Meteorology. 181 



When taken out it was rough and warm, with a strong sulphureous smell. 

 It weighed 18 lbs. 7 oz. The explosion and the noise were heard over an 

 extent of 50 miles square. At a distance of 25 miles from the place where 

 it fell, it caused a whole plantation to shake. Prof. Silliman's Journal, 

 vol. ix. p. 351. 



24. Hoarfrost on Iron rails. — Dr MacCulloch has observed that hoar 

 frost exhibits a particular arrangement upon iron railing. The minute 

 crystals were aggregated into pyramidal groups, and each pyramid stood 

 on all the four edges of the iron bar, and was equally inclined to the two 

 adjacent planes, to the common section of which it stood perpendicular. 

 The temperature was a little below freezing, and there was a moderate fog, 

 with a high barometer. Brande's Journal, No. 39, p. 40. 



2#. Mean height of the Barometer at the level of the Sea, — In 1799, M- 

 Humboldt found that the mean height of the barometer, at the level of 

 the sea at Cumana, was 758,59 millimetres at 37° of Fahrenheit. M. 

 Boussingault found the height to be 760,17 at La Guayra, and M. Arago 

 found it to be 760,85 at Paris. 



26. Rainwithout Clouds. — On the 5th September 1799, at 3 o'clock p. m. 

 M. Humboldt saw large drops of rain fall at Cumana, when the sky was 

 quite blue, and without the slightest trace of clouds. 



27. Fall of Meteoric Stones in Italy. — In January 1824, between 9 and 

 10 h p. m., meteoric stones fell in the commune of Renalzo, twenty-one 

 miles from Cento. Their fall was preceded by a bright light, by three 

 loud explosions like the noise of cannon, which were heard over an extent 

 of several miles, and by a confused noise, like that of a number of bells. 

 The pheno-nenon lasted 20 minutes. Three stones were found, one of 

 which weighed 14 lbs. Bull, des Se. Phys. September 1825, p. 183. 



28. Baron Krusenstern s opinion ofMrAdie's Sympiesometer.— As we 

 had the good fortune to give the first account of this ingenious instrument, 

 invented by Mr Adie of Edinburgh, we are happy to be able to lay before 

 our readers the opinion of such a competent judge as Baron Admiral Kru- 

 senstern, the celebrated Russian navigator, who thus speaks of it in his 

 new memoirs, p. 47 : — " Although the marine barometer is generally con- 

 sidered as one of the most important instruments in navigation, yet the 

 commanders of vessels have not always the means of providing themselves 

 with one of them, as its price is so high as 12 guineas. But its place may 

 be supplied by the Sympiesometer, an instrument invented some years ago 

 by Mr Adie, a skilful optician in Edinburgh, which will be found of great 

 utility, even when there is a barometer on board the ship." After giving 

 an account of the principle of construction of the instrument, Baron Kru- 

 senstern adds : " it is therefore to be presumed, that this intrument which 

 is recommended by its moderate price, by its occupying little space, and 

 by its not being affected by the rolling of the vessel, will be particularly use- 



