To fifty chosen Sylphs, of special note,
We trust th’ important charge, the Petticoat:
Oft have we known that seven-fold fence to fail,
Tho’ stiff with hoops, and arm’d with ribs of whale;
Form a strong line about the silver bound,
And guard the wide circumference around.

Alexander Pope, The Rape of the Lock

Here’s an article that might help clear up confusion about the kind of petticoat the Sylphs were guarding in Rape of the Lock: “Why Hoop Petticoats Were Scandalous” – Erin Blakemore