78 Localities of Minerals. 



a limited acquaintance with nautical affairs, the machine is at once 

 ingenious, cheap and simple, and likely to prove effectual. 



It is said that a machine for ventilating confined places was invent- 

 ed in England by Dr. Hales ; its principles were stated to be similar, 

 but its structure more complex, and not well adapted to marine use ; 

 and it does not appear to have been so applied. We understand that 

 Mr. Whiting intends that his machine should be used in prisons, hos- 

 pitals and other situations, which it may not be convenient always to 

 ventilate in the usual modes, and in every case of this kind, it is ob- 

 viously susceptibWof useful application. Even where chlorine and 

 its preparations have been used to destroy noxious effluvia, it may be, 

 and generally would be necessary that the premises should be after- 

 wards ventilated, and their situation might render it very desirable to 

 use such a machine as the marine ventilator. 



It might be used, with much advantage, in removing the carbonic 

 acid gas (the damp of the common people,) from wells, as bad air 

 would be replaced by good, and if there were no source from which 

 die noxious gas might flow in again, the cure might be permanent. 



Art. XVI. — JYotice of some Localities of Minerals, in the coun- 

 ties of Baltimore and Harford, Md. ; by Philip T. TYSoijr. 

 With an Appendix, by C. U. Shepard. 



1. Fine grained dolomite, (mag. carb. of lime,) embracing lamel- 

 lar talc and crystallized and granular pyrites ; fourteen miles from 

 Baltimore, and one fourth of a mile west of York turnpike. Also 

 the compact variety of mag. carb. of lime ; one mile west of the 

 13 mile stone on York turnpike road. 



2. Chalcedony, of a sky blue color, translucid and beautiful ; half 

 a mile east of where the Western Run crosses the York turnpike. 

 Agate and carnelian, in thin coatings upon chalcedony ; near the 

 Falls turnpike, four miles from Baltimore. Agate is found also thir- 

 teen and a half miles from the city on the York turnpike. 



3. Tourmaline, {cylindroide oi Haiiy,) of a brownish green color; 

 occurs in quartz on the York turnpike, fourteen and a half miles from 

 the city. Also {tredccimale of Haiiy) in granular limestone, three 

 fourths of a mile E. S. E. of where the York turnpike crosses the 

 Western Run. 



