Sentence:  If a musician were going to give a lecture upon the mathematical part of his art, he would find a very elegant substitute for the <WSD>monochord</WSD> in the Chinese kin. 
Meaning of the word marked with <WSD> tags:  A musical instrument for experimenting with the mathematical relations of musical sounds, consisting of a single string stretched between two bridges, one or both of which can be moved, and which stand upon a graduated rule for the purpose of changing and measuring the length of the part of the string between them.