40 On Mr. 'Arthur IFoolfs improved Apparatus, 



My second ascent of the peak was not only a lesson : it 

 furnished me, as well as my researches respecting an erup- 

 tion which took "place in 1 705 at Guiniar, with a number 

 of tacts, of which I \\ ish I were able to give you an ac- 

 count. But I must be contented with assuring you that 

 few of my journeys have aftbrded me so much satisfaction 

 as the present. I had every assistance and aid I could de- 

 sire, both from individuals and from the Spanish govern- 

 ment. I shall never forget the reception I met with from 

 the marquis de Perlasca, the governor-general of the islands; 

 and from the marquis de Casa Cajigal, who commands under 

 him. 



V. Qn Mr. Arthur Woolf's 'improved Apparatus, ap- 

 plicable to Steatn Engines and other Purposes of Art and 

 Manufacture : including a Description of two Boilers now 

 . erecting qt Messrs. Meux's Brewery. 



J\jLr. Wqolf's improved apparatus consists, First, of two 

 or more cylindrical vessels properly connected together, and 

 so disposed as to constitute a strong and fit receptacle for 

 watcr,or any other fluid intended to be converted into steam, 

 whether at the usual heats or at temperatures and under pres- 

 sures uncommonly high ; and also to present an extensive 

 portion of convex surface to the current of flame, or heated 

 air or vapour from a fire : Secondly, of other cylindrical 

 receptacles placed aboye these cylinders, and properly con-, 

 nected with them, for the purpose of containing water and 

 steam, and for the reception, transmission, and useful ap- 

 plication of the steam generated from the heated water or 

 other fluid : and. Thirdly, of a furnace so adapted to the 

 cylindrical parts just mentioned, as to cause the greater part 

 of the surface of all and each of them, or as much of the 

 said surface as may be convenient or desirable, to receive 

 the direct action of the fire, or heated air and vapour. 



That our readers may be able fully to comprehend the 

 way in which Mr. Woolf constructs his apparatus, we shall 

 present some plans and views, with such a description as 

 Avill, we hope, convey a pretty correct idea of their nature. 



Fig. 1. (Plate 1.) represents one of his boilers in its most 



simple form. It consists of eight lubes marked a, made ot 



cast iron or any other fit metal, which are each coniiected 



\yith the cylinder A placed above them, as Shown in the 



jide view fig. 2, in which the same letters refer, to the same 



parts 



