MrcrocrRaPHin, og 
appear the brighter,throw towards the eye a multitude of {mall fefleGi= 
ons of light, whereas the darker {carceafiord any.. The reafon‘of which 
reflection, the AGcrofcope plainly dilcoyers, as appears by the Figure. In 
which you may perceive, that the brighter parts of the furface -confift of - 
an abundance of large and ftrong reflections,denoted by’ a, a} 2} .,4, &el 
for the furfaces of thofe threads that run the long way, are bythe Mechas 
nical procefs of watering, creas'd or angled in another kind.of pofture | 
then they were by the weaving: for by the weaving they are ovely bent 
ronwnd the warping threads; but by the watering, hap are bent with att 
angle, or elbow, that is inftead of lying, or being bent rexzd the threads, 
as in the third Figure, 4; 4, 4, a, a, are about b,b,b (b,b, reprefenting the 
ends,as ‘twere, of the crofsthreads,they are bent about) they,are creas d 
on the top of thofe threads, with an’ 4agle, as in the: fourth Figure, and: 
that with all imaginable variety; fo that,whereas before they reflected 
the light onely from one point of the round furface, as about e,¢;¢, they | 
now when water’d, reflect the beams ftom more then half the whole furs 
face,as.dé, de, de, and in other poftures they returnno refletions at all | 
from thofe furfaces. Hence in one pale they compofe the brighter 
. parts of the waves,in another the darker. And thefe reflections are alfo 
varied, according as the particular parts are varioufly bent. The reafon 
| of which creafing we fhall next examine; and here we muft fetch our in- 
formation from the Mechanifm or manntr of pracéeding in this operation 5 
~ which, as I have been inform’d, is no other then this. 
They double all the Stuffthat is to:be water'd, that is,they creafeitjuft © 
through thie middle of it, the whole length of the piece; leaving the a 
fide of the Stuff inward, and placing thetwo edges, or filvages juft upon 
one another,and,as near as they can,place the waledo in the doubling of it, 
that the wale of the one fide may lie very near parallel, or even with the , 
waleof the other ; for the nearer that pefture they lie, the greater.will 
the watering appear 5 and the more obliquely,or acrofsto each other.they | 
lie,the fmallerarethe waves. Their way for folding it for a,great wale 
isthus: they take a Pin,and begin at one fide of the piece in any wale. 
fo moving it towards the other fide, thereby direét their hands to the op- 
pofite ends of the wale, and then, as near as they can, place the two op- 
pofite ends of the fame wale together, and {o double, or fold the whole 
“piece, repeating this enquiry with a Pin at every yard or two's, diftance 
through the whole length ; then they fprinkle it with water,and fold it the 
longways, placing between every fold apiece of Paftboard, by. which’ 
means all the wrong fide of the water'd Stuff becomes flat, and with little 
wales, and the wales on the other fide become the more’ protuberyant 5 
whence the creafings or angular bendingsof the wales. become. the more 
perfpicuous. Having folded it in this manner,they-place it. with an inters 
jacent Paftboard into am hotPrefs, where it is kept very violently, preft, 
till itbe dry and ftiff; by which means; the wales of either contiguous | 
fides leave their own impreflions upon each other, as. is, very manl- | 
feft by the fecond Figure, where tis obvious enough, that thewale of the | 
piece 4 B C Duns parallel —— lines ef, ef, ef; er ' 
2 thanifelt 
