Coal scuttle bonnets were popular in Victorian 1840s through the 1850s. Their shape is similar to the pail that held coal hence the name coal scuttle. The ties range from 2-3" wide and get wider towards the 1850s.
Pattern: McCalls M5129 has several versions to make up coal scuttle bonnets. View C has three pattern pieces, crown, brim, and top. The crown is much smaller and the brim much larger than later 1850-60s bonnets.