Newton commanded three voyages, not two, and nowhere in his "Thoughts on The African Slave Trade" does he claim that he lost only six slaves.

It is beyond belief that he could have sailed from the West Coast of Africa with a cargo of 250 slaves (which he did on his second voyage) and lost only six slaves.

It is, I suppose, possible that his final voyage with only 87 slaves could have been completed with zero mortality.

I think we need input on this thread from someone who has actually studied the original source material.