Lightning Conductors to Powder Magazines. 497 



he will allow us, without offence, to urge upon him in conclu- 

 sion, the propriety of conducting this discussion temperately, 

 and of refraining from the indulgence of that spirit of injus- 

 tice which prominently characterises his remarks both upon 

 ourselves and upon Mr. McClelland, for no other reason that 

 we can see, than that we question the correctness of some of 

 his statements, and refuse our assent to some of his reason- 

 ings, on what we believe to be good and solid grounds. We 

 borrow the words of Sir John Herschell, in his elegant dis- 

 course on the study of Natural Philosophy, to embody what 

 we look for from Dr. O'Shaughnessy : — " We are not so un- 

 reasonable as to demand of him an instant and peremptory 

 dismission of all his former opinions and judgments ; all we 

 require, is that he will hold them without bigotry, retain till 

 he shall see reason to question them, be ready to resign 

 them when fairly proved untenable, and to doubt them when 

 the weight of probability is shewn to be against them. If 



HE REFUSE THIS, HE IS INCAPABLE OF SCIENCE." 



POINTS FOR DETERMINATION IN ACCIDENTS FROM LIGHTNING. 



With a view to obtain increased and trustworthy infor- 

 mation relative to the various circumstances connected with 

 accidents from lightning in this country, the following list 

 of points for determination has been prepared. It is very 

 far from being perfect, but it may still serve in some degree 

 to guide the inquiries of observers, and to direct their at- 

 tention to those leading points on which information is most 

 desirable, as well as to form a ground-work on which each 

 can rear his own superstructure. 



1. lYie Date of the Accident. 

 This should be specified with as much minuteness as cir- 

 cumstances will admit of, as much interesting information 

 relative to the course and effects of thunder storms may be 

 developed by the correct identification of the time. The 



