bows like this are somtimes sold as "dragonetti style bows"(although the real dragonetti bow is convex) . if you google/forum search that maybe you get more info.
looks not 1850 to me; and: old is not also = good, this one looks like a very simple made bow to me.
did you buy it? what did you pay?
edit:
here is a nice one from w.e.hill
http://www.vivaceviolin.com/pp/Bows/Bass/BassBw56.html
edit2: OT but new to me info from the above link:
"
The Hills used five different stamps, each one denoting a different quality level. They are, in order of quality top to bottom: W. E. Hill & Sons - W. E. H & S - Hill & Sons England - H & S - Hill. "