The bracelets are in my possession, and everything I could wish them to be. They came with Martha's pelisse, which likewise gives great satisfaction. Jane Austen to Cassandra December 9, 1808During the Regency, there was a mania for everything ancient-- Roman, Grecian, Egyptian-- part of this exotic look was gained by the use of "armlets"-- bracelets made for your upper arm. They are quite common in portraits of the time, and though popular for the decades, show up in fashion magazines and plates particularly from 1809-1818. The following quote, on the wearing of gloves, from Mirror of Graces; or the English Lady's Costume (1811) shows that they were also used as "garters" to hold up long gloves, if one's arms were not particularly attractive.
If the prevailing fashion be to reject the long sleeve, and to partially display the arm, let the glove advance considerably above the elbow, and there be fastened with a draw-string or armlet. But this should only be the case when the arm is muscular, coarse, or scraggy. When it is fair, smooth, and round, it will admit of the glove being pushed down to a little above the wrists.
The following fashion plates give even more examples of armlets.
A turban a la Greque, of pale yellow and silver, the hair in small ringlets round the face; diamond earrings, and armlets, either with or without necklace. Sack dress of pale yellow, trimmed with silver, white satin shoes, and white kid gloves. Le Beau Monde, and Monthly Register, 1806-1810 Volume 1 , No. 2 May, 1809
From Ackermann's Repository of The Arts, 1818
Evening Dress: A black crape frock over a black sarsnet slip: the body is composed of white crape, tastefully ornamented, with deep vandykes of black velvet, each vandyke finished at the point by a little light ornament of black chenille. Short full sleeves of intermixed black and white crape, fulness drawn to the middle of the arm, confided in three separate folds by vandykes of black velvet. The bottom of the skirt is finished by a row of black velvet vandykes, surmounted by a large rolueau of white crape, entwined with black chenille; two rows of roses composed of black crape mixed with chenille complete the trimming. Headdress, a white crape toque, is ornamented around the front in chenille and finished by a diadem of white crape roses. Earrings, armlets, necklace and cross composed of jet. Black chamois leather gloves and slippers which are ornamented with rosettes of white chenille. A black China crape scarf, richly worked at the ends in an embroidery of white flowers, is finished by a black silk fringe.