While today everyone pretty much buys everything on Amazon.com or some other online retailer back not all that long ago catalogs provided a way for people to browse products from the comfort of their homes. This interwar catalog from Ellwood Hats Ltd. successors to J. Ellwood & Sons of London shows how sun/pith helmets were marketed.
Figure 1. Top left, an Ellwood & Sons ‘Air Chamber’ military sun helmet, patented 1851, following traditional Indian designs it has a light weight cork construction, is cloth covered and has an ‘air pipe’ comb allowing air to freely circulate in the dome. Top right, a ‘Custodian’ police helmet by Christys & Co ltd (1952), uses almost identical construction methods; a version of this basic design was introduced in 1863 and was the only Custodian type for at least 10 years. Bottom left, a development of the sun helmet; a Christys & Co Ltd, late 1800s Colonial Pattern Sun Helmet. Bottom center, the attached Christys label. Bottom right, a near identically constructed police helmet, again by Christys, offered to the police as an alternative ‘Custodian’ style in the mid 1870s.