So for our test, we divided its travel into six equal segments in order to get an idea of how much pressure might have been needed to light the six lamps. Dolly uses our digital pressure recorder to see how linear the cylinder's travel is, and what pressure is required to blow it to its maximum.