He learned how the old masters of the various schools of painting prepared a canvas or panel--how the snowy "veil" was spread and dried, how the under painting was executed in earth-red and bone-black, how the glaze was used and why, what was the medium, what the varnish. He learned about the "baths of sunlight," too--those clarifying immersions practised so openly yet until recently not understood. He comprehended the mechanics, physics, and simple chemistry of that splendid, mysterious "inward glow" which seemed to slumber under the colours of the old masters like the exquisite warmth in the heart of a gem. To him, little by little, was revealed the only real wonder of the old masters--their astonishing honesty. He began to understand that, first of all, they were self-respecting artisans, practising their trade of making pictures and painting each picture as well as they knew how; that, like other artisans, their pride was in knowing their trade, in a mastery of their tools, and in executing commissions as honestly as they knew how and leaving the "art" to take care of itself. Also he learned--for he was obliged to learn in self-protection--the tricks and deceptions and forgeries of the trade--all that was unworthy about it, all its shabby disguises and imitations and crude artifices and cunning falsehoods. He examined old canvases painted over with old-new pictures and then relined; canvases showing portions of original colour; old canvases and panels repainted and artificially darkened and cleverly covered with both paint and varnish cracks; canvases that almost defied detection by needle-point or glass or thumb friction or solvent, so ingenious was the forgery simulating age. Every known adjunct was provided to carry out deception--genuinely old canvases or panels, old stretchers really worm-eaten, aged frames of the period, half-obliterated seals bearing sometimes even the cross-keys of the Vatican. Even, in some cases, pretence that the pictures had been cut from the frame and presumably stolen was carried out by a knife-slashed and irregular ridge where the canvas had actually been so cut and then sewed to a modern _toile_. For forgery of art is as old as the Greeks and as new as to-day--the one sinister art that perhaps will never become a lost art; and Quarren and his aged mentor in the basement of the Dankmere Galleries discovered more than enough frauds among the Dankmere family pictures showing how the little Earl's forebears had once been gulled before his present lordship lay in his cradle. To Quarren the work was fascinating and, except for his increasing worry over Strelsa Leeds, would have been all-absorbing to the degree of happiness--or that interested contentment which passes for it on earth.