While thinking about my next project, an Edwardian underbust corset. I once again started wandering what did the Edwardian ladies wear for bust support. (I know I definitely need some.)
The answer is a Bust Bodice or a bust improver!
Woman's Bust Bodice, 1895
Woman's Bust Bodice, 1902
More early bra's
French Bust Bodice, ca. 1905
Bridal corset. Silk and satin. Britain, 1905.
Bust bodice, by Spirella Corsets. Cotton batiste trimmed with machine lace trim. Britain, c.1908-14.
Edwardian Bust Bodice, ca 1913
A Turn Toward the Bust: Early Twentieth Century
History of brassieres (Wikipedia)
Flickr - Late Victorian Altered Bust Bodice
Bras and Girdles Fashion History
Next question; How do I make one?
I might try something like this:
"...In 1910, Mary Phelps Jacob (known later in life as Caresse Crosby), a 19-year-old New York socialite, purchased a sheer evening gown for a social event. At that time, the only acceptable undergarment was a corset stiffened with whalebone. Polly had large breasts and found that the whalebone visibly poked out around her plunging neckline and from under the sheer fabric. Dissatisfied with this arrangement, she worked with her maid to fashion two silk handkerchiefs together with some pink ribbon and cord.:7  Her innovation drew immediate attention that evening, and at the request of family and friends, she made more of her new device..." source wikipedia