The lay-sermon of Dr. Watson, deeply impressive by the power of the indisputable facts on which it was based, had a considerable effect in rousing public opinion, finding its way even into the dull ears of ‘such as commonly compose church vestries.’ Among the most important results was a step taken, after long and solemn deliberations, extending over several years, by the Dean and Chapter of St. Paul’s. They made an application to the Royal Society, asking for advice as to the best means of protecting the great cathedral, Sir Christopher Wren’s noblest creation, against the perils of lightning. The application was made on March 22, 1769, as recorded under that date in the ‘Gentleman’s Magazine.’ ‘A letter from the Dean and Chapter of St. Paul’s,’ it was stated, ‘was read at the Royal Society, requesting the direction of that learned body for the sudden effects of lightning. It was referred to a committee consisting of Dr. Franklyn (_sic_), Dr. Watson, Mr. Canton, Mr. Edward Delaval, and Mr. Wilson, who, after having examined the building, are to report their opinion.’ The committee thus nominated embraced all the most eminent men of the day who had studied the phenomena of electricity, and in the order in which they ranked. Next to the great discoverer of the lightning conductor himself, Dr. Watson could claim to stand; and next to him Mr. John Canton, a most painstaking and intelligent worker in the field, inventor of the pith-ball electrometer, and other instruments.
But a curious element of discord pervaded from the first this small conclave of learned men, chosen to decide the not unimportant question as to the best means of providing the cathedral of St. Paul with lightning conductors. That the noble building should be so protected, all were agreed; and it was clearly understood, besides, that if once St. Paul’s had lightning conductors, all the other cathedrals and principal churches of England would follow suit. What they differed upon was not this, but the best form of lightning conductors. Franklin’s steadfast assertion that points to the elevated rods were not only far preferable to any other form of conductors, but the only really protective ones, was adopted by Dr. Watson and Mr. Canton; but they were opposed by Mr. Wilson, who asserted, with some degree of vehemence, that points were dangerous, and that balls on the summit of the rods afforded infinitely better protection. Standing alone in this view among the eminent members of the committee of the Royal Society, his arguments naturally had no effect, and the recommendation to the Dean and Chapter of St. Paul’s was to protect the cathedral by pointed lightning conductors. This was done accordingly. ‘Franklin rods’ were attached to Wren’s splendid structure, worthy to be the introducer of them, on a large scale, in Europe.