45, CORNHILL, B.C., AND 122, REGENT STREET, W., LONDON. 221 



FIG. 687. FIG. 686. FIG. 685. 



678 French Pattern Spectacles, (fig. 678) with Single or & a s ' a. & B. ' d. 



Double sides, Gold " . . 1 10 to 3 3 



679 Ditto ditto ditto Best Steel , 10 6 12 6 



It is not generally known that vrhat are termed " Pebbles," as used in the construction 

 of spectacle lenses, are cut from Rock Crystal. For such no better substance is obtainable 

 when free from impurities, being much harder and brighter than glass. The difficulty, 

 however, of obtaining " Pure Pebbles " is great, and not until much labour has been 

 expended in cutting and polishing can any of the many defects be discovered which 

 ultimately cause their rejection. It is in consequence of a large percentage of loss in the 

 production of " Pebble Lenses " that the cost is so much greater than glass ; but it is 

 only apparent, as the advantages of a higher polish, the non-liability to scratch or break, 

 well compensate for the outlay. 



For the information of those who sometimes imagine their Spectacles no 

 longer serviceable, Negretti & Zambra beg to say that a little expense will often, 

 for all practical purposes, make them equal to new. The re-working of a pair of 

 pebbles to a higher power, a new glass, soldering a broken frame, or a new spring 

 to an eye glass, will frequently accomplish this end. 



These repairs are executed at moderate charges and returned by post in the 

 shortest possible time from their receipt with instructions. 



Spectacles made to order of any shape or material, and fitted with lenses worked 

 to any particular form. Pebbles re-worked and altered to suit the variation of 

 sight. 



Spectacles or Eye Protectors, Gilt Plated or Nickeled, to prevent rust, at a 

 slight advance on prices quoted. 



Spectacles suited to the Sight by sending an old Lens or piece of a broken one. 



680 " SPECTACLES, WHEN TO WEAR AND HOW TO USE THEM : " addressed to 

 those who value their sight. Published by NEGRETTI AND ZAMBRA. 



Price (post-free), 6d. 



