384 PROCEEDINGS Or THE AMERICAN ACADEMY 



" The committee appointed at the last meeting of the American 

 Academy of Arts and Sciences to examine Hedgcock's Patent Quad- 

 rant, which was submitted to the Academy, have attended to the duty 

 assigned to them and ask leave to report as follows. 



" A full meeting of the committee was held on the 14th of March, 

 at which Mr. Ayling was present. He then exhibited the new instru- 

 ment, and attempted to explain the peculiarities and pretensions of it. 

 The committee have handled the instrument, and have made them- 

 selves familiar with its construction ; which, as compared with that of 

 the ordinary quadrant, is defective in some points, and in others boasts 

 a superfluous complev'+-;^ which is the only thing original in the inven- 

 tion, or entitled to a patent. 



" The claim made for the instrument, namely, that by it differences 

 of latitude and longitude can be ascertained, rests upon no specified 

 discovery of a new law in nature, and can be shown, when analyzed, 

 to contradict the best determined laws. The reflecting quadrant is es- 

 sentially an optical instrument. In optics there are only two ways 

 known by which the direction of a ray of light can be altered, viz. 

 reflection and refraction ; and these changes of direction are the same 

 for polarized as for unpolarized light. To maintain, therefore, that, 

 when the images of an object have been brought into juxtaposition 

 with the object itself, and the glasses clamped, this juxtaposition will 

 not continue if the instrument is transferred to another place, and that 

 the motion which must be given to the glasses to restore the juxtapo- 

 sition will give the change of latitude and longitude, is to maintain 

 neither more nor less than this, — that the laws of the reflection and 

 refraction of light, which have been verified wherever there has been 

 an observer for the last two hundred years, are not constant any 

 longer, but have recently changed with the geographical position, 

 and in such a marvellous way as exactly to suit the special claim of 

 this Patent Quadrant. 



" In opposition to any testimony that may be adduced to prove that 

 this instrument has ever done what your committee say that it is inca- 

 pable of doing, the committee would simply urge the unanimous and 

 overwhelming testimony of mankind, not only of scientific men, but 

 also of all engineers, surveyors, travellers, and sailors who have suc- 

 cessfully determined their position by means of any quadrant or sex- 

 tant, not one of whom has ever discovered that every observation he 

 took with a reflecting a:lass was erroneous to the full extent of the dif- 



