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THE POPULAR SCIENCE MONTHLY. 



side and back to the point of rest. Reg- 

 ular and continuous vibrations produce 

 music ; irregular vibrations result in noise. 

 There are four laws or canons of the 

 stretched string, depending upon its length, 

 thickness, tension, and density. Vibrations 

 become audible when they reach the rate of 

 sixteen per second and vanish at the point 

 of 38,000 per second. Overtones are likened 

 to the wavelet3 which form part of a larger 

 ocean wave. The sound-waves, however, 

 divide with mathematical regularity, and the 

 laws concerning them were first formulated 

 by Helmholtz in 1863. The number and 

 strength of overtones, or harmonics, cause 

 us to recognize the difference between two 

 instruments, as flute and violin, when sound- 

 ing the same tone. The musical scale now 

 in use arose to fit the needs of keyed instru- 

 ments. The voice and stringed instruments 

 can give the natural scale with many more 

 intervals. Pitch has mathematical niceties, 

 and its standard is a variable quantity. 

 Philosophical pitch is determined by sub- 

 dividing a wire that vibrates once a second. 

 The variety of musical instruments has re- 

 sulted from employing different vibrating 

 substances, and from exciting vibration in 

 these by several methods. Six classes of 

 vibrations are noted : first, the vibrations of 

 strings ; second, of reeds ; third and fourth, 

 of elastic membranes ; fifth, of solid elastic 

 substances; and, sixth, "the vibrations of 

 air upon itself in a confined space." 



A consideration of orchestral instru- 

 ments naturally follows. These are grouped 

 as the string band, the " wood-wind," and 

 the brass band. In each of these divisions 

 are found four or more instruments that 

 correspond to the soprano, alto, tenor, and 

 bass in a vocal quartet. The modern or- 

 chestra dates from 1600; for, although the 

 ancients used many instruments, they per- 

 formed only unison-music, " while our idea 

 of orchestral music is essentially part-music." 



Rhythm, notation, marks of expression, 

 and musical embellishments are fully illus- 

 trated. Musical form is next analyzed and 

 traced to an origin in the old dances. The 

 suite was " at first a set of dance - move- 

 ments." In a study of figures and phrasing, 

 the author points out that the leit-motif so 

 characteristic of Wagner was first used by 

 Mozart in Don Giovanni. Among the musi- 



cal forms afflicted with changeable defini- 

 tions is the symphony, now understood as 

 a sonata for orchestra, but in the early part 

 of the last century known as a prelude, in- 

 terlude, or postlude. The development of 

 the sonata, its various movements and de- 

 pendent forms, follows, the more important 

 of these being the concerto and classical 

 overture. 



The Catholic mass is named as the earli- 

 est vocal form. Some vocal forms are the 

 offspring of instrumentation, such as the 

 aria and rondo. Vocal music of any char- 

 acter may be written either in the strophe 

 form, which repeats the music of one verse, 

 or as an art-song, in which the music inter- 

 prets the poem from beginning to end. The 

 canon, the fugue, and, finally, modern dance 

 forms are subjects of special study. 



In conclusion, the author recommends to 

 those wishing to become earnest musicians, 

 ensemble - playing and score-reading. The 

 German language should be acquired for the 

 philosophy and literature of music, but Ital- 

 ian is most important to the vocalist. 

 " Bach should be faithfully studied by every 

 musician," since in him "the intellectual 

 and emotional are so well balanced." 



War and the Weather. By Edward 

 Powers, C. E. Revised edition. Dela- 

 van, Wis. : Published by the author. 

 Pp. 202. Price, $1. 



A belief exists that heavy cannonading 

 and great fires bring on rain. In some 

 places it has been noticed often that a clear 

 morning on the 4th of July has been fol- 

 lowed by rain, and this has been attributed 

 to the explosive celebration of the day. 

 Mr. Powers has written his book to furnish 

 definite evidence in support of the belief 

 that rain can be produced by means of 

 artillery, and to advocate the making of ex- 

 periments by the Government in order to ob- 

 tain certain proof in regard to it. His evi- 

 dence consists of a record of those battles in 

 our Mexican and civil wars in which artil- 

 lery was largely used and which were fol- 

 lowed by rain, giving the chief circumstances 

 in each case. An appendix contains letters 

 from army officers, transcripts from diaries, 

 etc., supporting this record. In regard to 

 the fact that artillery-firing does not always 

 bring rain, the author says that the chief 



