… French designers intentionally to create something as different from the crinoline as they could get, and to take advantage of the cheap and abundant fabrics and trims.
By draping techniques, designers pull the large amounts of fabric previously used in the huge round skirt and pulled it to the back. The crinoline had already begun to elongate towards the back, so it was a logical next step.
The surplus fabric was draped and the shape was made by tapes and buttons sewn into the skirt.
To support the weight of the large amount of fabric, the small crinoline of the prior fashion era was brought back, and instead of horsehair and tape, it was made from a steel frame that hung around the waist. In some situations the “tournure” which was twisting layers of horsehair was used in flounces to support the weight of the back of the skirt.
By the mid 1870’s the crinoline was discarded altogether in favor of this “1st bustle”.
(Sketch: wired petticoat or mid 1870’s transition from the elongated large crinoline into the first bustles)