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What test? The traditional corned-beef tin is a symmetrical trapezium in frontal elevation, thus one end is smaller in area than the other. OK if you have tag and twisty key; if not you need the Profile. To ensure the contents can be pushed out neatly in one piece, you need to remove both ends and it’s the short-radius corners on the smaller end that test cheapo openers. Easy with the Profile and no jagged edges. One caveat: even the Profile suffers wear, notably the cutting disc and the sprocket that “drives” the tin. Be prepared to replace the Profile in a dozen years or so. But then perhaps you don’t eat corned beef.
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FANCY THAT I write a lot and take a physically active break now and then. Hence the piano keyboard. No big deal, often just hymns. Did you know the seventh and eighth lines and one note of the ninth of Ye Holy Angels Bright:
Or else the theme,
Too high doth seem
For…
are a C-major octave plus one? Makes things easy.