First, the saw will run out of true Circumferentially, and therefore out of balance, and the high side of the saw will be called upon to do more cutting duty than the low side.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
In the longitudinal direction, for most woods, it is almost negligible, being from 20 to over 100 times as great Circumferentially as longitudinally.
"Seasoning of Wood"
Joseph B. Wagner