34 Mr. D. D. Heath on the Problem of Sea-levels. 



In this case, as Dr. King remarks, " there was no dislocation 

 or fracture of the vertebral column, or injury of the ligaments 

 or of the spinal cord. - " 



Case II * On the 11th of May, 1858, Patrick Lydon was hanged 

 in Galway for the murder of his wife. Lydon was a small man, 

 only 5 feet 5 inches in height; the diameter of the rope was 10 

 lines; his weight was 9 \ stone, and the drop 11 feet. Hence 

 we find 



work done = 133 x 11 = 1463 foot-pounds. 



In this case, "that portion of the anterior common ligament 

 of the spine which passes from the body of the second to that of 

 the third cervical vertebra was ruptured, so that the left halves 

 of the bodies of the above-mentioned vertebrae were separated 

 from each other by an interval of one-eighth of an inch, but 

 there was no displacement." 



These criminals were executed with the same rope, and death 

 in the second case was not preceded by violent muscular convul- 

 sions, as in the first case — a fact which is readily accounted for 

 by the excess of shock in the proportion of 1463 to 1102. 



V. On the Problem of Sea-levels. 

 By D. D. Heath, M.A., F.G.S.f 



IN a paper published in March last, I investigated the ques- 

 tion recently mooted among geologists as to the effect of an 

 ice-cap, or other accumulation of superficial matter, in locally 

 altering the mean sea-level. 



I was more familiar with the formulas required than with La- 

 place's mode of using them; and I partly misunderstood and 

 misapplied his method. My labour was not, however, wasted ; 

 for I had rightly deduced the external form, or contour-line, 

 which a sea covering a denser solid spherical nucleus would 

 assume under the influence of an external capping supposed to 

 be anyhow kept at a definite distance apart from it. My error 

 lay in arguing that, when the agency keeping them apart is a 

 solid connexion between the cap and the nucleus, this nucleus 

 will, to the first order of small quantities, lie centrically within 

 the envelope. 



This error I corrected in April, and explained that the centre 

 of the solid sphere will be, as it were, depressed by the superin- 

 cumbent weight of the cap, and lie away from the centre of figure 

 in the opposite direction by a distance of the same order of mag- 



* Dublin Quarterly Journal of Medical Science, August 1863. 

 t Communicated by the Author. 



