The Primeval Lead Isotopic Abundances and the Age of the Earth's Crust

Nier's determinations of lead isotopic abundances in common lead ores have been the subject of considerable study in connection with attempts to calculate the age of the earth. The importance of the age of the earth in fixing the age of the elements has led us to remark on the very high precision frequently attributed to the former age determinations. A calculation is presented which yields a rough maximum age of the earth, namely, $t\left(max\right)=5.3\mathrm{}$ billion years. The primeval lead isotopic abundances have been estimated and briefly discussed in the light of nuclear systematics.