Obrazy na stronie
[blocks in formation]

The Origin, Antiquiiy, and Progresŝ

of Electricity. Opinions of various Authors on Air.

***TTEMPTS to render Electricity * A * intelligible and plain have been to

often made, and with so little fuc

cess, that the Expectation of the Public is almost at an end; and 'till Tome more effectual method be pursued than what has been hitherto practis’d, so long that wonderful Appearance of Nature will remain inexplicable. Therefore, that one so unaccomplish'd and unlearned as I must own myself to be, shou'd presume to explain it, will doubtless be thought a vain and daring Effort, by MANY, who may be inclined to think that little more can be produced from my illiterate Labours, than from Æfop's teeming Mountain, which brought forth oniy a Mouse.

2. This was so natural and obvious, that I could not help foreseeing it my self in the strongest Light: The method therefore



proper for

my own

which appear’d to me the most eligible and unexceptionable, in order to guard against such an ill-favour'd Reflection, was, to collect the Opinions and Experiments of some of the moft celebrated and authentic Writers on this ambigudus Subject, particularly of Sir I. Newton, Mr. Hauksbee, and Dr. Franklin to lay their observations together; to compare them diligently and candidly; and to make use of whatever I found

my fixed purpose of investigating the Truth.

3. By such a careful, and, I think, rational method of proceeding, together with Experiments and Observations, I was encourag'd to hope that some farther Light might be reflected on this important Subject than ever was before.

But in order to elucidate, and render it more instructive and entertaining to the Reader, I must beg leave to prefix a brief account of the Origin, Antiquity, and Progress of it. 5.

This I in some measure anticipated by a former Publication; but as I have many Things to add to the Observations I then made, I now take the Liberty to place the whole here in one regular View.

6. The Term Electricity in great measure explains it self, being deriv'd from Electron, which is the Greek Name for Amber. 7. The Ancients, some thousand Years

ago, were not unacquainted with that Property in



Amber of attracting light Bodies afterrubbing it; for which Reason all other Things that were afterwards found to be endu'd with the like Qualities of Attraction, &c. were callid Electrics, and all others, Non-electrics.

8. The Reason why Electricity made luch flow Advances in the experimental Way, for fo many hundred Years, was, from its not being known that it escap'd throʻ other Bodies into the Earth; and more particularly from not knowing that all such Bodies, which are now callid Electrics per fe, were the only Bodies which could prevent such Escape, 9.

Of Bodies which are endu'd with this Quality, Glass is found to be one of the greatest of all, even much to exceed that of Amber itself.

10. The very first Man that we hear of, who was so happy as to make any

considerable Improvement in Electricity, is Mr. Hauksbee, Fellow of the Royal Society, near the latter end of the last Century; he discover'd many

of the Experiments, that are now exhibited, with a glass Tube; he also invented a method to turn glass Globes and Cylinders on their Axes, and nearly of the fame Construction with those that are now made use of, some in the common Way, others he exhausted of their Air, and then whirl'd theni on their Axes, and exhibited the appearance of Fire in various forms, and in some, in very great plenty.

B 2


11. The next considerable Improver of Electricity was Mr. Stephen Gray, of the Charter-house, who spent no small part of his 'Time in making such kind of Experiments, still improving on Mr. Hauksbee's glass Tube; but tho' we never heard that he made use of the revolving Globe or Cylinder, as Mr. Hauksbee did, yet he carry'd his Researches much farther than he, and from the great number of Experiments made by him, he may truly be said to have set on foot all the Discoveries that have been fince made on that curious Subject.

12. Dr. Defaguliers in the ist Vol. of his Course of experimental Philosophy, p. 450, tells us, that Mr. Gray had made a greater variety of electrical Experiments than all the Philosophers of this and the last Age*. It was he who discover'd that Glass, Amber, Refin; Wax, Silk, Hair, and all other electric Bodies, did not convey the electric Matter to other Bodies, nor suffer it to escape thro' them like Metals, Water, Animals, and some others, and consequently if he supported the lätter with the former, he might convey it to distant parts; this discovery was productive of

Notwithstanding this is true, and tho the World is greatly indebted to him for such indefatigable Pains and Industry; yet it must be own’d, that it is much more indebted to Mr. Hauck bec for pointing out the means.



another, viz. that such propagation of it to distant Bodies seem'd instantaneous, he himself having experienc'd it to be sensibly so, to the distance of 800 feet.

13. It was he who discover'd it to escape into the Earth, and having likewise discover'd, that what are since call'd electrics per se would prevent such escape, his method was to suspend à Person horizontally on two hair or filk Lines, then rubbing his glass Tube, and holding it near his Feet, his Face or Hands were instantly capable of attracting and repelling light Bodies.

14. He afterwards discover'd that more commodious method of electrising a Person, viz. By setting him on a Cake of Resin, Glass, or any other electrical Substance, and that it was equally the same as supporting him with hair or silk Lines.

15. A greater Improvement yet, was the introducing of the glass Globe, Cylinder, and Spheroid whirling on their Axes, instead of rubbing the glass Tube, the Power being by that means increas'd to a very high Degree.

16. Thus having brought it to such Perfection, a great Number of various Experiments

where made, particularly after it was discover'd lo plainly to be Fire, as to kindle up many particular Bodies into an actual Flame.

17. But the greatest Improvement of all, and what conducted to the finishing Stroke,

were every


« PoprzedniaDalej »