MEETING OF THE BRITISH ASSOCIATION. 127 



in the parish of Alderley ; and Dr. Kead on a book which he is 

 bringing through the press, proposing a new plan for the extension 

 of physical science. 



It having been arranged that no lecture would take place on 

 Thursday evening at the Rotundo, the round room and gardens 

 were opened for an evening promenade, which was most fashiona- 

 bly and numerously attended. Most of the savans in town enjoyed 

 this opportunity of social intercourse with the Irish people. The 

 gardens were brilliantly illuminated, and the fine bands of the 7th 

 Dragoons and the 14th regiment played alternately several of the 

 choicest musical compositions. 



Friday. — The sections did not assemble until twelve o'clock, in 

 consequence of the fete at the Botanic Gardens. 



Section A. — Mathematics and Physics. — Professor Apjohn made 

 a communication on the determination of the dew point. He esta- 

 blished his plan by experiments so clearly, that it is likely to become 

 the general hygrometrical instrument used by philosophers. — A 

 memoir of Professor Challies on the simultaneous vibration of 

 cylindrical tubes, and the air contained in them, was read by 

 Professor Hamilton, as secretary of the section, in his most im- 

 pressive style. — Professor Wheatstone made a communication on the 

 various mechanical constructions to imitate the human voice ; he ex- 

 hibited an instrument composed of a sound box, with a bellows at- 

 tached to one end, to the other the frustrum of a cone, with the base 

 outside, and keys inside the box, to the other end ; by pressing the 

 wind through the bellows, and fingering the keys with one hand, 

 the other being applied to the box of the frustrum of the cone, and 

 was thus enabled to utter intelligibly the words '^ papa," '^' mamma," 

 *^ thumb," *^ plumb." — Professor Whewell brought forward his mo- 

 del of a new anemometer, which was ingeniousl}'" contrived, not 

 only to shew the direction of the wind, but also its intensity, with 

 a view to the correct ascertainment of the quantity of disturbance, 

 in any given time, in the superincumbent air. The machine is also 

 self-registering, by means of a spring pencil acting upon a cylinder. 

 The contrivance seems exceedingly simple, and is considered likely 

 to lead to some definite and practical results. — Captain Sir John 

 Ross alluded to the means adopted by him during his last voyage, 

 to register the direction of the winds, their velocity, combined with 

 the state of the weather, the barometer and thermometer, from ob- 

 servations as accurately made as circumstances would admit of, every 

 half hour. He expressed his doubt of the utility of the instrument 

 in the arctic regions, but said he would have wished to have had 

 such an instrument with him on his last voyage as the one then sub- 

 mitted, in order to test its utility and accuracy. — Professor Lloyd 

 mentioned the result of several observations entered into by him and 

 Captain Sabine on the dip and variation of the needle in various 

 parts of Ireland. They were desirous, in their observations, to as- 

 certain, with accuracy, the intensity of the terrestrial magnitude : 

 these observations were undertaken as a part of a considerable num- 



