quarl
/kwɔːl/noun
Originally: a large brick or tile, especially a curved firebrick. Now specifically: a refractory channel in the wall of a furnace, boiler, etc., through which the flame of a burner passes.
Origin
Late 19th century; earliest use found in Robert Hunt (1807–1887), chemist and photographer. Originally a variant of quarrel, with elision of the unstressed vowel in the second syllable, now distinguished in form in the senses below.