Sounds like a pretty weak cypher by todays standards. 90 million combinations seems like it would be fairly easy to brute force. Still, it's interesting to see that some of his ideas, like row operations on matrices, are still used in some crypto algos today.
Indeed, by todays standards it's pretty weak. Then again, 200 years is a long time, and back in the day all the grunt work had to be performed by humans instead of computers. Brute forcing was not a realistic possibility.
