AcGDST 2, 1897.] 



KNOWLEDGE. 



179 



Wood, Captain Abney, and Herbert Jackson (of King's 

 College), and the results put through the dye baths, im- 

 mediately and in their presence, by a young lady represent- 

 ing the inventor. The subjects were their own — flowers 

 and fruit bought at Coveut Garden immediately before the 

 experiments. 



The position of direct natural-colour photography can 

 hardly be said to be finally satisfactory. We have the 

 indirect (three-colour) method, perfect and commercial. 

 We have formulse published, but insufficiently tested and 

 confirmed. And we have two processes of which the 

 results are shown, but around the methods of which there 

 is a veil of mystery. What has been accomplished gives 

 us hope for success as crowning further work, and I believe 

 that much is yet to be expected from the careful researches 

 of Carey Lea, applied along some such lines as are suggested 

 by Graby. 



Since the above was written a patent specification has 

 been filed by Dansac and Chassagne. This, of course, 

 should give us a full insight into the Chassagne process, 

 but, as a matter of fact, it is so complicated, so contradic- 

 tory, and so chemically impossible that it has been 

 generally accepted as a ridiculous piece of involved 

 phrasing. Even the American agents for the process have 

 acknowledged this, and point out the value of words as a 

 means to conceal thought. 



Within the last few days, too, the inventors of the 

 Chassagne process have given three or four demonstrations 

 at the Photographic Convention. In addition to the 

 selective absorption of the dyes by silver prints, the 

 demonstrator claimed that the same action would occur 

 with carbon prints. This, to photographers, seems to 

 finally dispose of any idea of chemical selection. Asked 

 whether the same result could be obtained with a half-tone 

 print (in ordinary printing ink on ordinary paper), the 

 demonstrator offered to try ; and though she was stopped 

 before completing the experiment, it went far enough to 

 show that the blue dye coloured the sky, but did not colour 

 a white horse which was the principal object. After this 

 I incline to award the credit to the operator, who paints 

 on the dyes with a set of varying brushes, rather than to 

 any " selective " power of the process. 



ANCIENT VOLCANOES OF GREAT BRITAIN.- 



VOLCANOES in Britain! How can that be ? The 

 volcanoes themselves are dead and buried — buried 

 beneath the cobwebs of antiquity ; nevertheless, 

 these ancient lights are unearthed from time to 

 time, like Roman lamps from buried cities, and 

 they tell in eloquent, though 

 silent, terms the story of their 

 infancy, matured life, and old 



Long, long ago, there was 

 in Great Britain many a trun- ../ 



cated conical mountain, topped •■•'■'■ ■.l.-^ '■", . - .-•■ 



by cup-shaped hollows com- 

 municating with the fiery 

 regions in the interior of the 

 earth. They variegated the 

 scene from the plains below 

 with their dark canopies of 

 blackest smoke and lurid noc- 

 turnal gleams of fii-e. If you possess the happy faculty 

 of imagination it may be possible to infuse new life 



• " Ancient Volcanoes of Great Britain." By Sir Archibald Geitie, 

 F.R.S. (MacmiUan.) Two T0I3. 363. 



into the dry bones — raise these old volcanoes from the 

 dead. Drawing aside the curtain which hides the past 

 history of our ancient island home, and in fancy projecting 

 our thoughts backwards to an unrecorded period, one may 

 witness the grinding and hissing murmur of the escaping 

 gases through the dread chasms of the volcanoes of the 

 Malvern HiUs ; the flashing of hydrogen with thunder- 

 like violence into Tiuion with atmospheric oxygen over the 

 Cambrian Group in Wales ; the deepening of the black- 

 ness as of night rushing upon the realm of noon, 

 encu'cling the land as with an impenetrable veil — rolling 

 on over air, earth, and sea. Looking towards Charnwood 

 Forest, you may in your mind's eye see the lightnings 

 darting to and fro iu innumerable zigzag streaks, woven 

 into a fantastic fiery gauze-like envelope and assuming 

 quaint and vast mimicries of monster shapes striding 

 rapidly across the gloom — the glow of overhanging 

 vapours, like pillars of fire, mingling with the blue 

 flames of hydrogen and sulphur, investing the scene of 

 horrible beauty with hues such as no rainbow ever 

 rivalled. Turning northwards you may behold the vol- 

 canoes of the Lake District belching forth showers of 

 ashes mixed with vast fragments of burning stones, and 

 white-hot lava welling over the craters' edges and clothing 

 the mountain slopes with liquid fire — forming in hollows 

 seething lakes. More distant still, the volcanoes of the 

 Cheviot Hills, Ben Nevis, and outwards to the West, in 

 Ireland, by a little stretch of the imagination you may see 

 simultaneous eruptions discharged into the sea. 



" The contrast between the peacefulness and beauty of 

 the ordinary landscape and the hideous warfare of the 

 elements at these times of volcanic fury, could not but 

 powerfully impress the imagination and give a colour to 

 early human conceptions of nature and religion. . . . 

 When in later centuries the scientific spirit began to 

 displace the popular and mythological interpretation of 

 natural phenomena, the existence of volcanoes and their 

 extraordinary phenomena offered a fruitful field for specula- 

 tion and conjecture. . . . By slow degrees the volcano was 

 recognized to be as normal a part of the mechanism of our 

 planet as the rivers that flow on the terrestrial surface. 

 .... They feel that their knowledge of the earth extends 

 a little beyond its mere outer skin, and that the mystery 

 which still hangs over the vast interior of the planet can 

 only, if ever, be dispelled by the patient study of these 

 vents of communication between the interior and the 

 surface." Towards the solution of this problem what can 

 the volcanoes of our island contribute ? Not a single 

 crater anywhere remains, save where it has been buried 

 under lava. What of the original cones'? They have 

 perished, and the most telling evidence of old volcanoes 



Fro. 1. — Effects of Denudation in a Vcsuvian Cone. 



that remains to us is only to be found in the materials 

 which they have left behind. All this scattered evidence 

 of the awe-inspiring objects which once diversified the 

 surface of our land, has been brought together by the 



