VOL. LII.3 I'lIILOSOPHICAL TRANSACTIONS. 543 



from his elbow to the wrist seem to be one solid bone. It is very happy for him 

 that it has been hitherto stopped fronj proceeding any farther; and that from his 

 present state of good health, there is reason to hope that it will not increase. 



XXIX. Description of a new Thermometer and Barometer. By Keane Fitz- 



gerald, Esq., F.R.S. p. 146. 



Mr. F. lately communicated a paper, with an account of an instrument, in- 

 tended to answer in some measure the purposes of a thermometer and pyrometer. 

 The degrees the index had pointed to, during the absence of an observer, were 

 marked by a pencil applied to it. But he found great inconvenience from the 

 friction of the pencil, which must be strong, or it does not mark distinctly ; be- 

 sides the trouble of rubbing out the mark, every time a new observation was in- 

 tended. He now offers the description of an instrument on the same principle 

 as a thermometer only, with registers to mark the least variation that can happen 

 during the absence of an observer; but too complex to be useful. 



XXX. Of the Earthquake* felt in the Island of Madeira, March 31, 1761. 



Bij Thomas Heberden, M. D., F. R. S. p. 155. 



In the city of Funchal, on the island of Madeira, March 31, 1761, they 

 were alarmed with the shock of an earthquake, preceded by the usual noise in 

 the atmosphere, like heavy carnages passing hastily over rough pavements. It 

 began at 35 minutes after 1 1 o'clock in the morning, and lasted, by the watch, 

 full 3 minutes ; the vibrations, which were very quick, remitting and increasing 

 twice very sensibly during the shocks, which seemed to be progressive, from east 

 to west. It has separated some rocks in the eastern part of the island, which 

 have fallen from the cliffs into the sea. It has likewise damaged the walls of 

 several buildings; particularly such walls as stand in a direction north and south. 



During the earthquake the fountain of the city, the water of which is very 

 clear at other times, ran turbid and whitish. The sea was agitated very sensibly, 

 fluctuating several times between high-water and low-water mark. The fluctua 

 tion of the sea continued longer in the eastern parts of the island than in this 

 part. The sun, which shone very bright before, immediately after the earth- 

 quake was surrounded by a very large halo, which lasted about an hour, and 

 gradually disappeared. .f 



XXXI. j4n Account of a Treatise in Latin, presented to the Royal Society, en- 

 titled De Admirando Frigore Artifciali, quo Mercurius est Congelatus, Dis- 



* See the account of the same earthquake felt at Lisboiij p, 541, 



