DRINKING WATERYear: 1907Price: £10Number in set: 6THE MAKING OF FIREYear: 1908Price: £13.5Number in set: 6LIGHTING THROUGH THE AGESYear: 1909Price: £11.5Number in set: 6WATER UTILISATION IN ANCIENT WORLDYear: 1924Price: £13.5Number in set: 6DROPS OF WATER UNDER A MICROSCOPEYear: 1931Price: £6Number in set: 6FIRE AMONG PRIMITIVE PEOPLEYear: 1940Price: £6Number in set: 6