-"The vine was violently agitated while under the closest scrutiny from root to tip, nor did their combined strength applied to the trunk serve to still it." To whom "their" refers? They who tried to steady the vine. - "After an hour's observation they retreated, no less wise, it is thought, than when they had come." What does "no less wise" mean? They were not less wise afterwards. They were as wise, or more wise, afterwards. -"But in the ensuing excitement as many courses of action were proposed as there were incapable counselors." What does the whole sentence mean? Something was exciting after whatever had happened. Actions were proposed - I guess related to whatever happened. (Probably) Each councelor suggested a different action = there was no concensus. as many actions - as - counselors The writer considers the counselors incapable.

"Their" refers to the people who try to still the vine with their combined strength. Who exactly cannot be found in this sentence. "No less wise" is equal to "not having gained any information" "But there emerged excitement as many things to do (to solve the problem at hand) were proposed because (it is obvious and this is the proof that) they were not good advisors." The original sentence longs for more context. This is the meaning, though.