On the Organs cf the Brain. 9 



keeping at the same time the object steadily covered by tlie hair ; 

 and when the card is stationary, the degree indicating the bear- 

 hig (which is seen by reflection, and considerably nuignifiwl 

 through the lens), may be read off to fifteen minutes by meatis 

 of tlie hair of the sight coming in contact witii the reflected 

 image of the divisions of tlie card. 



Should not the divisions on the card appear clistinct, the sight 

 next the eye is to be drawn out till they are perfectly well de- 

 fined. It is adviseable to tap the box gently with the finger, to 

 lessen any friction which might prevent the needle from settling 

 in the true direction. 



In addition to all the usual purposes of surveying to which this 

 instrument is apphcable, it may be employed with very superior 

 advantage as an azimuth compass, or to take hearings from a 

 boat at sea where the motion might wholly prevent the use of a 

 compass of any other form; and on such occasions it will be 

 f(»und far more accurate than the largest azimuth compass of 

 the common construction, and its use unattended with those 

 difficulties which frequently give rise to erroneous results. 



It would be unnecessary to point out all the various uses to 

 which this instrument may be applied ; but I may brieflv ob- 

 serve, that as an azimuth compass it stands unrivalled, and that 

 in land-surveying, and in the construction of maps of a country, 

 it will be found equal in accuracy to a large circumferentor, 

 though sufficiently portable to be carried in the waistcoat- 

 pocket. 



III. Of certain Causes which render more difficult the Discern- 

 ment of the Character of the Mind from the Examination 

 of the Organs of the Brain. By Thomas Forster, Esq. 



To Mr. Tilloch. 



Sir, — In pursuing the anatomy and physiology of the brain 

 and nervous system from the time of its first j)romu!gation in 

 England, I have been daily more and more convinced of the 

 truth of the doctrine maintained by Gall and Spurzheim. VVitii 

 the evidence now before me of their correctness, it would 

 be quite impossible that any arguments dravv-n from theory 

 should set aside a systematic arrangement of facts and a theoiv 

 deduced tlierefrom, in the support of which I coidd now advert 

 my mind to such, a numerous body of evidence. I have, however, 

 in the course of my observations, noticed tsevera! causes whv tlie 

 apparent indication of the organs were foimd in a degree falla- 

 cious ; and why wc <lid not always find the mind possessed of 

 energies couuneusuratc to the expectation wc had foruicd fr<'iiri 



au 



