This is a Zero Setting rain gauge by illustrious makers, Negretti & Zambra, London. The instrument would have been produced in the early 1920s as it first appears in this design in their M2 catalogue of that decade, see extract. The simple mechanism operates on the tipping bucket principle and 'tips' on 100th of an inch and will record up to 12 inches on the smaller scale at the top of the dial.
It still has its original leaf catcher which should allow rain to continue down through the centre hole, also the two fixings at the base are still in place. Although made of copper few have survived (even fewer with a zinc case), therefore quite rare.
I was given this in 1960 after I was in charge of taking weather records at school (as a punishment!). See my 'About Me' page. So I've owned this for over half its life. It has been kept in storage for many years. It works ok but would benefit from a good clean. I would very much like to see it go to a good home.
212mm square x 255mm tall