152 THE APPLICATIONS OF PHYSICAL FORCES. [BOOK 11. 



were of metal ; they were tuned, some to unison and some to harmonize, 

 and were resonant by sympathy or concurring motion. The alto- 

 viola or quint, the viola da gamba or leg or bass-viol, and the contra 

 basso di viola, or double-bass viol, are the only three types used in the 

 present day, and are called the tenor, violoncello and double-bass. 



We have thought it interesting to the reader to illustrate some 

 types of instruments similar to the violin, taken from foreign 

 countries. The Persian arid Chinese violins do not appear to be 

 constructed with greater art than those of the African savage tribes, 

 or the violins of the Ouadjiji. They are very curious specimens of the 

 infancy of the art, and of types with which the Amatis, Stradivariuses 

 and Vuillaurnes have nothing in common but the name. 



IV. THE GUITAR THE HARP. 



The guitar and the harp are types of another class of stringed 

 instruments. In these the vibrations are not produced by the friction 

 of a bow, but by plucking with the fingers, or by striking with a piece 

 of wood or quill ; but, like instruments of the violin family, the notes 

 of the strings are strengthened by a sounding box, the vibrations 

 of the sides of which as well as the mass of contained air, heighten 

 the effect. 



In the guitar, the absence of the bridge, and the manner of 

 vibrating the strings, causes the notes to be of much less power and 

 sonorousness than those produced by bowed instruments. It also pro- 

 duces a very different tone, which gives to pieces played on the 

 guitar a light, sweet and also a melancholy character. Moreover, 

 this instrument is fitter for accompanying the voice than for solos. 



The number of tlie strings varies. Each of them is struck or 

 plucked, either on the open string, in which case it produces the 

 fundamental note, or when shortened by the pressure of the fingers 

 of the left hand, which press it on the frets arranged at convenient 

 distances on the finger-board. The performer always plays correctly 



1 Persons interested in the history of instruments will find curious specimens of 

 ancient instruments in the Museum of the Paris Conservatoire of Music, a collec- 

 tion which is constantly being enriched under the learned and zealous direction of 

 M. Chouquet, the director. 



