Tag Archives: chimneys

Chimneys and Black Boxes —Leigh Instruments




Photo from the Carleton Place and Beckwith Heritage Museum

In the summer of 1969 the chimney came down as Leigh Instruments stepped up its efforts in the field of pollution. The chimney, which was once a Carleton Place landmark, became a pile a rubble on the bank of the Mississippi River and was no longer a symbol of industry activity.


Photo from the Carleton Place Canadian files– from the Carleton Place and Beckwith Heritage Museum

Even though the once factory chimney was a sign of good and evil-it once was a producer of dirt and grime in towns all around the world. It was said during the first flush of the Industrial Revolution, the smoke from the factory chimneys was so dense that people had to grope their way through the streets in the middle of the afternoon in the British midlands.




Finance Department in 1968.. Thanks Nancy!- Photo-Carleton Place and Beckwith Heritage Museum






Photo and files from-Carleton Place and Beckwith Heritage Museum


Did you know that the first “black box”, or Crash Position Indicator was developed right here in Carleton Place? A unique system for locating a downed plane, its passengers and the flight recorder, this brainchild of Harry Stevinson, an engineer with NAE’s Flight Research Laboratory, was first manufactured and marketed by the Avionics Division of Leigh Instruments Ltd., in the early 1960’s. They were made of fibre glass and foam but tough.

There was a story that one time the Air Force showed up as one accidentally went “off” at Leigh Instruments and there was concern a plane had crashed in CP. The  helicopter swirled over homes and  used the river as a guiding landing strip. It landed in the parking lot and the tailwinds blew lawn chairs every where.


Ray Paquette This is not a black box-if they called it that, it was misnamed. This is a “crash position indicator or CPI” which simply broadcasts a homing signal for SAR aircraft. A “black box”, which is actually day glo orange in colour, monitors and records various readings from the aircraft operating systems, e.g., the engines. Actually the “black box” has two components: the monitoring component; and the “cockpit voice recorder”…

Susan Mary Risk I did soldering, prepping for Conap and stamping on those, made by Leigh Instruments for the Navy, and they were called black boxes back in the day!


Jeff Dezell Back in high school there was a search and rescue helicopter landed on the west lawn of CPHS. Apparently the door of the testing lab for the crash indicator was left open…caused quite a stir during typing class I recall…otherwise dull day got hectic!!

Ray Paquette As a follow on to this post, I wonder how many CPI’s were deployed from downed aircraft that actually led to a rescue of crew or passengers?🤔

In 1975 Leigh Instruments laid off 27 workers in Carleton Place and assured creditors they were solvent.




Remembering Industry in Carleton Place- Digital and Leigh Instruments

Bomb Scare in Carleton Place