251 



The following communication from the Rev. Thomas 

 Knox was read : 



" River Glebe, Toomavara, 

 " April 9,1, 1842. 



" An application of the Daguerreotype process to astro- 

 nomical purposes occurred to me last autumn. It is well 

 known that an inscription on a building which it would re- 

 quire a telescope to read, from its smallness or distance, can 

 (if a view of that building be taken in the camera on one of 

 Daguerre's plates) be read by a microscope, though invisible 

 on the plate to the naked eye ; also, that the internal struc- 

 tui'e of some insects can be as well studied by examining the 

 image of the object on the plate by a microscope (that image 

 having been formed from the oxyhydrogen microscope). 



" From these known facts it is extremely probable that 

 were an image of a double star, or of one of the nebulae, taken 

 on a Daguerre plate in the focus of a telescope of moderate 

 power, but which of itself could not divide the star or resolve 

 the nebula ; that by then examining the plate by a strong 

 microscope, the state of that star, &c. might be ascertained, 

 as well as if it had in the first place been examined by a 

 telescope of very high power. 



" That the light of the fixed stars possesses chemical 

 rays, and would therefore affect Daguerre's plates, there can 

 be little doubt ; and I feel certain in my own mind that the 

 image thus formed would reveal to the microscope as much 

 as a telescope of equal power could in the first instance have 

 ascertained. 



" I am aware that theorising this way is very unprofit- 

 able, but I do not possess instrumental means for trying the 

 experiment myself, my equatorial not having any clock mo- 

 tion adapted to it. On the accuracy and steadiness of the 

 clocJc movement all would depend ; any small telescope, or 

 perhaps even a single lens, equatorially mounted, would do 



