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,;_ ,. 263.— Clafs and order, Hexaiulna Moiwgyn'ui- Nat. 

 Ord. J unci, Juff. Junccn, Br. , ,• > 



Eff. Ch. Calyx inferior, tubular, falver-lhaped ; limb 

 coloured, in fix deep fegments. Stamens inferted into the 

 mouth of the tube. Anthers linear, convergnig, attaclied 

 by the bafe. Germen of one cell, with rudiments of three 

 erea feeds. Stvlc thread-fhaped. Stigma iimple. Cap- 

 fule membranous, fingle-feeded, enclofed in the hardened 



tube of the calyx. ^ .^ 



i.C.cyanea. Blue Cakaafia. Br. n. i. Bot. of Terra 

 Auttr. 77. t. 9.— Found by Mr. Brown, on the louthcrn 

 coall of New Holland.— A little ihrub, flowering in De- 

 cember, very much branched, clothed with acerofe nieathing 

 leaves. Floivers folitary, at the ends of the fhort branches. 

 Tube of the calyx covered by the fheaths of the leaves ; 

 the limb prominent, like a bright blue ftar, of fiji equal 

 rays, the three outermoft downy underneath. This pretty 

 genus is not very nearly allied to any other, though fomc- 

 thing hke Jphyllanthes, but widely different in ftruaure, 

 ,-ind rather approaching Dasyfogon, hereafter to be 

 defcribed. 



CALEDONIA, a county of Vermont, 1. 2, ;■. 23 ; 



add In 1810, it contained 18,750 inhabitants. 



CALEIDOSCOPE, or Kaleidoscope, from ;cxXo.-, 

 beautiful, aJo;, a form, and rr^Tst , to fee, an milrument re- 

 cently invented bv Dr. Brewfter, and for which he has 

 obtained a patent, for the purpofe of creating and exhibiting 

 an infinite variety of beautiful forms. 



The inftrument in its fimplefc form confifts of two 

 reflefting planes, inchned to each other, made either of 

 two pbtes of glafs, blackened or filvered, or two metallic 

 lurfaces, or the two inner furfaces of a folid prifm of glafs, 

 or rock-cryftal, from which the liglit fuffers total reflection. 

 The plates may be of any length ; but that which is mofl: con- 

 venient will be found to be from five to ten or twelve inches, 

 or they may be made only two, three, or four inches long, 

 provided diftinft vifion is obtained at one end, by placing at 

 the other end an eyc-glafs, whofe focal length is equal to the 

 length of the refleaing-plane ; their breadth iliould be 

 about eight or nine-tenths of an inch when the lenglli is 

 fix inches ; but it (hould increafe with the length, in order 

 to have the aperture of the fame angular magnitude. Two 

 edges of thefe refleaors, being made perfeaiy ftraight, are 

 placed too-ether by a particular contrivance, in fuch a 

 manner, that their inclination, or the angle which they form, 

 is exaaly an even aliquot part of a circle, or a fourth, fixth, 

 eighth, tenth, twelfth, fourteenth, &c. part of 360"^. When 

 the plates are thus fixed in a tube, and the eye placed at 

 one end, as near as can be, in the line of the interkaion of 

 the two planes, it will perceive a circular field of view, com- 

 pofed of as many luminary feaors as the number of times 

 the angle formed by the refleaors is contained in 360°. 

 Thefe feaors, excepting the one feen by direa vifion, and 

 conftituting the angular aperture of the plates, are a feries 

 of images of this aperture, formed by fucceffive refleaions 

 between the inchned refleaors. The images formed by 

 one refleaor from each of the plates lie on each fide of the 

 direa aperture, and are inverted images of that aperture ; 

 the next two images formed by two refleaions are images 

 Tiot inverted ; and fo on throughout the whole feries, every 

 two direa images being feparated by an inverted one. 



Trom thefe obfervations, it will be feen that the caleido- 

 fcope is not an inftrument which produces beautiful forms 

 by the mult'iplkalmi of Jingle forms ; for it is demonllrable, 

 ■ that a fymmetrical and beautiful pattern cannot be produced 

 by the repetition of any fingle form : and if it were poffible 

 io conftrua a multiplying-glafs with mathematical perfec- 



6 



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tion, and free from all the prifmatic colours, it would be 

 impoffible to produce with it an arrangement of fimpk- 

 forms, marked with fymmetry and beauty. Tiie principle 

 of the caleidofcope, therefore, is to produce fymmetry and 

 beauty by the creation and fubfequent multiplication of 

 compound forms, each of which is compofed of a direa 

 and an inverted image of a fimple form. 



The tube which holds the refleaing plates moves in 

 another tube ; and upon the outer end of the laft tube 1^ 

 placed a cell, or cap, for receiving a feries of objea-plate.', 

 containing fragments of differently-coloured glafs and 

 other fuljftances placed at random. When one of thefe 

 objea-plates is placed in the cell, the inner tube is puflied 

 in as far as it will go ; and the inftrument being held in 

 one hand, the cell containing the objea-plates may be 

 removed round with the other, and the eye of the obferver 

 being placed at the other will obferve the irregular maffes 

 of colour arranged in an infinite variety of forms, mathe- 

 matically fymmetrical, and highly pleafing to the eye. 



If the objea be put in motion, the combination of images 

 will likewife be put in motion, and new forms, perfeaiy 

 different, but equally fymmetrical, will fucceffively prefent 

 themfelves ; fometimcs varying in the centre, fometimes 

 emerging from it, and fometimes playing around it in double 

 and oppofite ofcilLitions. When the objea is tinged with 

 different colours, the moll beautiful tints are developed in 

 fuecefiion, and the whole figure delights the eye by the 

 perception of its form, and the brilliancy of its colouring. 



The effeas, of which we have given a general defcription, 

 obvioufly arife from inverfion and fubfequent multiplication 

 of every objea placed before the angular aperture, or the 

 luminous feaor feen by direa vifion, and from the perfea 

 jiinaion of all the refleaed images. When the objea is 

 moved, the inverted images all feem to move in an oppofite 

 direaion, while the images not inverted move in the fame 

 direaion with the objea : and from thefe oppofite motions, 

 as well as from the entrance of new objeas, by the revolu- 

 tion or the direa motion of the objea-plate, arifes that 

 cndlefs variety of forms v^'hich affords fo much gratification 

 to the eye. 



In the preceding form of this inftrument, the objea 

 muft necefiarily be placed clofe to the end of the refleaors ; 

 for if it is removed from this pofition, the fymmetry is 

 deftroyed, and the deviation from a fymmetrical form in- 

 creafes as the diftance of the objea from the refleaor 

 increafes. The ufe of the inftrument in this form is, there- 

 fore, limited to objeas which can be held clofe to the re- 

 fleaor. ... 



This limitation, however, has been fuperfeded ; and the ufe 

 and application of the inftrument indefinitely extended by 

 an optical contrivance. A lens of a fliort focal length is 

 placed on the objea end of the outer tube, and the inner 

 tube is drawn out till the image of objeas, whatever be 

 their diftance, falls exaaiy on the outer end of the refleaors. 

 When this is the cafe, thefe objeas will be arranged into 

 the moft beautiful and fymmetrical forms, in the fame 

 manner as if they had been reduced in fize, and aaually 

 placed at the end of the refleaors. In this way, every 

 objea in nature may be introduced into the piaure formed 

 by the inftrument, and the obferver will derive a new and 

 endlefs fource of enjoyment by the creation of piaures of 

 natural objeas, whether animate or inanimate. 



As the caleidofcope is of great ufe in the ornamental arts, 

 particularly to carpet and lace manufaaurers, calico-printing, 

 paper-ftaining, jewellery, &c. &c., its adaptation to their 

 purpofe is effeaed by occafionally furniftiing the inftru- 

 ment with a ftand, in order that the pattern may be fixed 



whilft 



