 Implicitly referring to the equivalence of mass and energy, without explicitly mentioning either the result or Einstein by name, Cockcroft and Walton then simply assert that a mass 0.0154 amu “is equivalent to an energy liberation of \((14.3 \pm 2.7) \times 10^6\) Volts” (p. 236). They then implicitly suggest that this inferred value for the kinetic energy of the two resulting \(\alpha\)-particles is consistent with the observed value for the kinetic energy of the \(\alpha\)-particles. Cockcroft and Walton conclude that “the observed energies of the \(\alpha\)-particles are consistent with our hypothesis” (pp. 236–237). The hypothesis they set out to test, however, is not mass-energy equivalence, but rather than when a \({^7}\Li\) nucleus is bombarded with protons, the result is two \(\alpha\)-particles.