I am scattering around to find the first use of the idiom "long face" or "long-face" as in "why the long face?", meaning to show in one's facial expression a low, drooping melancholy or blue sadness. This idiom has always been a favorite of mine as the imagery of it is quite fantastical and wondrous indeed, I can't help but think of Edvard Munch's The Scream when I hear it.
Distionary.com sets the etymology of the expression "long face" to 1780-90, and Merriam Webster to 1747 (a very particular year to say the least, so I would indeed not doubt the first use has been discovered previously)- but of course, as is common in seeking to discover the origins of idioms, they are in many cases untraceable.
Online Etymology Dictionary states:
A long face, one drawn downward in expression of sadness or solemnity, is from 1786.
I unearthed 27 examples of "long phase" from 1571 to 1700, all being mere physical description, so I am assuming, although I have no conviction on this assumption, that the word is probably younger than 1700.
Here is a delightful example of the physical description use of the word 1666:
it is accounted beauty to have a long face, lean cheeks, and excessively big legs:
Upon further research, I too, like @Sven Yargs found my earliest example in "Philosophical Transactions and Collections:" from 1743 which mentions the word as "commonly used".
Any insight on this would be humbly appreciated.
Thank you most sincerely in advance.
Best Answer
The following physiological explanation of the phrase "putting on a long face" appears in James Parsons, "The Crounian Lectures on Muscular Motion, Lecture II. Read Nov. 27, 1746," reprinted in The Philosophical Transactions (From the Year 1743, to the Year 1750) Abridged (1756):
So, evidently, "putting on a long face" was already a commonly used phrase in November of 1746, and it refers to the physiological effect on the appearance of one's face that results from tightening certain facial muscles and relaxing certain others when weeping. A second version of these lectures was published in 1747, so perhaps Merriam-Webster is dating the idiomatic use of "long face" to that publication, instead of to the public reading of the lecture in the previous year. In any event the expression seems to have been well established by 1746.
The expression also occurs in Samuel Richardson, Clarissa; or, The History of a Young Lady (1748) in a letter from Mr. Lovelace to John Belford:
One early text draws an interesting connection between having a long face and having a tendency toward melancholy. From a 1665 translation by John Davies of Marin Cureau, The Art How to Know Men, Originally Written by the Sieur de La Chambre:
But as used in this treatise, the term "long faces" isn't an idiomatic description of people whose faces seem to grow longer at moments of melancholy. Rather it describes a permanent physical attribute that naturally accompanies a certain personality. For the sieur de la chambre, it seems, physiognomy is destiny.