1878.] Notices of Books. 40 7 
Harmonics, Consonance, Quality; Concord and Discord, and 
Resultant Tones. 
The last chapter, on Scale and Temperament, gives an account 
of several contrivances, all more or less elaborate, having for 
their object the perfeCt tuning of keyed instruments. It is to be 
feared that these complex key-boards offer such obstacles to 
freedom of execution as to be useless for all practical purposes. 
Dr. Stone’s remarks on tuning an orchestra are admirable, and 
will be read to advantage by every instrumentalist, many of 
whom, as conductors know too well, are extremely loose in their 
ideas of accuracy. 
A page at the end of the little book is devoted to the biblio- 
graphy of the subjedt, and will greatly aid the student in 
extending his researches. 
Studies in Spectrum Analysis. By J. Norman Lockyer, F.R.S. 
Second Edition. London : C. Kegan Paul and Co., 
1, Paternoster Row. 1878. 
Mr. Norman Lockyer’s present volume forms part of Messrs. 
Paul’s excellent International Scientific Series, and is written 
for the perusal of the more serious portion of the reading public, 
as well as for the more purely scientific student. Beginning 
with the vibrations of a jerked rope, the author explains, in a 
singularly clear and homely manner, the phenomena connected 
with wave-motion, the illustrations employed by him being of a 
nature which will be understood by every observant person. He 
shows that the principles upon which all undulations are produced 
— whether they are caused by muscular force, sound, heat, light 
or electricity — are similar, if not identical, a point which is only 
too frequently lost sight of by writers and lecturers on popular 
science. If, by setting forth the relationship between a note in 
music and a bright line in the speCtrum, a thoughtful reader or 
leCturer can by analogy be made to see how the effeCts of a 
change in the rate of the wave-motion of the luminiferous ether 
as affeCting colours are brought about, a great point is gained. 
We believe Prof. Barrett, in his leCtures on the Connection be- 
tween Light and Sound, was one of the first to break ground in 
this direction : and the faCt that light is nothing more than an 
excessively fine kind of sound, the effeCts of which were per- 
ceived by the eye instead of the ear, was a revelation to the 
majority of his hearers. Mr. Lockyer treats of sound, light, 
heat, and electricity concurrently as being parts of one grand 
system of wave-motion, and we should be pleased to see his 
example followed by writers on elementary science who only are 
too fond of separating these subjects by hard-and-fast line s 
instead of treating them correlatively. 
