Here's a PDF with the original publication: https://ia601600.us.archive.org/32/items/philosophical-magazine-and-letters_1950-03_41_314/philosophical-magazine-an

Here's a PDF with the original publication: https://ia601600.us.archive.org/32/items/philosophical-magazine-and-letters_1950-03_41_314/philosophical-magazine-and-letters_1950-03_41_314.pdf#page=50 https://ia601600.us.archive.org/32/items/philosophical-magaz...