This is not to say that astronomical factors have played no part in glaciation. That they did not do so would be incredible. But it is to say that Mr. Wells still takes for granted in this year of grace 1926, and states as facts, theories which the average educated man knows to have been exploded as long ago as the nineties of the last century. Mr. Wells suffers, in this connection, from another fault besides that of stating the old and exploded theories of his youth as facts. He also affirms as fact what is doubtful. Thus he builds a whole series of assertions (p. 154) on the—at first sight—apparently obvious, but, in fact, much disputed idea that as the ice receded the sea-level rose. It is clear that the melting of great quantities of ice would, other things being equal, raise the sea-level. It is also presumable, on the isostatic theory, that the earth rose when and where relieved of ice pressure (the raised beaches seem proof of this). That—other things being equal—would mean a _lowering_ of sea-level when the ice melted (thus the highest-known raised beach of glacial times in America indicates a _fall_ of the sea-level since the ice melted by nearly 700 feet). Which of the two factors predominated? Only observation of such phenomena as raised beaches, fossils, submerged forests, etc., can decide, and the matter is still debated. Boule in 1906 affirmed a high sea under glacial conditions. The periods of high glaciation were, according to him, the periods of high sea-level, and the interglacial epochs the periods of low sea-level. Wright (in 1914) inclines to the opposite. The Scandinavian observers noted in one locality a rise of sea-level at the first receding of the ice, then a lowering of it. The latest opinion is mainly in favour of a rise in sea-level since the last Ice-age. Coleman, the last authority, tentatively suggests a rise. But to affirm a rise as proved is bad science. In these and many other points Mr. Wells is evidently a man confusing theory with fact. However, the few things really known by him about Pre-history are very well put. The narrative is straightforward and a fair summary. It is also to Mr. Wells’s credit that, unlike his fellow disseminators of popular “science,” he frequently uses in this section, as elsewhere, those qualifying words which distinguish fact from probabilities or doubtful possibilities. He has “may,” “probably,” and “it would seem,” where many another of his sort would have written “did,” “was,” “certainly.” But what might here have been of excellent effect in ridding uninstructed people of their dogmatism is more than neutralized by too much positiveness in diagrams and riotous make-believe in pictures.