On a new Kite- Apparatus for Meteorological Observations. 191 



the law of oddness and evenness, to which the coefficients of 

 the given equation are in the first theorem generally (in order 

 for the successful application of my method as far as it is yet 

 developed) required to be subject. I stated this law erro- 

 neously, and consequently drew erroneous conclusions from 

 my Theorems of Transformation, which I am very anxious 

 to seize the earliest opportunity of correcting. I venture to 

 flatter myself that as opening out a new field in connexion 

 with Fermat's renowned Last ' Theorem, and as breaking 

 ground in the solution of equations of the thii'd degree, these 

 results will be generally allowed to constitute an important 

 and substantial accession to our knowledge of the Theory of 

 Numbers. 

 26 Lincoln's Inn Fields, 

 August 24, 1847. 



XXXIV. Experiment made at the Kew Observatory on a new 

 Kite- Apparatus for Meteorological Observations^ or other 

 purposes^, 



MR. W. R. BIRT (on the Uth of this month) took some 

 kites, &c. to the Kew Observatory, for the purpose of 

 endeavouring to ascertain how far it might be practicable to 

 measure the force of wind at various elevations by their means, 

 and (in the mere manipulation of his experiments) was assisted 

 by Mr. Ronalds. After several trials, &c. they agreed that 

 the sudden variations, horizontal and vertical, in the position 

 of the kite, the great difficulty of making a kite which should 

 present and preserve a tolerable approximation to a plane, 

 that of measuring, with sufficient accuracy, at any required 

 moment, its inclination, and lastly, the influence of the tail, 

 would always tend to render the observation somewhat unsa- 

 tisfactory. Mr. Ronalds then proposed to try the following 

 method of retaining a kite in a quasi invariable given position. 

 Three cords were attached to an excellent hexagonal kite of 

 Mr. Dirt's construction : one in the usual manner, and one 

 on each side (or wing). The kite was then raised as usual ; 

 the two lateral cords were hauled downward by persons stand- 

 ing at the apices of a large equilateral triangle (described upon 

 the ground) until the ascending tendency became considerable 

 (even when the force of the wind was at its minimum), and the 

 three cords were made fast to stakes or held in the hand. 

 He had entertained no expectation of the favourable result of 

 this simple and obvious contrivance. 1 he place of the kite 

 did not seem to vary so much as one foot in any direction, and 

 it really appears to him probable that a very large kite or 

 kites might be employed in this kind of manner often and very 

 * Comraunicated by Mr. Ronalds. 



