[Note 205.3] "they'll have such stunning bustles":- Before the 1860s, the bustle(1) was a simple bum roll and not likely to described as "stunning". Bustles here may be referring to an undergarment which most fashion historians would call a crinoline. The image below is of a horsehair crinoline c1840

[ref: https://en.wikipedia.org/wiki/Crinoline]