166 Miscellanies. 
23. Purification of olive oil, for chronometers, §c.—(H. Wilkin- 
son, in Trans. Soc. of Arts, &c. Vol. XLVIILI, p. 43.)—The best 
olive oil, in considerable quantities, is kept in jars for one year or two, 
(in a state of repose,) during which time most of the water and mu- 
cilage subside. Two or three gallons are skimmed from the surface 
of a large jar, and afford better oil than any subsequent portion. One 
gallon being placed in a cast iron vessel of twice that capacity, is heat« 
ed for one hour, over a slow clear fire, to 220°, and must never be 
hotter than 230°, nor descend below 212°. Thus the water and 
acetic acid are evaporated. The oil is then exposed to a cold of 30° 
to 36°, for two or three days; (winter is of course preferable ;) the 
congealed portion is separated by a muslin filter; the solid part may 
be used for common purposes, and the fluid part is then filtered 
through newly prepared animal charcoal, coarsely broken, and sus- 
tained on bibulous paper, in a wire frame, within a funnel ; this re- 
moves rancidity, if any is present, and the oil becomes perfectly 
bright and colorless. 
Messrs. Barraud and son, (the celebrated chronometer makers in 
London,) attest that this oil is superior to any other, and that they 
have used no other for the last four or five years. 
The process is simple and easy, but it demands considerable time; 
it has been used by the discoverer for ten or twelve years. 
24. Method of clearing the Baltimore rail-way of snow during 
the late winter.—It was 
invented by Mr. Winans, 
and consists of an angular 
frame, shod with iron, == 
followed by a sled, shod with irons oblique to the line of the runners; 
the first pushing the snow each way off; the latter scraping snOW 
and ice more closely, as the oblique irons in succession scrape '® 
rails. It was drawn by five or six horses at a trot ; and was effect 
ual, though the snow was two feet deep on a level; in the deep p* 
es, much more.—( Communicated by Mr. J. L. Sullivan.) 
25. Discourse, delivered before the Historical Society of Mich 
gan, by Henry R. Schoolcraft.—This discourse contains very mag 
esting notices of the northern and interior portions of this continent, 
particularly in relation to the past and present condition of the abo- 
riginal tribes; and of their connexion with, and relation to the 
French, English and Anglo-Americans. A historical society, ¥ 
