42 Dr Heineken on the Sirocco Winds at FunchaL 



ter, when the doors of the house were closed, — had it been the 

 reverse, — had my mean been higher than that obtained by the 

 v^ual method^ — I should at once, and without a word in its sup- 

 port, have given it up. I believe that the means given for 

 all low latitudes are considerably too high^ — that, (as I have 

 said before,) there is only one method of arriving at the truths 

 namely, by observations made on several instruments, and in 

 various situations ; and if it be not pushing the matter too 

 far, I could almost think it more probable that maxima ob- 

 servations made in the mode in which mine were made would 

 be proved too high, rather than too low, by this criterion, — as- 

 suming, be it remembered, that positive and artificial shade 

 is implied by the terms, " shade maxima," and that a true mean 

 temperature can be obtained by such shade only. 



I shall endeavour throughout the current year to make the 

 ten oVlock morning and evening observations, and those also 

 regarding wells, which the Editor was kind enough to suggest 

 in the last number of this Jmirnal; and I am also daily expecting 

 a couple of maximum thermometers from England, which I have 

 directed to be made to correspond accurately, and which I in- 

 tend to place — the one, in what appears to be the most perfect ex- 

 ternal shade, throughout the four-and-twenty hours which the 

 situation admits, — and the other in the same situation in which 

 my internal maximum instrument now hangs. I hope then, that, 

 between the three modes, we shall succeed in obtaining a truer 

 mean than has yet been given for the temperature of this place. 



FuNCHAL, Madeira, 10th February 1829. 



Art. VI — Account of the Sirocco Winds at Funchal, in the 

 Island of Madeira, during the years 1826, 1827, and 1828. 

 By C. Heineken, M. D. Communicated by the Author. 



The following observations were made during the prevalence 

 of the Sirocco winds in 1826, 1827, and 1828. 



