390 Horticultural Society. 



them could observe the immersion) was rendered sensibly 

 more obtuse, and at the instant after separation approximating 

 to a rectilinear boundary. At the emergence of the eastern 

 limb of the globe of Saturn a similar effect was observed by 

 Mr. Comfield, but not by Mr. Wallis. 



A paper was next read On the determination of latitudes 

 by observations of azimuths and altitudes alone, by M. Lit- 

 trow, Assoc. Ast. Soc. This paper includes the consideration 

 of four cases. In the 1st, the latitude is computed from the 

 observed azimuth and altitude. In the 2d, two observed alti- 

 tudes are taken, and the two instrumental azimuths at the 

 same respective moments ; and the latitude is found from the 

 corrected altitudes, and the difference of the azimuths, with 

 the addition of an approximate latitude. In the 3d case, three 

 observed latitudes, and three corresponding azimuths, or two 

 azimuthal differences, are required ; and the latitude is thence 

 detennined. In a tth case, the problem is solved by means 

 of a watch instead of an azimuth circle ; there are supposed 

 given, the time of culmination only within half or three-quar- 

 ters of an hour, three altitudes taken within that distance of 

 the meridian, and their intervals in time ; to find the true lati- 

 tude. The solutions to all the four cases are exceedingly sim- 

 ple, and the resulting formulae admit of the utmost facility of 

 application. 



Lastly, there was exhibited to the Society a model of one 

 of the large reflecting telescopes made by Mr. John Ramage, 

 of Aberdeen, and of the stands, frame, and mechanism 

 for facihtating its motions and adjustments. The reading of 

 a descriptive paper, by Mr. Ramage, was also commenced ; but 

 its termination was postponed until the December meeting. 



HORTICULTURAL SOCIETY. 



Aug. 16. — The large silver medal was presented to Mr. 

 William Greenshields, a Corresponding Member of the So- 

 ciety, gardener to Richard Benyon de Beau voir, Esq. F.H.S., 

 for a communication on the cultivation of the pine-apple, 

 which is printed in the Transactions of the Society. — The 

 following paper was read : On the management of Amaryllis 

 vittata in the open air, by Mr. John Brown, gardener to 

 Chandos Leigh, Esq. F.H.S., at Stoneleigh Abbey. 



Oct. 4. — The following paper was read : On the culti- 

 vation of the large varieties of French melons, by the Rev. 

 J. Le Sene. 



Oct. 18. — The following papers were read : On the cultiva- 

 tion of the Passiflm-a quadraiigularis, by Mr. John Mitcheson. 

 — On the means of obtaining an abundant second crop of me- 

 lons, by Mr. Charles Harrison, F.H.S. 



