The tempering and hardening tank at William Cook & Sons' saw factory in Finnieston, c 1910.
This large tank was filled with whale oil and could be wheeled to different locations in the works. Workers were required to slide a newly-made saw from the furnace straight into the tank, to harden and temper the blade. When the red-hot saw touched the oil there was a flash of flame and the furnace team had to immerse the blade quickly in the oil before the flames spread. Clearly not a job for the faint-hearted!
Reproduced with the permission of Glasgow City Council, Glasgow Museums
circular saw blades, saw tempering tank, saws, toolmakers, toolmaking, whale oil, William Cook & Sons