i 5 4 THE POPULAR SCIENCE MONTHLY. 



ing its cause being vouchsafed to the suffering sentient world. We 

 have been scourged by invisible thongs, attacked from impenetrable 

 ambuscades, and it is only to-day that the light of science is being let 

 in upon the murderous dominion of our foes. Men of Glasgow, these 

 facts excite in me the thought that the rule and governance of this 

 universe are different from what we in our youth supposed them to 

 be that the inscrutable Power, at once terrible and beneficent, in 

 whom we live and move and have our being and our end, is to be pro- 

 pitiated by means different from those usually resorted to. The first 

 requisite toward such propitiation is knoicledge ; the second is action, 

 shaped and illuminated by that knowledge. Of knowledge we already 

 see the dawn, which will open out by-and-by to perfect day, while the 

 action which is to follow has its unfailing source and stimulus in the 

 moral and emotional nature of man in his desire for personal well- 

 being, in his sense of duty, in his compassionate sympathy with the 

 sufferings of his fellow-men. " How often," says Dr. William Budd, in 

 his celebrated work on " Typhoid Fever " " how often have I seen in 

 past days, in the single narrow chamber of the day-laborer's cottage, 

 the father in the coffin, the mother in the sick-bed in muttering de- 

 lirium, and nothing to relieve the desolation of the children but the 

 devotion of some poor neighbor, who in too many cases paid the pen- 

 alty of her kindness in becoming herself the victim of the same dis- 

 order ! " From the vantage-ground already won I look forward with 

 confident hope to the triumph of medical art over scenes of misery 

 like that here described. The cause of the calamity being once clearly 

 revealed, not only to the physician, but to the public, whose intelligent 

 cooperation is absolutely essential to success, the final victory of hu- 

 manity is only a question of time. We have already a foretaste of 

 that victory in the triumphs of surgery as practised at your doors. 



THE PROTECTION OF BUILDINGS FROM LIGHTNING. 



By Peofessoe J. CLEEK MAXWELL, 



MOST of those who have given directions for the construction of 

 lightning-conductors have paid great attention to the upper 

 and lower extremities of the conductor. They recommend that the 

 upper extremity of the conductor should extend somewhat above the 

 highest part of the building to be protected, and that it should ter- 

 minate in a sharp point, and that the lower extremity should be car- 

 ried as far as possible into the conducting strata of the ground, so as 

 to " make " what telegraph engineers call " a good earth." 



The electrical effect of such an arrangement is to tap, as it were, 

 the gathering charge by facilitating a quiet discharge between the 



