Here in the UK Ross Zeiss Protar lenses were quite common before WW1, Ross made Zeiss & Goerz lenses under licence.
Edwin Smith used 3 EWA Protar lenses, the serial numbers show they were all made in 1919 not pre-WW1. EWA is Extreme Wide Angle
Protar 1:18 f=32cm 341102
Protar 1:18 f=14cm 341081
Protar 1:18 f=8.5cm 340946
These are not the typical Protar, but they are all cemented front and rear cells, so only two internal air/glass surfaces, like Dagors. He probably got them cheap as they are barrel lenses, and most people wanted lenses in shutters, but his Ruby field camera would have had a Between Lens TP roller blind shutter.
So his lenses were all f18 widest aperture, I have an AM (Air Ministry) Ross EWA it's a Protar, but they were f16 not f18, Surprisingly it's easy to focus just need a little longer under a dark-cloth.
Ian