SyS VHILOSOPHICAL TKANSACTIONS. [aNNO 1742. 



sities, among which was a great number of foreign seeds, and finding he had 

 inelon seeds that were laid up in a paper in the year 17OO ; Mr. T. was curious 

 to try if they had retained their vegetative quality, and accordingly the 21st of 

 Feb. 1741, he planted '24 of them in a separate hot-bed, from which he had 

 21 good plants, which, after they were planted in a new-made hot-bed, showed 

 flowers before they began to branch themselves, and their branches were very 

 narrow, yet produced early and plenty of good melons. This experiment shows 

 not only how very long melon seeds will retain their vegetative quality, but also 

 that good melon seeds cannot well be too old. It is no new thing to make use 

 of old melon seeds rather than new, but he has never heard of any person try- 

 ing so old as these. 



On the Differences of the Heights of Barometers. By M. Samuel Christian 

 Hollman, Leg. Met. and Theol. Natural, in Regia Georgia Augusta, P. P. O. 

 N° 464, p. 116. From the Latin. 



In July and Aug. 1741, M. Hollman made several observations with baro- 

 meters, in a visit he made to the mountains of Hercynia in Sweden. Having 

 prepared a new barometer for this purpose, he divided its scale of ascent and 

 descent into Rhinland inches and lines, or 12ths, from the 20th to the 32d 

 inch. On applying it to this barometer, and comparing it with 6 others, which 

 he hiid by him, he found that they all showed different heights of quicksilver, 

 the differences extending from 2 to 12 lines, the new one being 2 lines higher 

 than any of the others. 



On his return to Stockholm from the mountains, he compared the barometers 

 again, and finding still the same differences, he constructed several other new 

 ones, with upright tubes, of different apertures, atnong which he found also 

 differences of from 1 to 4 lines; those which rose the highest, exceeding one 

 which he called his best, by full 6 lines, or half an inch. 



Aug. 12 he repeated the experiments again with his 1 5 barometers, and find- 

 ing again nearly the same differences, he then prepared 10 other new ones, with 

 upright tubes, some of them having bent glass cisterns to hold the quicksilver, 

 and some without. Among these the 10 heights differed from 1 to I4- lines, 

 and they exceeded the height of his best barometer by 4 lines. 



These barometers were all made in the same manner, and great care was 

 taken to free the tubes and the quicksilver from all air. There was indeed some 

 difference in the glass of the tubes; the best barometer, in which the quick- 

 silver had always the least height, had its tube of green glass, with a separate 

 cistern made of the same glass; this barometer is N° 1 of class 1 following; 

 N° 2 being that which was used in the mountains of Hercynia. But that tube 



