Our results on the momentum spectrum under 7.2 kg cm-2 of rock have been extended to lower momenta in order to test the expected rate of momentum loss in the rock. The low-momentum spectrum is quite sensitive to this. Taking the results together with our previous ones, the spectrum agrees over the whole range of momentum from 250 MeV/c to 200 GeV/c with the sea-level spectrum when due allowance is made for momentum loss. The correct form of collision loss gives much better agreement than a constant momentum-loss approximation but inclusion of other forms of energy loss is immaterial for our spectrum. The intensity at greater depths corresponding to energies up to 500 GeV is shown to be higher than can be expected on any reasonable assumptions about energy loss. Attention is drawn to the large uncertainty in nuclear energy loss at energies > 1000 GeV and the difficulty, as a result of this, in deducing the spectrum from intensity measurements deep underground.