Dr. Clarence Hickman
By Boris F. Kim, forwarded by Bruce Clark
Here is a copy of a letter from Boris F. Kim, an acquaintance of Dr. Clarence Hickman, inventor of the model B Ampico.
I do not believe that Dr. Hickman used his spark gap _camera_ to measure speed of piano hammers. Most likely it was the other way around. He developed the spark gap chronograph for Ampico, and most likely used the spark gap principles on his camera. Here is the letter:
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Hello Bruce,
I saw your post on rmmc about your Ampico memories. I don't know much about player pianos but I was an acquaintance of a man who was quite influential in the development of the reproducing piano. His name was Clarence N. Hickman.
Dr. Hickman, who died about ten years ago, was an amazing person who had many varied interests and contributed with his knowledge and inventiveness to many diverse fields. He was primarily a rocket scientist and worked at the Bell Telephone Laboratories for most of his professional career.
During the second world war, he was the head of a wartime project that developed rockets; he in particular was the inventor of the bazooka rocket launcher. As part of his rocket research, he developed a high speed camera (called a spark gap camera) that was capable of extremely high frame rates for photographing rockets in flight.
Hickman was very interested in the sport of archery and is considered by many the father of the science of archery, having made many seminal studies both theoretical and experimental into the mechanics and dynamics of the bow and arrow. He used his high speed camera to photograph the flight of an arrow as it leaves the bow and showed that the arrow bends and vibrates in flight. This phenomenon, which he discovered, is called The Archer's Paradox.
Dr. Hickman was a consultant to the American Piano Company during their development of the reproducing piano. The specific problem that he addressed was how to measure the velocity of a hammer striking the string so that loudness could be accounted for in player pianos. Here he made use of his spark gap camera to measure the speed of the hammers.
I wasn't much interested in pianos when I knew Dr. Hickman, so unfortunately I am not familiar with specific details of his work at Ampico Research Laboratory. I understand, however, that he designed an action that was subsequently used in the reproducing pianos.
In July, 1979, Dr. Hickman (then in his 90's) was invited by AMICA to give a talk on his work at Ampico. The talk was given at the Ben Franklin Hotel in Phila, Pa. I was not present but I understand that the talk was very well received; many in attendance sought his autograph on books about player pianos.
Regards, Boris
Boris F. Kim
Johns Hopkins University/APL
bkim@aplcomm.jhuapl.edu
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(Message sent Mon 3 Feb 1997, 20:19:20 GMT, from time zone GMT-0500.) |
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