450 



Intelligence and Miscellaneous Articles. 



leading to the formula (FeO CuO)S05 4- 7H0, which represents 

 common sulphate of iron in which a portion of the iron has heen 

 replaced by copper. — Comptes Rendus, April 18, 1859. 



ON PROF. C. p. SMYTH S TENERIFFE METEOROLOGICAL OBSER- 

 VATIONS. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 

 The TenerifFe Astronomical Experiment (Phil. Trans. 1858) 

 somewhat confirms, in p. 513, my suggestion of meteorological 

 observations at six-hourly intervals (Phil. Mag. in June and July 

 1842, and post). Thus in Table I. the sums of 6, ; 7, 1 ; &c. 

 hours A.M. and p.m., and quadruple maximum difference from diur- 

 nal mean, are — 



exhibiting the nearly periodic form of these variations. 



In page 525, column 1, is " 5448" correct, as this height does 

 not harmonize with the succession of the other heights ? 



The fact of the summer maximum temperature occurring later in 

 the year as the mountain is descended (see pp. 517-531), induces 

 me to refer to a paper of mine epitomized in the Proceedings of the 

 Royal Society for March 3, 1842, wherein I compared the thermal 

 theory to the tidal one, proposed the mean heat at a given place 

 on a given day to be proportional to the sun's meridian altitude at 

 the same place on a day previous to the one inquired after, which 

 interval I termed " thermal establishment " of the place. Thus the 

 mer. alt. at the solstice would give the heat at the place of observa- 

 tion from 25 to 30 days afterwards, owing to the local causes of per- 

 turbation. These perturbing causes, according to Prof. Smyth, seem 

 to diminish as we ascend ; and in the free regions of upper air, the 

 maximum would j^robably then occur on the day of the solstice itself. 



S. M. Drach. 



Chelsea, May 16, 1859. 



