182 LECTURES TO SCIENCE TEACHEES, 



APPENDIX III. 



SINCE the delivery of the above lectures, another harmonium 

 has been sent to the Loan Collection by Herr Appunn, of 

 Hanover, on the system of true temperament. The detailed 

 account of its mechanical appliances has not as yet arrived ; 

 but it may be briefly described as having thirty-six keys 

 playing thirty-five perfect fifths; the major thirds being 

 tuned by eight fifths downwards, that is, a sckisma too flat. 

 These are arranged in one row of keys, with two rows of 

 buttons or studs. The keyboard is double, with an extra 

 row of twenty-four tones arranged on the ratio 16 : 19 with 

 respect to the two bottom rows, so as to compare the effect 

 of the minor chord, using 16:19 with the usual 5 : 6. 



