At a meeting of the Chicago Temple Sons of Liberty, on the eve of the Convention, we heard for the first time (and that from the mouth of L.A. Doolittle), a definite plan for the attack of Camp Douglas. Doolittle told how the camp was situated, and that it was accessible on two sides; that guns were in position on only one side, and the west side was referred to by him as being the weakest; he spoke of the common board fence which formed the enclosure, and of the ease with which the camp could be taken, and the vast importance of liberating the prisoners the first thing upon an uprising. The speech of Doolittle was variously received; many of the members were much interested; others who were in the higher degrees of the order were vexed beyond measure that Doolittle should be so stupid as to proclaim, in this public manner, a matter which really belonged to higher degrees of the organization to decide. One of the number, James Geary, a second-hand clothes dealer and broker on Wells street, who will receive further mention by and by, became so much incensed that he ordered Mr. Doolittle to his seat, declaring, with an oath, that Doolittle was telling too much. At a meeting about this time, several of the members spoke upon the subject of releasing the prisoners at Camp Douglas. A map of Camp Douglas was exhibited by an individual present, who seemed to be a soldier. The map was a fine piece of work and had been made by a hand accustomed to such labor. Upon this map the precise position of the various departments, headquarters, cannon, &c., were laid down. There could be no shadow of doubt in the mind of any man not stupefied with whiskey, and possessed of common sense, that the details of the attack had been carefully considered by those who were most interested in leading it on. It had for some time been the policy of the Sons of Liberty to unite with the Invincible Democratic Club and the various McClellan escorts in the city and elsewhere, and seek to become its officers, that in case of an outbreak it would be far better to be the controlling power, than to be controlled. This plan worked admirably, and the Democratic Invincible Club of Chicago became one of the most corrupt organizations outside the order of Sons of Liberty. Its secretary at one time was Charles W. Patten, who had been a Grand Seignior of the Chicago Temple, was also a member of the Grand Council, and had taken a very active part in the prosperity of the order, and was chairman of the committee to see that all the Sons of Liberty were armed. One of the officers of the above named Club was Capt. P.D. Parks, whose devotion to Jeff. Davis and good whiskey were noticeable features in his character. This Capt. Parks was captain of the Invincible Club and often made speeches in the Sons of Liberty Hall.