Prhtlfig from Glafs Plates hy the RslUng Frvfs. 6 1 



were viewed by tranfmitted light, fuggeftcd the pofTibility of formally etching with deli- 

 cacy and perfettion upon glafs. This thought no fooner occurred than it challenged fomc 

 attention in confcquence of perceiving that glafs, from its extreme hardnefs and lubricity, 

 would preferve the execution beftowed upon it vaftly longer than copper-plate, were it 

 pofTible to introduce its fervices at the rolling prefs. But whilfl harbouring thefe furmifes, 

 the extreme fragility of glafs-plate, contrafted with the violent preffure it muft endure 

 between the rollers, had well nigh made me rclinquifh ihem altogether. It often happens, 

 however, that things, which at the firlt glance feem very unattainable, yield to a little re- 

 flexion, when they are fairly fet before the mind in the light of valuable defiderata. 



In the prefent cafe it foon became very evident, that the thinned and fraileft piece of 

 glafs-plate, whether ftraight or uneven, could, In regard to the flrongeft preffure, either 

 general or topical, be, rendered as robuft and as rigid as iron or Heel. The expedient 

 which occurred to me for that purpofe, confided in nothing but joining the glafs-plate 

 to flat pieces of tiiefe metals, of confiderable thickaefs, by an intervetlinglamina of proper 

 cement, taking care that it affords a very complete cqntaCl. 



Agreeable to this it is well known, that fo far back as the year 1791, by fortifying glafs- 

 plates of a moderate fize in this way, and aiding them further by a fimple apparatus on 

 the prefs board, I fucceeded completely in making them pafs fafely' between the rollers, 

 and in obtaining many impreffions, fuch as the fluor acid by the procefs of etching could 

 afford. Upon finding, however, that the beft of thefe etchings were very paltry, and ftiJl 

 regarding the f^fe paffage of the glafs between the rollers as an interefting experiment, I 

 was infenfibly led to confider, whether by the lapidary's wheel, or by any other poffible 

 means whatever, we could fo operate upon glafs-plate as to render it a produftive fubject 

 it the rolling prefs. This ftep appeared of fome confequence, as being all that was now 

 wanted for eflablifliing an improvement not deftitute of importance. Not long after, 

 certain views and methods occurred to me, which recently have been prbfecuted experi- 

 mentally, and which raife confiderable expeflatiens of our obtaining the maftery over aa 

 art, whereby the tame fcratchings of the fluor acid would be left far behind,, and tlie 

 execution and fpirit of the graver itfelf transferred from copper-plate to glafs-plate, in 

 infcriptions of all kinds, and in^efigns or embcllifliments of any fort, efpeciaily where 

 hatching conftitutes the manner; and all this with the further advantage, that any 

 number of fuch glafs-plates may be obtained quite alike, as being derived from the fame 

 original pattern. 



i The means of effecting a matter of fuch apparent difficulty, like moft other advances 

 ■in the Arts, or even in the Sciences, as foon as ever propounded, will, doubtlefs, be 

 thought extremely fimple and obvious. But whatever fmall portion of merit may be al- 

 lowed in the prefent inftance, ftiould the means prove fully adequate to the end, it will 

 partly confift, as will be feen immediately, in my having given an entire new direftion to 

 another ingenious art which has been long, cultivated, and by none with fo much genius 

 and ability as by the jufliy celebrated Mr. laffie of London. 



In November laft, certain circumftances recalling my attention to, the prefent objed, I 

 was led to explain, by letter to Mr. Taffie., the method of printing at the rolling prefs with 

 glafs-plates, and to fpecify to him, at fome length, the .fteps by which I wiflied him im..» 



5 mediately 



