400 Miscellanies. 
27. New Self-registering Barometer; by Rosert Bryson. (Trans. 
Roy. Soc. of Edinb., xv, 1844, 503.)—The arrangement in Mr. Bryson’s 
instrument is as follows :—In the open end of a siphon barometer tube, 
there is a float consisting of an ivory ball, which rests on the mercury, 
and a float rod extending out of the extremity. This float rod is bent at 
right angles at top and shaped to a knife edge, to act as the registering 
rod; and near it a tin cylinder, about three inches in diameter marked 
with the hours, is made to revolve by machinery, once in twenty four 
hours. In this cylinder there is a series of short pins corresponding to 
the hours, which, as the hour arrives, acts upon a bent lever, which presses 
the registering rod against the cylinder, upon which an impression is thus 
left, indicating the height of the barometer at the time. On passing the 
pin, the rod is thrown back by a spring, which is sufficient to shake the 
float and remove any adhering mercury. Mr. Bryson, who describes 
minutely his mode of arrangement, proposes that there should be seven 
cylinders, each marked with a day of the week. To fit them for use 
they are streaked with chalk and water well levigated and applied by a 
camel’s hair brush. 
28. Onthe Manufacture of Enamelled Cast Iron Vessels in Bohemia.— 
Tron pots, and especially those of enamelled cast iron, are very exten- 
sively used in domestic economy. To enamel these vessels, they are 
cleaned as perfectly as possible with weak sulphuric acid, then washed 
with cold water, and dipped into a thin paste made with quartz first melted 
with borax, feldspar, and clay free from iron, then reduced to an impalp- 
able powder, and sufficient water added to form a rather thin paste. These 
vessels are then powdered in “the inside with a linen bag containing a 
very finely pulverized mixture of feldspar, carbonate of soda, borax, and 
a little oxyd of tin. Nothing then remains but to dry the pieces and heat 
them in an enamelling furnace. The coating obtained is very white, T¢- 
sists the action of fire without cracking, and completely resists acid or al- 
kaline solutions.—Chem. Gaz., July, 1845. p. 290. 
. The Tagua Nut or Vegetable Ivory; by A. Connett. (Trans. 
Roy. Soc., of Edinb., xv, 1844, p. 541.)—This remarkable seed is now ex- 
tensively carved into a variety of ornaments, which resemble the finest 
ivory both in texture and color. The nuts are often as large as a hen’s 
egg and somewhat angular in shape, and come from a species of palm, 
(Phytelephas macrocarpa.) Excepting the outer shell, about 3/5 of an 
inch thick, and a brown epidermis, they consist throughout of the close 
grained material called vegetable ivory. Its density is 1°376 at 53° Fabr. 
The analysis afforded Mr. Connel, gum 6°78, legumin or vegetable casein 
3'8, vegetable albumen 0°42, fixed oil 0°73, ashes 0°61, water 9°37, lignin or 
other woody matter 81° 34— 100. _'The ashes contained phosphate of lime, 
sulphate of lime, chlorid of calcium, carbonate of lime and a little silica. 
