According to a calculation made by P. Frech in 1900, on the basis of the then rate of production, the coalfields of central France, central Bohemia, the kingdom of Saxony, the Prussian province of Saxony and the north of England, would be exhausted in 100 to 200 years, the other British coalfields, the Waldenburg-Schatzlar and that of the north of France in 250 years, those of Saarbriicken, Belgium, Aachen and Westphalia in 600 to Boo years, and those of Upper Silesia in more than 1000 years.
Recent discoveries of vertebrates are of the same significance, the most primitive fishes being traced to the Ordovician or base of the Silurian, 2 which proves that we shall discover more 2 Professor Bashford Dean doubts the fish characters of these Ordovic Rocky Mountain forms. Frech admits their fish character but considers the rocks infaulted Devonic.
1831), followed by Frech, Canu, de Lapparent and others.
Frech, " Die karnischen Alpen," Abh.
Frech, "Die geographische Verbreitung and Entwickelung des Cambrium," Compte Rendu.