The art of cutting gems, it is true, was at that time well understood, but no one had attempted to drill a hole in a hard stone fine enough for a properly sized pivot. The watches at that time that were jewelled could boast of nothing more than the balance holes, and they were not pierced to let the pivot _through_. It is a very difficult matter to polish a taper indentation in a stone, even with modern appliances, in consequence of the tendency to create a _tit_ at the bottom,--thus throwing the balance staff out of upright. The difficulties in the then state of knowledge retarded the general introduction of stone-work for many years. The Swiss, however, seeing the advantages derived, finally struck out the various manipulations with success. Time and experience gave more skill, and at the present time it is impossible to find a Swiss watch, even of the cheapest class, that is not jewelled in at least four holes. The English trade adopted the art later; but even then it did not become general for many years. Within a generation, only fine English levers were jewelled. The mere substitution of a harder substance was not the only improvement; other conditions necessary to accuracy were insured. The hole could be made _round_--the material of such a character that no chemical action could be effected on the oil used for lubrication, and the vertical section of the hole could be made so as to present the least amount of frictional surface, yet still giving a perfectly polished bearing, thus avoiding the cutting of the pivot. The whole “_modus operandi_” from the stone in the rough to the last setting up is well worth the attention of the watch repairer, and certainly that of the manufacturer.