The two passages, taken in conjunction, leave no room for doubt that the object in placing the diamond hoop on the dagoba, was to turn aside the stroke of the thunderbolt.
But the question still remains, whether, at that very early period, the people of Ceylon had such a conception, however crude and erroneous, of the nature of electricity, and the relative powers of conducting and non-conducting bodies, as would induce them to place a mistaken reliance upon the contrivance described, as one calculated to ensure their personal safety; or whether, as religious devotees, they presented it as a costly offering to propitiate the mysterious power that controls the elements. The thing affixed was however so insignificant in value, compared with the stupendous edifice to be protected, that the latter supposition is scarcely tenable. The dagoba itself was an offering, on the construction of which the wealth of a kingdom had been lavished; besides which it enshrined the holiest of all conceivable objects—portions of the deified body of Gotama Buddha himself; and if these were not already secured, from the perils of lightning by their own sanctity, their safety could scarcely be enhanced by the addition of a diamond hoop.
The conjecture is, therefore, forced on us, that the Singhalese, in that remote era, had observed some physical facts, or learned their existence from others, which suggested the idea that it might be practicable, by some mechanical device, to ward off the danger of lightning. It is just possible that having ascertained that glass or precious stones acted as insulators of electricity, it may have occurred to them that one or both might be employed as preservative agents against lightning.
Modern science is enabled promptly to condemn this reasoning, and to pronounce that the expedient, so far from averting, would fearfully add to, the peril. But in the infancy of all inquiries the observation of effects generally precedes the comprehension of causes, and whilst it is obvious that nothing attained by the Singhalese in the third century anticipated the great discoveries relative to the electric nature of lightning, which were not announced till the seventeenth or eighteenth, we cannot but feel that the contrivance described in the Mahawanso was one likely to originate amongst an ill-informed people, who had witnessed certain phenomena the causes of which they were unable to trace, and from which they were incapable of deducing any accurate conclusions.
[Footnote 1: I have been told that within a comparatively recent period it was customary in this country, from some motive not altogether apparent, to surmount the lightning conductors of the Admiralty and some other Government buildings with, a glass summit.]