104 Junction of Trap and Sandstone. 



perlments, with an instrument which promised to be of so little use ; . 

 and if it was not to confirm Mr. Gay Lussac's remarks, and prove 

 the superiority of the barometer, I should not have considered the ex- 

 periments with the cyanometer worth communicating to the world. 



I am aware, that among scientific men, there is an unbelief of 

 the fact, that intensity of darkness increases as ive recede from the 

 earth, but I do not consider it my duty here, to enter on a proof of 

 the assertion, or attempt to explain the cause which produced it. 1 

 should infringe on your pages, with a work which I do not feel com- 

 petent to perform, and will leave that for more able pens than mine. 

 The world may expect to have soon, a rich intellectual treat on that 

 subject, from a gentleman in Baltimore, whose scientific acquire- 

 ments, added to his profound reasoning and lucid mind, I am satis- 

 fied (from personal acquaintance,) render him in all respects, com- 

 petent to perform the task. 



My object in this communication, is to explain the principles of 

 my improvement in the barometer, to point out its advantages over 

 all others, and induce the world, through your widely circulating 

 Journal, to use the globe in all cases where the instrument is requi- 

 red to he portable. — If science can be improved, and mankind re- 

 ceive a benefit from this effort, it will afford me much pleasure to 

 have contributed a mite to so noble a cause. 



Jersey City, 28th July, 1834. 



Art. IX. — Junction of Trap and Sandstone; Wallingford, Conn. 

 By A. B. Chapin, Esq. 



The geology of the township of Wallingford, affords little of in- 

 terest to a superficial observer, the whole surface presenting low wa- 

 ving ridges of sandstone, with occasional ridges and peaks of trap, 

 (greenstone), and the whole mostly covered with a soil resulting 

 from the disintegration of the sandstone, which is in many places a 

 puddingstone. 



The dip of the strata, with some partial exceptions, is eastward at 

 an angle of from ten to fifteen degrees ; and the general course of 

 the trap ridges from north to south. The following section, cutting 

 Wallingford through the center from east to west, will give the rela- 

 tive situation of the different rocks. 



