336 



Prep on an inclwed pla?ie. 



[Oct. 



self once conceived, and so foreign to the ideas of com- 

 mon reasoners,that I venture to hope the following solu- 

 tions will he acceptable to your widely scattered readers. 

 That the props should not he * upright/ or perpendicu- 

 lar to the horizon, is a startling assertion, and I have 

 seldom met the man who did not at first consider the 

 proposition altogether absurd and erroneous. I am not 

 aware that these proofs are in print, and for the know- 

 ledge of them, I am indebted to a highly talented officer 

 of Artillery on the Bombay establishment, Capt. Jacob. 



The first and simplest demonstration is by the Rev. 

 G. Marker; — the author of the latter we do not know; 

 my own was founded on the former reasoning. With 

 every good wish for the success of the ' Journal/ be- 

 lieve me, 



It is required to determine the best position for the 

 supports of a gallery, on an inclined plane. 



Solution 1st. Let AB be the direction of the gal- 

 lery, AC perpendicular to the horizon, draw BC per- 

 pendicular to AB ; BC is the best position for the prop 

 or support. 



Yours sincerely, 



A Miner. 



