I left no stone unturned when reading this "Handling the rock" section, which enabled me to spot an error. This is yet another example of the limitations of spell check. In a case such as this, spell check, much like a bible to an atheist, is useless.
The ratio of correct words to incorrect words in this section isn't too shabby. It's 51 to 1, in fact. Did you find the lone incorrect word? It's ration. The word we were looking for is ratio.
With an n at the end, we have a term most associated with daily food allowances. Remove the n and we have the relationship in quantity between two or more things. Similar spellings. Different meanings. For spell check, that spells trouble.