42 PIONEERS OF SCIENCE IN AMERICA. 



request of the college authorities, and an account of the 

 earthquake which Winthrop sent to the Royal Society was also 

 printed. 



At that time lightning rods had been invented about three 

 years, and a Boston minister published an essay in which he 

 suggested that the use of Franklin's "iron points" might 

 have caused the earthquake by drawing the electric fluid from 

 the clouds and concentrating it on that part of the earth. 

 This led Prof. Winthrop to add an appendix to his lecture in 

 which he defends the discoveries of his friend Franklin, and 

 shows the unreasonableness of attributing the earthquake to 

 the action of the rods. He concludes with the hope that he 

 has " fully vindicated the character of those innocent and 

 injured iron points." Some years after, in 1770, he seized 

 another opportunity to defend Franklin's invention, by pub- 

 lishing an essay against the notion that there was great im- 

 piety in using lightning rods, since they prevented the "tokens 

 of Divine displeasure " from " doing their full execution." 

 Under date of October 26, 1770, he writes to Franklin, who 

 was then in London, acknowledging the execution of several 

 commissions concerning books and instruments, and says in 

 regard to the rods : " I have on all occasions encouraged them 

 in this country, and have the satisfaction to find that it has 

 not been without effect. A little piece I inserted in our news- 

 papers last summer induced the people of Waltham (a town a 

 few miles from hence) to fix rods upon their steeple, which had 

 just before been much shattered and set on fire by lightning."* 



Prof. Winthrop had a clearer understanding of earthquake 

 movements than the generality of scientific men of his time, 

 and was one of the earliest, if not the first, to apply computa- 

 tion to these phenomena. The chimney of his house was thirty- 

 two feet high, and, observing that bricks were thrown from it 

 so that they fell thirty feet from its foot, he calculated the 

 speed of their motion and found it to be twenty-one feet a 

 second. He perceived also the resemblance between the vibra- 

 tions of the earth and those of the strings of a musical i^istru- 

 ment. 



The fullest published account of the scientific work of Prof. 

 Winthrop is contained in the chapter on Boston and Science, 



* Massachusetts Historical Society's Proceedings, vol. xv, p. 13. 



