On Monday 23 January 1922, the Adelaide Register, South Australia, reported on a teasmade invented by Herbert James Karslake. This is the earliest record I have found of his invention. The article reads:
A device that automatically makes an early morning pot of tea has been invented by Mr H J Karslake, the Ilfracombe, Devon, sanitary inspector. Explaining it he said:— “You set an indicator to the time you want tea in the morning. When that time arrives the apparatus turns on the gas under the kettle. When the water boils the tea is immediately transferred to the teapot, and the gas is automatically turned off. A bell is rung, the electric light switched on, and the sleeper awakes to find a pot of tea ready.”
On December 14th 1922 the North Devon Journal reported on a Wesleyan Sale of Work at which Herbert was exhibiting his model electric railway. Sadly there are no details of who bought the invention. As a postscript to the article the reporter mentions:
Mr Karslake has just sold an ingenious invention in the shape of a “magic kettle” which sounds an alarm, lights the gas, boils the kettle, and makes tea, then switches on the electric light, with another bell to say that all is ready for the early cup of tea.
Herbert applied for a patent for improvements to his invention on 10th September 1923, application number GB3364722A. The application was published on 15th May 1924.