Of all complex scientific instruments, probably none has been in use for so long with such few fundamental changes as has the petrographic microscope. The instrument used by today’s students doesn’t differ much from that used by Harry Rosenbusch to teach visiting North American geologists the new science of optical petrography in the 1870s. Well, today the microscope is made of light metal and plastic rather than brass, we may focus by moving the stage rather than the tube and view our sample with both eyes, and we’ve forsaken the candle as our light source, but those details aside, the...

First Page Preview

First page PDF preview
You do not currently have access to this article.