98 BOARD OF AGRICULTURE. 



find hydrogen predominating, and there are traces afforded of 

 thirteen of the other elements known to us. Now, we want 

 to carry our observations a little further, aud apply the spec- 

 troscope to the rays Avhicli come from Aldebaran, one of 

 the yellow stars. In this star there exists a considerable 

 amount of hydrogen, but we also find that the forms of matter 

 have undergone a striking modification, and the number of 

 metallic elements is largely increased. An advance is made 

 in the stupendous progress which is to end in the formation 

 of a world. If we carry the investigation another stage, and 

 appl}^ the spectroscope to the light of the red stars, still 

 further progress is observable. We find an entire absence of 

 hydrogen, nitrogen, and all those attenuated forms of matter 

 in red stars and the metalloids appear, and also their com- 

 pounds. It would appear that by a process of celestial 

 chemistry, the complex is evolved from the simple forms of 

 matter. First, the uebuloe, which is matter in a state of 

 extreme attenuation ; then the white stars, which have pro- 

 gressed a single stage, and are the hottest ; then the yellow 

 stars, which are cooler aud more progressed ; and, finally, the 

 red stars, which are the coolest, and approximate nearer to 

 the condition of our planet, than any of the others. I present 

 these views very briefly, that you may obtain some idea of 

 how, by successive steps, from matter in gaseous condition, 

 under the influence of heat, solid bodies like rocks result 

 from loss of temperature and condensation. 



Bowlder rocks are but the representatives of the mountain- 

 rock masses ; and let me here define what is meant by " bowlder 

 rocks." The term used to be applied to that class of stones 

 which are found in running streams and in the beds of rivers, 

 rounded and polished by attrition ; but it is more proper to 

 apply the term to all rocks which are resting upon our farms 

 "out of position," no matter what may be the form or size. 

 Almost every farm in New England has more or less of these 

 bowlders, these detached masses of rock, torn from their beds, 

 and resting out of their places. Over large tracts of country, 

 where there are no bed rocks, no ledges or quarries, bowlder 

 rocks are thickly strewn, and they are of various kinds, colors 

 and forms, hardly any two masses being alike. 



Now, the question arises, From whence came these rocks, 



