Endeavour to obtain strings of uniform thickness throughout, a requisite which can only be insured by careful gauging. In selecting the E string, choose those that are most transparent; the seconds and thirds, as they are made with several threads, are seldom very clear. The firsts never have more than a few threads in them, and hence, absence of transparency in their case denotes inferior material. Before putting on the first string, in particular, in order to test its purity it will be well to follow Le Roy's advice, which is to hold between the fingers of each hand a portion of the string sufficient to stretch from the bridge to the nut, and to set it in vibration. If two lines only be apparent, the string is free from falseness; but if a third line be produced, the contrary conclusion must be assumed. In the case of seconds and thirds we cannot always rely on this test, as the number of threads used in their manufacture frequently prevents the line from being perfectly clear. The last precaution of moment is to secure perfect fifths, which can only be done by taking care that the four strings are in true proportion and uniform with each other. To string a violin correctly is a very difficult undertaking, and requires considerable patience. The first consideration should be the constitution of the Violin: the strings that please one instrument torture another. Neither Cremonese Violins nor old instruments in general require to be heavily strung: the mellowness of the wood and their delicate construction require the stringing to be such as will assist in bringing out that richness of tone which belongs to first-rate instruments. If the bridge and sound-board be heavily weighted with thick strings, vibration will surely be checked. In the case of modern instruments, heavy in wood, and needing constant use to wear down their freshness, strings of a larger size may be used with advantage, and particularly when such instruments are in use for orchestral purposes. [Illustration: _Plate III_. VIOLONCELLO BY ANTONIO STRADIVARI. PRESENTED TO SIGNOR PIATTI BY GENERAL OLIVER. (Herr Robert Mendelssohn.)]