] 62 Mr Henwood an the Phenomena ()f 



nearly parallel in direction, but having opposite dips towards 

 each other in descent, giving a large V on the end view ; frac- 

 tured nearly at right angles to their direction, and the portion 

 on one side of the fissure to be elevated vertically. It is plain 

 that the lower and narrower part of the V on the elevated side, 

 will be brought opposite the upper and wider portion of the letter 

 on the unmoved side. Let us then imagine all the portion ele- 

 vated above the former surface to be removed, and take a view 

 of the horizontal plan presented, we have the fissure represent- 

 ing a cross-course, and one of the fractured veins will be heav- 

 ed to the right, and the other to the left. If both veins had 

 dipped the same way, it is obvious they would have been heav- 

 ed the same way ; whilst, if the line of elevation, instead of be- 

 ing vertical, had been coincident with the dip of one of the 

 veins, and the two were not parallel in dip, one vein would be 

 merely intersected, whilst the other would be heaved. 



This beautiful and ingenious illustration exhibits very satis- 

 factorily that, if the dip be irregular, so, in proportion, will be 

 the distance of the heave. 



It is also evident that these are not only possible, but INEVI- 

 TABLE results ; and that, if two veins having opposite dips be 

 displaced by the same vertical motion, it is " physically impos- 

 sible" that they can be heaved otherwise than towards different 

 hands. The object of my already-named communication to 

 the Geological Society was to shew that this county afforded 

 instances inexplicable on any one simple motion assumed ; but, 

 for reasons with which I was never made acquainted, this pa- 

 per was kept by the officers about a year, before it was read to 

 the Society. Professor Phillips says, "Several remarkable 

 cases which occur in the mines of Cornwall have been simply 

 explained by Mr Lonsdale." I presume those I gave are in- 

 tended ; but it would have been desirable to have known what 

 number of them was left unexplained. Moreover, we are, I 

 think, restricted rather within the limits of bare possibility, 

 and tied to probability too ; are the motions required for sim- 

 ple explanation likely ? Is there any evidence of their occur- 

 rence but their convenience ? For, if allowed to assume motions 

 of any masses, by any forces, to any distances, and in any times 

 required, our limits will be indeed extensive. 



We will now see how nearly this most beautiful theory coin- 



