SCIENTIFIC CATALOGUE. 



Airy (G. B.) continued. 



relating to chances which can be altered only by the changes of entire 

 units or integral multiples of units in the fundamental conditions 

 of the problem ; the other concerning those chances -which have 

 respect to insensible gradations in the value of the element measured), 

 this volume has been drawn up. It relates only to errors of observa- 

 tion, and to the rules, derivable from the consideration of these 

 errors, for the combination of the results of observations. 



UNDULATORY THEORY OF OPTICS. Designed for the Use 

 of Students in the University. New Edition. Crown 8vo. cloth. 

 6s. 6d. 



The undulatory theory of optics is presented to the reader as having 

 the same claims to his attention as the theory of gravitation, namely, 

 that it is certainly true, and that, by mathematical operations 

 of general elegance, it leads to results of great interest. This theory 

 explains with accuracy a vast variety of phenomena of the most 

 complicated kind. The plan of this tract has been to include those 

 phenomena only which admit of calculation, and the investigations 

 are applied only to phenomena which actually have been observed. 



ON SOUND AND ATMOSPHERIC VIBRATIONS. With 

 the Mathematical Elements of Music. Designed for the Use of 

 Students of the University. Second Edition, revised and enlarged. 

 Crown 8vo. 9-r. 



This volume consists of sections, which again are divided into num- 

 bered articles, on the following topics : General recognition of the 

 air as the medium which conveys sound ; Properties of the air on 

 which the formation and transmission of sound depend ; Theory of 

 undulations as applied to sound, etc. ; Investigation of the motion 

 of a wave of air through the atmosphere', Transmission of waves 

 of soniferous vibrations through different gases, solids, and fluids; 

 Experiments on the velocity of sound, etc. ; On musical sounds, 

 and the manner of producing them; On the elements of musical 

 harmony and melody, and of simple musical composition; On in- 

 strumental music; On the human organs of speech and hearing. 



A TREATISE ON MAGNETISM. Designed for the Use of 

 Students in the University. Crown 8vo. gs. 6d. 



As the laws of Magnetic Force have been experimentally examined, 



