v BELIEF AND EVIDENCE 123 



of the phenomena is completely inaccurate. During an 

 eruption there is practically no flame, and certainly 

 none that can be seen except close to the crater ; no 

 smoke such as issues from a chimney is ever produced ; 

 and there is no burning in the ordinary sense of com- 

 bustion as in a fire. These elementary facts have been 

 taught to thousands of school children for the past 

 twenty years, yet popular writers and journalists seem 

 still to be unaware of them. 



A volcanic eruption may be compared not inaptly to 

 a series of boiler explosions. The dense clouds projected 

 from the vents at each paroxysm of the eruption consist 

 of steam and fine dust, and the light of the molten rock 

 in the crater flowing down the flanks of the volcano 

 as lava streams, illuminates the clouds so brilliantly as 

 to give the appearance of flames. As the lava flows it 

 also emits water vapour copiously and seems to burn 

 and smoke, though what looks like smoke is really 

 steam, and the flame is reflected light. Whatever may 

 be the ultimate cause of volcanic action, the sudden 

 transformation of water into vapour is the active agent 

 of an eruption, and by far the most abundant product 

 ejected is steam. A few inflammable gases are pro- 

 duced, and as they burn they give rise to true volcanic 

 flames, but their pale and flickering light cannot easily 

 be distinguished when a volcano is in active eruption. 



It may be too much to expect men of letters to 

 possess an elementary knowledge of science, or to have 

 any sympathy with scientific precision, but it is not 

 unreasonable to ask for accuracy of description when 

 they are dealing with natural facts and phenomena. 

 They may reply that Shakespeare was often at fault in 

 matters pertaining to natural history ; but he at any 

 rate reflected in his works the best knowledge of his 



