VOL. XLI.] PHILOSOPHICAL TRANSACTIONS. 413 



Of an Extraordinary Exostosis on the Back of a Boy. By Mr. John 

 Freeke, F. R.S. N° 456, p. 369. 



There came to St. Bartholomew's Hospital a boy of a healthy look, and 

 about 14 years old, to ask. what should be done to cure him of many large 

 swellings on his back, which began about 3 years since, and had continued to 

 grow as large on many parts as a penny-loaf, particularly on the left side. 

 They arose from all the vetebrae of the neck, and reached down to the os 

 sacrum ; they likewise arose from every rib of his body, and joining together 

 in all parts of his back, as the ramifications of coral do, they made, as it were, 

 a fixed bony pair of bodice. Mr. F. considered this as an extraordinary case of 

 exostosis. It is added that the boy had no other symptoms of the rickets on any 

 joint of his limbs. 



An Account, by John Eames, F. R. S. of a Dissertation, containing Remarks on 

 the Observations made in France, to ascertain the Figure of the Earth, by Mr. 

 Celsius, entitled, De Observationibus pro Figura Telluris determinanda, in 

 Gallia habitis, Disquisitio. Auct. And Celsio, Upsal, 1738, 4to. N°. 457, 

 p. 371- 



That the figure of the earth is spheroidical is agreed on by all : but whether 

 it be an oblong or oblate spheroid, i. e. whether the axis be longer or shorter 

 than a diameter at the equator, has been for some time a matter of doubt. 

 Three several methods have been proposed to determine this controversy by ex- 

 periments ; as, by the different lengths of pendulums vibrating seconds, in dif- 

 ferent latitudes ; by the figure of the earth's shadow in lunar eclipses; and by 

 the actual measurement of the lengths of a degree on the meridian in different 

 latitudes. 



It is certain, if the lengths of the degrees of latitude decrease as we go from 

 the equator towards the poles, then the axis is greater, and the figure an ob- 

 long spheroid; but, on the contrary, if these lengths increase as we remove 

 towards the poles, the axis is less than s diameter at the equator, and conse- 

 quently an oblate spheroid. 



Mr. Cassini and others, judge the earth to be of an oblong spheroidical figure; 

 and the observations made in France, if entirely to be depended on, prove 

 this hypothesis to be a matter of fact. Our late illustrious president. Sir Isaac 

 Newton, Mr. Huygens, and others, make the earth to be an oblate spheroid, 

 higher at the equator than at the poles ; and this figure of the earth is undoubt- 

 edly the true one, if the observations lately made near the arctic circle be ad- 

 mitted as certain and exact. So that since both sets of observations have been 



