4b0 Scientific Intelligence. — Meteorology. 



Extreme Cold and Heat by Six's Thermometer. 



Coldest, 3d January Wind SW. 18° 



Hottest, 16th July, SW. ^b 



Mean Temperature for 1827, 48 255 



Result of Two Rain Gauges. 



1. Centre of Kinfauns Garden, about 20 feet above the level of the inches. 



Sea, .... - 34.90 



2. Square Tower, Kinfauns Castle, about 140 feet, - 35.60 



6. Mr Watt's Solar and Lunar Compasses. — Mr Watt ha- 

 ving observed that the forms of the solar compass, which were 

 described in a preceding number of this Journal, although they 

 exhibited well the phenomena mentioned from the vernal to the 

 autumnal equinox, yet did not move so readily when the sun's 

 declination became greater, finds that the motions become very 

 distinct, by adopting the following improvement. Stretch a 

 circulcU* disc of dark-coloured velvet, of about four inches dia- 

 meter, upon two very thin slips of light wood, or upon two fea- 

 thers, placed across each other at right angles ; render about 

 S5 grains weight of pure filings of steel magnetic, by putting 

 them between the folds of a piece of paper, and drawing the 

 ends of two magnets about thirty times across them. Rub the 

 filings over the whole face of the velvet disc, they will then sink 

 into the spaces formed by the piles of the silk. Let this be af- 

 fixed to the end of a very light bar of wood, or to the opaque 

 part of a writing quill, four inches long, by a fine needle passed 

 through the disc : make a small perforation in the wood or quill, 

 at tlie distance of one-third of its length, measuring from the 

 point to which the disc is attached : press a small agate or glass 

 capsule into the aperture : without any wax or fixture, the elas- 

 ticity of the wood or quill keeps it sufficiently firm : balance it 

 on a fine steel point, and let the cover be put over it. This in- 

 strument moves to the influence of the solar beam from morn- 

 ing to evening, on our shortest days, even when the thermometer 

 stands at freezing, and though the rays fall upon it through the 

 glass of a window and the glass of the cover: — and the motion 

 of the balancing bar is as slow, equal, and constant, when the 

 sky is clear, as the shadow of the gnomon of a dial. — Mr Watt 

 has also observed, that this instrument, and several other bodies, 

 clearly indicate by their motion the attractive influence of the 

 lunar beam. An account of the experiments, directed to ascer- 



