397 



in London, in a mean solar day, he finds to be 67*12, from which it 

 results that the compression of the earth is -rrr.r- 



The author is of opinion that the invariable pendulum ought to be 

 a standard instrument in every observatory ; that it should be swung 

 at all seasons of the year, and occasionally transferred to various 

 fixed observatories in both hemispheres, and returned again to its ori- 

 ginal station, where it should undergo a renewed and rigid exami- 

 nation before it is sent round on a fresh circuit of these stations. 



To this paper a note is subjoined by Capt. Sabine, containing a 

 correction of the result obtained by Mr. Fallows, resulting from the 

 application of the true elements of reduction for buoyancy and ex- 

 pansion, as stated in his late paper in the Philosophical Transactions, 

 which had not reached the Cape when Mr. Fallows made his com- 

 putations. The result of this correction gives 67*15 vibrations instead 

 of 67*12. But when the observations of Capt. Ronald in London are 

 taken in conjunction with those of Capt. Sabine, the retardation at 

 the Cape is brought back to the exact number stated by Mr. Fallows. 



Statement of the principal Circumstances respecting the united Siamese 

 Twins now exhibiting in London. By George Buckley Bolton, Esq. 

 Member of the Royal College of Surgeons, and of the Medical and 

 Chirurgical Society of London. Communicated by the President. 

 Read April 1, 1830. [Phil. Trans. 1830, ;>. 177.] 



The twin brothers, of whom an account is given in this paper, were 

 born of Chinese parents in 1811, at a small village in Siam, distant 

 about sixty miles from Bankok, the capital of the kingdom. When 

 the intelligence of their birth had reached the ears of the King of 

 Siam, he gave orders that they should be destroyed, as portending 

 evil to his government ; but on being assured that they were harm- 

 less, and would be capable of supporting themselves by their own 

 labour, he changed his intention, and suffered them to live. About 

 six years ago Mr. Robert Hunter, a British merchant resident at 

 Siam, saw them, for the first time, in a fishing-boat on the river, in 

 the dusk of the evening, and mistook them for some strange animal. 

 It was only in the spring of last year that permission could be ob- 

 tained from the Siamese Government to bring them to England. They 

 were taken to Boston, in the United States, where they landed in 

 August last, and six weeks afterwards embarked for England, and 

 arrived in London in November. They are both of the same height, 

 namely, five feet two inches, and their united weight is 180 pounds. 

 They have not the broad and flat forehead so characteristic of the 

 Chinese race, but they resemble the lower class of the people of Can- 

 ton in the colour of their skins and the form of their features. Their 

 bodies and limbs are well made. The band of union is formed by the 

 prolongation and junction of the ensiform cartilages of each, which 

 meet in the middle of the upper part of the band, and form moveable 

 joints with each other, connected by ligamentous structures. Under- 



