This may be borderline off-topic but this is the only place that I can think of ask this particular question.
I've always seen images of Leonhard Euler with a "hat" or head covering that is unfamiliar to me.
Is there a name for the head covering shown in Emanuel Handmann 1753 painting of Euler? Does it carry any specific significance of mathematical scholarship?
He wears the head wrap in combination with a silk banyan.
In the 18th century...
It was fashionable for men of an intellectual or philosophical bent to have their portraits painted while wearing banyans. Benjamin Rush wrote:
Loose dresses contribute to the easy and vigorous exercise of the faculties of the mind. This remark is so obvious, and so generally known, that we find studious men are always painted in gowns, when they are seated in their libraries[2].
… [The banyan] was usually paired with a soft, turban-like cap worn in place of the formal periwig.
The fashion was inspired on a style from (exotic) East Asia.
