Mr. Haworth's Description ofnetsi Succulent Plants. '2.1 \ 



cessary and desirable, (if it can possibly be obtained,) that I 

 embrace this opportunity of suggesting what I consider the 

 most likely means of ascertaining this important object. 



I recommend the employment of a machine that has not 

 hitherto been of the least use in promoting a knowledge of 

 either the arts or sciences, although numerous adventurous 

 individuals have perished in the attempt to navigate it through 

 the aerial flood, to gratify the idle curiosity of countless mul- 

 titudes. 



If the dip be taken at the place from whence the balloon 

 is intended to ascend, and the same needle (which ought to 

 be of the most perfect construction) be carefully deposited in 

 the car attached to the balloon, any number of observations 

 may be recorded by the aeronaut or his companion, according 

 to the variation or decrease of the dip as the altitude of the 

 observers increases. It will be necessary, in order to insure 

 the accuracy of the experiment, to have a correct set of ap- 

 paratus, independent of the dipping-needle ; as a mountain 

 barometer, a thermometer, &c. to ascertain the altitude and 

 the temperature of the air at the moment when the dip is 

 taken at each observation. 



If during an aerial voyage the experimenters (for I consi- 

 der one person incapable of managing the balloon and makmg 

 the necessary observations) should be elevated only two or 

 three miles, they, I have not the least doubt, would observe 

 a diminution of magnetic action upon the needle, long before 

 they reached that elevation ; or its influence will extend far 

 beyond our atmosphere : and if the distance of two or three 

 miles from the earth's surface would only afford us two or 

 three very minute and progressive variations in the dip, we 

 might be enabled thereby to solve many curious problems in 

 magnetism.* 



Holy Green House, Sheffield, Feb. 9, 1827. 



LVI. Description of Ne',Si Succulent Plants. By A. H. Ha- 

 woRTH, Esq. F.L.S. 8)C. 



IN this my ninth Decade of new Succulent Plants, are de- 

 scribed ten South- African species ; the first five of which 

 were discovered near the Cape of Good Hope, and sent from 

 thence to the royal gardens of Kew, by Mr. Bowie, where 



♦ An experiment on this sul)ject in which the ilij) appeared to he reversed 

 at the cleviition of about HOOO feet, was made by Sacharof and Robertson 

 during their aerial voyage from St. Petersburgh, on the 30tli of January 

 1804, See Hliil. Mag. vol. xxi. p. lyii.— Emx. 



they 



