like a Lattice, drill’d through with abundance of small holes; which probably may be the Reason, why the Ingenious Dr. Power seems to suppose them such.  In the Sunshine they look like a Surface cover’d with golden Nails; in another posture, like a Surface cover’d with Pyramids; in another with Cones; and in other postures of quite other shapes; but that which exhibits the best, is the Light collected on the Object, by those means I have already describ’d.

And this was undertaken in prosecution of the Design which the ROYAL SOCIETY has propos’d to it self.  For the Members of the Assembly having before their eys so many fatal Instances of the errors and falshoods, in which the greatest part of mankind has so long wandred, because they rely’d upon the strength of humane Reason alone, have begun anew to correct all Hypotheses by sense, as Seamen do their dead Reckonings by Coelestial Observations; and to this purpose it has been their principal indeavour to enlarge & strengthen the Senses by Medicine, and by such outward Instruments as are proper for their particular works.  By this means they find some reason to suspect, that those effects of Bodies, which have been commonly attributed to Qualities, and those confess’d to be occult, are perform’d by the small Machines of Nature, which are not to be discern’d without these helps, seeming the meer products of Motion, Figure, and Magnitude; and that the Natural Textures, which some call the Plastick faculty, may be made in Looms, which a greater perfection of Opticks may make discernable by these Glasses; so as now they are no more puzzled about them, then the vulgar are to conceive, how Tapestry or flowred Stuffs are woven.  And the ends of all these Inquiries they intend to be the Pleasure of Contemplative minds, but above all, the ease and dispatch of the labours of mens hands.  They do indeed neglect no opportunity to bring all the rare things of Remote Countries within the compass of their knowledge and practice.  But they still acknowledg their most useful Informations to arise from common things, and from diversifying their most ordinary operations upon them.  They do not wholly reject Experiments of meer light and theory; but they principally aim at such, whose Applications will improve and facilitate the present way of Manual Arts.  And though some men, who are perhaps taken up about less honourable Employments, are pleas’d to censure their proceedings, yet they can shew more fruits of their first three years, wherein they have assembled, then any other Society in Europe can for a much larger space of time.  ’Tis true, such undertakings as theirs do commonly meet with small incouragement, because men are generally rather taken with the plausible