532 ISLE OF MAN. GEOLOGY. 



broken in the act of quarrying, and applied to the pur- 

 poses of building stone ; the flatness of their surfaces, 

 and the angles of their joints, adapting them particularly 

 to dry stone work, as well as to the ordinary objects 

 of masonry. 



A more rare variety of schist, applicable, like the former, 

 to economical purposes, occurs at Spanish head and in 

 its vicinity, where quarries have been opened. It is of 

 a fibrous texture, and is capable of being raised in long 

 beams, extending from twelve, even to eighteen feet in 

 length. These are used for lintels and similar objects, 

 and are admirably adapted for many other architectural 

 purposes, too obvious to require mention. As yet they 

 have not become the subjects of export; the duties on 

 the internal commerce in stone, producing here, as in so 

 many other instances, the effect of a prohibition. They 

 possess a property not often observed in rocks, namely, 

 that of flexibility ; returning to their places, like other 

 elastic substances, when the bending force has been re- 

 moved. In some trials, made for this purpose, it was 

 found that a beam of fifteen feet in length was forced 

 five inches out of the straight line before it broke ; its 

 thickness being two inches. 



Among the other economical varieties of schist, a kind 

 of hone slate occurs at a place called Montpellier. It 

 is of a whitish colour and soft texture, better adapted for 

 the polishing of metallic plates than the uses of the cutler. 

 It has not been exported. 



The last variety of this rock which it seems necessary 

 to notice at present, is drawing slate. This is to be seen 

 near Peel, at the point where the junction of the red 

 sandstone with the schist is visible. The specimens which 

 I procured were not of a very good quality, but as the bed 

 is of considerable thickness and varies much in its texture 

 in different parts, it is possible that, with a patient re- 

 search, better might be found. This substance forms also 



