Meeting Dates
Apr 24 '08
Minutes for April 24, 2008
Present: Not noted.
The meeting was opened by President Sue Carlson. Minutes of the March meeting were tabled. The Treasurer reported a balance of $1,410.28, with $5.00 in dues but a $40.00 postal box bill. The Treasurer's report was approved as read. The suggestion was made that FOFE and EHS merge their postal boxes.
After a brief discussion of mica and its economic importance, during which Marcia pointed out it was added to wallpaper for reflectivity during the times lighting was by candle. Following a brief discussion of the Edgecomb comprehensive plan and the May 6 Gateway I meeting, the meeting was suspended, to reconvene at the Schmid Preserve, Old County Road entrance, to explore the several mica mines on that part of the property.
The Edgecomb Historical Society performed its Rites of Spring by bouncing around the Schmid Preserve's cluster of long-ago mica mines. One piece of graphic granite we turned over had a whole colony of translucent little yellow ants milling around. Gently, we replaced it so they could go on about their business. But were they a distinct species of ant none of us had ever seen before? Or an immature form of a perfectly unremarkable Maine ant? We need a few entomologists on our mailing list!
Let me tell you what I found about mica and fel[d]spar in the Encyclopedia Britannica, 11th edition (1911, which is where my expertise on anything stops!): The variety of mica found in our parts is probably more properly called Muscovite, and was once used instead of glass in stove, furnace and lantern windows, and the chimneys of lamps and gas-burners. Even longer ago it was used for house windows and the portholes of ships. To quote from EB1911, "Powdered mica is also used in the manufacture of paints and paper, as a lubricant, and as an absorbent of nitro-glycerine and disinfectants. Sheets of mica are used as a surface for painting... for lantern slides, for carrying photographic films, as a protective covering for pictures and historical documents, for mounting soft and collapsible natural history specimens preserved in spirit, for the vanes of anemometers, mirrors of delicate physical instruments, for various optical purposes. Being a bad conductor of heat it is used for the packing and jackets of boilers and steam-pipes. Other applications depend on the strength of its resistance to acids. The most extensive application of mica at the present day is for electrical purposes. Being a bad conductor of electricity, it is of value as an insulator, and the smooth flexible sheets are much used in the construction of armatures of dynamos and in other electrical machinery."
Mica occurs as a component of any igneous rock; for instance, in granite, it's the sparkle. Locally, it is often found in association with feldspar, which has been used in the manufacture of porcelain because of its fusibility. As feldspar breaks down chemically, it yields kaolin, the pure white china-clay. Highly translucent porcelain, known as "ivory porcelain" has a large proportion of feldspar in it. It is also an important constituent of most ceramic glazes, and was once used in the making of false teeth. Anyone wanting more current data can go to Wikipedia!
As a result of the above adventure, and still buoyed up by our success at having a marine botanist and a marine molluscologist (is that a genuine discipline?), EHS will plan to invite geologists, paleontologists and archaeologists to grace our meetings in future. Any suggestions? Any volunteers?
Respectfully submitted,
Joanna M. Cameron
Secretary