An old lady in a pharmacy misunderstanding the use of a thermometer: she thinks the ambient temperature will adjust to match a setting on the thermometer, rather than vice versa. Wood engraving after C. Keene, 1887.

Dialogue includes: Mrs. Purkset (née Gamp). "Please, sir, I want one o' them thum - um - things, yer know, sir, as reggylates the 'eat of a room." Chemist, "Thermometer, you mean, ma'am, I suppose?" Mrs. P. (eagerly). "Yes, sir, that's it, sir. And if you'll be s' kind, sir, to set it to 'sixty five', 'cause that's what the doctor says I'm to keep the room at!!"