do PHILOSOPHICAL TRANSACTIONS. [aNNO 1660. 



Mr. Boyle riding between Oxford and a lodging he had about four miles 

 from that town, in that short space of time, from a settled frost, the wind 

 turned and it began to rain. Soon after his getting home, he felt a manifest 

 trembling in the house, which stands high comparatively with Oxford. But 

 he should not hav^e taken notice of it as an earthquake, had it not been 

 perceived by the people of the house. Soon after there happened a brisk storm ; 

 on which he sent to make inquiry at a place called Brill, which standing higher 

 might be supposed more liable to the effects of the earthquake ; and he was in- 

 formed that it was very considerable there ; and that a gentleman's house in 

 the neighbourhood shook very much, so that the stones in the parlour mani- 

 festly moved to and fro. The hill on which this Brill stands, is stored with 

 mineral substances of several sorts. Mr. Boyle adds, that he has been told 

 that this earthquake reached a great many miles. 



Observations on tlie Barometer. By Dr. JVallis. N" 10, p. 166. 



The Doctor never observed the quicksilver higher than 30 inches, nor lower 

 than 28, at least within -^^ of an inch of these numbers, either over or under. 



In thick foggy weather, he found the quicksilver rise ; which he ascribes to 

 the heaviness of the vapours in the air. 



In sun-shiny weather it rises also, and commonly the clearer the weather the 

 higher it is ; which may be owing partly to the vapours raised by the sun and 

 increasing the weight of the air ; partly to the heat which adds to the elasticity 

 of the air ; which latter he mentions, because in sun-shiny weather, which be- 

 came afterwards cloudy for an hour or two, the quicksilver has fallen ; and then 

 on the sun's breaking out again, it has risen as before. 



In rainy weather it falls, because the air is light in proportion to the quantity 

 of vapours that falls ; and also in snowy weather, but not so much as in rain ; 

 and sometimes it has fallen upon a hoar-frost in the night. 



In windy weather it generally falls, and more discernibly than in rainy, ow- 

 ing possibly to the winds moving the air laterally ; and thereby preventing its 

 pressure downwards ; and he never found it lower than in high winds. 



He observed the quicksilver fall without any visible cause, but upon looking 

 abroad, he found it had rained at some distance ; whereby the heavier air might 

 have in part discharged itself on the lighter. 



The Rotation of Jupiter on his Axis. By Mr. Hook and M. Cassini. 

 N" 10, p. 171, and N' 82, p. 4039- 

 About nine o'clock at night. May Qth, anno l664, Mr. Hook observed, with 

 a good 12 foot telescope, a small spot in the largest of the three obscurer belts 



