60 Original Articles, [Jan. 
produced a most remarkable paper on Earthquakes to the Royal 
Society, printed in the ‘ Philosophical Transactions,’ vol. li.—atten- 
tion being then powerfully directed to the subject by the recent 
terrible shock that had destroyed Lisbon. 
He shows a wonderfully clear conception, for his time, of the general 
configuration and structure of the superficial parts (or crust as it is 
the fashion to call it) of the Earth, and of the relations between Vol- 
canoes and Earthquakes. Both, he supposes, are due to vapour of 
high tension almost instantly generated by contact of water with in- 
candescent rock, deep in the earth. Misled, however, by his concep- 
tion of the universality of horizontally disposed strata, and of a 
nucleus of liquid lava universally beneath them, he goes at last hope- 
lessly wrong, by supposing that Harthquake-shock consists in a liquid 
wave of translation produced in the lava sea beneath, which forces, as 
it travels, the flexible covering of stratified material overhead to undu- 
late along with it, just as ‘‘a large carpet spread upon a floor, if it be 
raised at one edge, and suddenly brought down again—the air under 
it by this means propelled, will pass along until it escapes at the oppo- 
site side, raising the cloth in a wave all the way it goes.” This paper 
though vitiated throughout by this leading fallacy as to the nature of 
the Earthquake wave, was a most meritorious performance, and had 
important effects (though little specifically noticed), in moulding the 
thoughts of the earlier schools of Geclogy. 
Bertrand, Bouguer, Ulloa, Dolomieu, Grimaldi, Hamilton, and the 
Neapolitan Royal Commissioners, accumulated a mass of facts (and, 
let us add, of fictions) of Earthquakes, in the last and beginning of 
this century. 
Humboldt added to the facts in his Personal Narrative, &e. ; but 
nowhere, net even in ‘ Cosmos,’ does he show that he had any clear 
notion of what is the nature of Harthquake motion—or how produced. 
In 1835, the Comte Bylandt de Palstercamp, in an extremely curious 
though wild and imaginative work, “a Théorie des Volecans,” 
attempts to build up a sort of Cosmogony from considerations of the 
relations and reactions on our planet, of light, heat, electricity, &c., 
&e.— from these come Volcanoes, and from the latter Earthquakes. 
Truth and quasi-truth are wildly and incoherently mixed in his book. 
Shocks or blows produced by and transmitted through cavities, lifted 
up and down by sudden filling or emptying of aériform fluids, form 
Bylandt’s shock,—and starting from the following extraordinary pro- 
positions, “les effets des tremblements de terre sont toujours contra- 
dictoires aux causes qui les produisent et dirigés dans le sens inverse,” 
—‘Jeffet sera celui d’un pendule, c’est-a-dire contradictore entre les 
deux extrémités,” he arrives at the true conclusion, that bodies over- 
thrown at opposite sides of a seismic focus will all fall towards it, but 
in opposite directions to the shock and to each other. We now know 
that this is only true if the bodies fall in the first semiphase of the 
wave. Had Bylandt followed this out, and curbed his tendency to 
mysticism, he would in all probability have been the creator of Seis- 
mology,—the true discoverer of Earthquake dynamics—as it was, he 
missed the prize. 
