Horticulture. Gl 



mouth of the pipe, at an angle of 45°, the phaenoinena are no longer iden- 

 tical, but reversed. 



AA^ith this inclination of the fork, let it be moved parallel to itself and 

 over the mouth, as before, and now the sound will be the loudest when the 

 fork is vertical to tlie circumferential tangent, will decrease by approaching 

 the centre, and when there, will be inaudiblej being the converse of the 

 former.* 



3. T\\e branches of a tuning fork move simultaneously in opposite di- 

 rections ; and as each becomes the focus of a system of undulse, it follows 

 that the waves, having opposite phases of motion, must interfere ; and as 

 a consequence, the sound, which each limb would yield, if vibrating in- 

 dependently, must in the existing condition, be diminished. 



With a view to prevent such counteraction, I held a fork in my hand ; 

 and whilst vibrating, scarcely audibly, I thrust one of its limbs into a card- 

 board tube, and found my expectation realised in the increased intensity of 

 the sound. 



Hence, when a fork is held in the air, not touching a table or other 

 reciprocating surface, oue of its parts gives a louder sound than both 

 together. 



Also the compound sound from two unison strings has a less power on 

 the ear than the sum of their separate sounds, provided they be excited to 

 motion, so as to move in opposition in the same plane. 



Kensington, Jan. 1st, 1835. 



* Neither the foregoing phenomena, nor another which I described before the 

 British Association, at Edinburgh, can, perliaps, be satisfactorily explained until we 

 are better acquainted with the theory of the tuning fork. And " the mathematical 

 theory of the jtulses it generates is (even in the estimation of Sir John Herschel) 

 of the utmost complication, and of too high a nature to have a place in the En- 

 cyclopaedia Metronolitana." — Sound, art. liy. 



HORTICULTURE.* 



Amaryllis Striatifolia Concinna, as we have named it, is a new 

 variety, and the first which has bloomed out of a number of young seed- 

 lings presented to Mr. Miller in tiie spring of 1833, by the Rev. Dr. Swete, 

 of Redland, who is a very successful cultivator of this truly magnificent 

 family of plants. The seed was saved by Dr. Swcte in September, 1832, 

 from umarijll'is scmperjlorens, fertilized with tiie pollen of amarijllh auperha, 

 and the plant whicii has now, for the first time at the Bristol Nursery, 

 opened into bloom, is a splendid and distinct variety ; it has a fine head of 

 flowers of a bright rosy-red colour, with a broad white stripe extending 

 from the base to the point of each petal, and is very finely scented, like 



• We arc iudebted for tills Notice, from the gardens of Mr. Miller, to Mr. M. Mayes, 

 by whom the observations are made. — Kd. 



