A Treatise on Meteorological Instruments - Negretti & Zambra Seven Day Razor Set but this seemingly simple conundrum

but this seemingly simple conundrum must have been too enticing to pass up

This rare and early example is comprised of a Bakelite rectangular base with input to the front for an additional discharge wand and the manufacturer transfer to the front stating “Physica”

The dome top of the case is mimicked within the scale plate by a separate domed piece of glass

Henry Gregory

As if all of the above was not enough

A Treatise on Meteorological Instruments - Negretti & Zambra Seven Day Razor Set but this seemingly simple conundrumThis treatise on meteorological instruments was first published in 1864 by the partnership of Henry Negretti and Joseph Zambra, meteorological instrument makers to Queen Victoria, and describes the method of construction, scientific principles and practical uses of barometers, thermometers, hygrometers, rain gauges, anemometers, electrometers, ozonometers and other meteorological instruments. The instruments are fully described, with the help of