Chins and Projectiles. 113 



torn into about five lobes at the base. There are several 

 varieties of this moss with slight but persistent differences. It 

 is found on rocks and walls, sometimes on trees, and fruits in 

 February and November. 



The dense dull green or brownish tufts of Schistidium raari- 

 timum, or the Seaside Qrimmia, scarcely average an inch in 

 height, but have longer, narrower, and more rigid leaves, of a 

 glossy and almost horny consistence, and incurved when dry, 

 especially the perichastial leaves, which, though not hair- 

 pointed, have a strong excurrent nerve, of a reddish brown 

 colour. The capsule is soft, of a pale bright hue, obovate- 

 truncate in form, without an annulus, but with large teeth 

 much perforated, and a rostellate lid. It fruits in November 

 and December, and its rigid, strongly-nerved leaves sufficiently 

 distinguish it from the preceding. It is found on rocks near 

 the sea, but, it is said, f( seldom, if ever, on such as are 

 calcareous. " 



Thus we have described the whole family, as at present 

 known and arranged, genus and sub-genus, fifteen in number, 

 and we can promise, from experience, that whoever will take 

 the trouble microscopically to examine their peculiarities, and 

 verify our assertions, will open to themselves a source of 

 intense and abiding interest. 



GUNS AND PROJECTILES. 



It is probable that through the artillery experiments carried on 

 by the Government, and through the experience afforded by 

 the siege operations of the American war, the attention of the 

 public will once more be strongly drawn to the question of 

 arms and projectiles, and it may therefore be interesting to 

 many readers if we lay before them a few of the chief facts 

 and arguments pertaining to the question, and divested of those 

 technicalities which so often deter students from attempting to 

 understand mechanical problems. 



A little investigation will show that fire-arms furnish a 

 variety of conditions under which the laws and effects of motion 

 may be conveniently exhibited, and it is certain that no im- 

 portant improvement can take place in the military and naval 

 apparatus for attack and defence, without great benefit being 

 indirectly conferred upon the arts of peace. We shall not 

 attempt to trace the history of projectiles, but it may be as well 

 at the outset to correct a popular mistake, that the rude fire- 

 arms of our ancestors replaced the bow and arrow simply by 

 reason of their superiority in destructive power. This was 



