JMiscellanies. 359 
to Edw. Cooper, M. P. an instrument of twelve and a half inches 
aperture. -These are the two largest achromatics which exist. 
The first already proved by a great number of Astronomers, appears 
to be an excellent instrument, and M. Cauchoix hopes that the other 
will not be less satisfactory. He has just finished a new telescope, 
similar to Mr. South’s, whose aperture is eleven.inches fr. and fo- 
cal distance eighteen feet. The effect of this instrument appears 
still better, the images’ more neat, the materials exempt from all 
threads and strie. He has also ready for delivery an excellent instru- 
ment of eight anda quarter inches diameter, and twelve feet focus, 
and he also has object glasses of seven and a half, seven, six and a 
half, six, &c. The flint glass of all these object glasses is we be- 
lieve of the manufacture of M. Guinand. . 
M. Cauchoix has constructed object glasses in which the crown 
glass is replaced by rock crystal, and which have the advantage of 
greater amplifying power, joined to a less focal distance. He possess- 
es three of “fifty nine lines diameter, and fifty inches focal distance, 
and he thinks, from the difficulty he has found for the last four years 
in procuring disks of this diameter, of sufficient purity, that others 
of these dimensions can scarcely be obtained. 
On account of ill health, M. Cauchoix, is about to relinquish his 
establishment, to his nephew, who unites much solid information to 
the experience derived from his uncle..—Bub. Univ. Sep. 1831. 
* 15. Preservation of plants during winter by spring water—A 
horticulturist.in Scotland has availed himself of the heat of spring 
water, in the preservation of-delicate plants. He places boxes of 
pine wood over the water, covering them with some coarse stuff, and 
in these boxes he places pots of cauliflowers, lettuce, various sorts of 
pelargoniums, Indian chrysanthemums, Chinese primroses, &c. and 
by this simple and economical method, preserves them all winter, 
He is of opinion that by means of the temperature of running water, 
winter gardens may be constructed for a farm or village. Care must 
be taken to renew the air in the boxes.—Jdem. 
16. French premiums.—The following prizes are offered by the 
-French Society for the Encouragement of National Industry, one 
half-of the funds being furnished by the minister of trade and pub- 
lic works, ia) 
