TOL. IV.] PHILOSOPHICAL TRANSACTIONS. 340 



watches should stop, yet you may at any place, whereof the longitude is cer- 

 tainly known, make them go on again, and adjust them there by the sun, and 

 so reckon the longitudes from that meridian. 



12. If all the watches should stop at sea, you must, as speedily as possible, 

 set them going again, that you may know how much you advance from that 

 place towards the east or west; which is of no small importance, since, for want 

 of this knowledge, you are sometimes by the force of currents so carried away, 

 that though you sail before the wind, yet you are driven a-stern, of which there 

 are many instances. 



Extract of a Letter, written by Dr. Edjvard Brown from Vienna, 

 concerning two Parhelias or Mock Su?is, lately seen in Hungary, 

 N' 47, p- 953. 



I received the account of the parhelias seen January 30, 1669, N. S. about 

 one o'clock in the afternoon, over the city of Cassovia in Hungary. It was 

 communicated to me from a learned Jesuit, called Father Michel, now in this . 

 city. There were two parhelias, one on each side of the true sun, and they 

 were so resplendent, that the naked eye could not bear their brightness. The 

 lesser began to decay before the other, and then the other grew larger, and 

 continued near two hours, projecting very long rays from it. On that side 

 next the sun, they were tinged with a pale yellow; the other parts being some- 

 what obscure. There were at the same time seen several rainbows, with the 

 segment of a large white circle, of a long duration, passing through the two 

 parhelias and the sun, and all this at a time when the air was almost free from 

 clouds, though here and there some very thin ones were scattered. 



Of the Conferences held at Paris in the Royal Academy for the Im- 

 provement of the Arts of Painting and Sculpture. N" 47, p- 953. 



These conferences are held once in a month by several able masters, mak- 

 ing reflections and observations on the rarest pieces in the king's cabinet. M. 

 Colbert, who takes a very particular care to make arts flourish in France, being 

 to visit those artists some time since, and having received an account of what had 

 been done in their meetings, expressed himself to this effect; that as it was ne- 

 cessary for the teaching of arts, to join examples to precepts ; so he thought it 

 proper that, from time to time, the works of the most excellent painters should 

 be examined, and such observations made on them, as would inform others, 

 wherein the perfection of a picture consists. Which has been ever since prac- 

 tised among them, as the best means to carry the art of painting to its highest 



