326 Mr. Ha worth's Seventh Decade of new Succulent Plants. 



objections. But we have his own authority at p. 359, founded 

 upon a more extensive comparison of facts, that the equatorial 

 pendulum is 39*01, and not 39*0156; and this new length 

 being combined with the northern experiments, will bring out 

 an ellipticity about '00326, the same with that generally re- 

 ceived. As the mean quantity 39*01 is fixed and determinate, 

 the natural conclusion seems to be, that *00326, which depends 

 upon it, is the ellipticity to be adopted in preference to *00346, 

 which is derived only from certain particular combinations of 

 the experiments, and varies when they are combined in a dif- 

 ferent manner. 



But the truth is, that Captain Sabine's tropical experiments 

 are inconsistent among themselves, and with all the good ex- 

 periments of other observers. In the present state of our 

 knowledge, five of them, or at least four, can be considered 

 only as anomalies which do not belong to the mean figure of the 

 earth. The irregularities are very great and apparent on in- 

 spection. Maranham and St. Thomas may be both reckoned 

 on the equator, the small differences of latitude hardly affect- 

 ing the length of the pendulum : ftow if a pendulum that beats 

 seconds at Maranham be transported to St. Thomas, it must 

 be lengthened 7n 8 6 M of an inch in order to oscillate in the 

 same time ; and if it were carried to the pole, its length must 

 be increased not so much as $$$$ f° r the same purpose. 

 Thus there is a local irregularity between Maranham and St. 

 Thomas, amounting to ^ of the whole increase of gravity 

 from the equator to the pole. It must be acknowledged 

 that when it shall be indisputably proved that inequalities so 

 great take place in the distribution of gravity, we can hope to 

 gain little in point of accuracy by employing the pendulum 

 for investigating the figure of the earth. 



Nov. 6, 1826. J. Ivory. 



[A continuation of this Paper, received while the present sheet was in the 

 press, will be given in a subsequent part of this Number.— Edit] 



XLVIII. Decas septima novarum Plantarum Succulentarum ; 

 Autore A. H. Haworth, Soc. Linn. Lond. — Soc. Horticult. 

 Lond. — necnon Soc. Cces. Nat. Cur. Mosc. Socio, tyc. fyc. 

 To the Editor of the Philosophical Magazine and Journal. 



Dear Sir, 

 HPHE seventh Decade of my new Succulent Plants being 

 ■*■ now completed, allow me to request that it may be ad- 

 mitted into an early Number of your interesting Magazine 

 and Journal. 



It is composed entirely of new and unrecorded species of 



Mesem- 



