818 Royal Society : — • 



familiar with, will be entirely superseded, and I think the sooner such 

 method becomes obsolete the better it will be for the interests of the 

 mariner, for, together with other advantages, the tedious operation 

 of a " day's work " will be divested of half the usual trouble. 



When giving a course to the " quarter-master," or " man at the 

 wheel," no mistake, so liable to be the case at present, can well 

 occur ; it will merely be necessary to direct him to steer, for instance, 

 " north five points east," or more briefly, " north five east," " south 

 six west," &c. &c. 



I recollect an instance of a vessel steering N.W. by N. ^N., 

 instead of W. by N. y N. during thick weather in the Bristol Channel, 

 thus running into danger from the similarity of sound between the 

 courses alluded to. 



The practical application of the decimal card would not materially 

 affect the charts previously published, which could have printed 

 compasses containing thirty-six points pasted over the others. Such 

 might be sold by any chart-seller. 



" Observations on the Human Voice." By Manuel Garcia, Esq. 



The pages which follow are intended to describe some observa- 

 tions made on the interior of the larynx during the act of singing. 

 The method which I have adopted is very simple. It consists in 

 placing a little mirror, fixed on a long handle suitably bent, in the 

 throat of the person experimented on against the soft palate and 

 uvula. The party ought to turn himself towards the sun, so that 

 the luminous rays falling on the little mirror, may be reflected on 

 the larynx. If the observer experiment on himself, he ought, by 

 means of a second mirror, to receive the rays of the sun, and direct 

 them on the mirror, which is placed against the uvula. We shall 

 now add our own deductions from the observations which the image 

 reflected by the mirror has aflTorded us. 



Opeyiing of the Glottis. 



At the moment when the person draws a deep breath, the epi- 

 glottis being raised, we are able to see the following series of move- 

 ments : — the arytenoid cartilages become separated by a very free 

 lateral movement ; the superior ligaments are placed against the ven- 

 tricles ; the inferior ligaments are also drawn back, though in a less 

 degree, into the same cavities ; and the glottis, large and wide open, 

 is exhibited so as to show in part the rings of the trachea. But 

 unfortunately, however dexterous we may be in disposing these 

 organs, and even when we are most successful, at least the third 

 part of the anterior of the glottis remains concealed by the epi- 

 glottis. 



Movement of the Glottis. 



As soon as we prepare to produce a sound, the arytenoid carti- 

 lages approach each other, and press together by their interior 

 surfaces, and by the anterior apophyses, without leaving any space, 

 or intercartilaginous glottis ; sometimes even they come in contact 

 so closely as to cross each other by the tubercles of Santorini. To 

 this movement of the anterior apophyses, that of the ligaments of 



