_Pittsburg, March 13, 1851._ RICHARD GARDINER was arrested in Bridgewater, Beaver County, Pennsylvania, claimed as the property of Miss R. Byers, of Louisville, Kentucky. Judge Irwin, of the United States District Court, "remanded the fugitive back to his owner." He was afterwards bought for $600, and brought into a free State. _The Wilmington (Del.) Journal_, in March, 1851, says kidnapping has become quite frequent in that State; and speaks of a negro kidnapped in that city, on the previous Wednesday night, by a man who had been one of the city watchmen. THOMAS SIMS, arrested in _Boston_, April 4, 1851, at first on pretence of a charge of theft. But when he understood it was as a fugitive from slavery, he drew a knife and wounded one of the officers. He was taken before Commissioner George T. Curtis. To guard against a repetition of the Shadrach rescue, the United States Marshal, Devens, aided by the Mayor (John P. Bigelow) and City Marshal (Francis Tukey) of Boston, surrounded the Court House, in Boston, with heavy chains, guarded it by a strong extra force of police officers, with a strong body of guards also within the building, where the fugitive was imprisoned as well as tried. Several military companies also were called out by the city authorities, and kept in readiness night and day to act against the people, should they attempt the deliverance of Sims; Faneuil Hall itself being turned into barracks for these hirelings of slavery. Every effort was made by S.E. Sewall, Esq., Hon. Robert Rantoul, Jr., and Charles G. Loring, Esq., to save Sims from being returned into slavery, and Boston from the eternal and ineffaceable disgrace of the act. But in vain. The omnipotent Slave Power demanded of Boston a victim for its infernal sacrifices. Millard Fillmore, Daniel Webster, and their numerous tools, on the Bench, in Commissioners' seats, and other official stations, or in hopes of gaining such stations bye and bye, had fallen upon their faces before the monster idol, and sworn that the victim should be prepared. Thomas Sims was ordered back to slavery by Commissioner G.T. Curtis, and was taken from the Court House, in Boston, early on the morning of April 11th, [1851,] to the Brig Acorn, lying at the end of Long Wharf, and thence in the custody of officers, to Savannah, Georgia. There, after being lodged in jail, and severely and cruelly whipped, as was reported, he was at length sold, and became merged and lost in the great multitude of the enslaved population. The surrender of Sims is said to have cost the United States Government $10,000; the City of Boston about as much more; and Mr. Potter, the claimant of Sims, about $2,400, making a total of some $22,000, directly expended on the case.