THE ETON COLLEGE ROBBERIES.-At the Bucks Quarter Sessions, at Aylesbury, yesterday (Monday), M. Ostrog, alias Bertrand Ashley, &c., was brought up charged with having committed several robberies at Eton College, and also a robbery at the barracks, Woolwich. The property stolen was of considerable value. The prisoner, who represented himself as a surgeon late of the Russian Navy, is a notorious thief and swindler. In 1863, under the name of Max Grief, alias Gosler, he was sentenced at the Oxford Assizes to ten months' imprisonment for committing a robbery in one of the colleges. In 1864, under the name of Max Sobieski, he was convicted at Cambridge as a rogue and vagabond, being found in a College for an unlawful purpose, and sentenced to three months' imprisonment. In July, 1864, the prisoner took up his residence at Tunbridge Wells, and there passed himself off as Count Sobieski. He entered into good society, and succeeded in swindling a great number of people-tradesmen and others. He was next heard of at Exeter, in December, 1864, when he was tried at the Quarter Sessions there for fraud and felony and sentenced to eight months' imprisonment. In January, 1866, he was again in custody, but was acquitted at the Glocester Quarter Sessions for fraud. He was next apprehended on several charges of felony at Chatham, when, after a desperate resistance, he escaped from the police. He was apprehended after an exciting chase. He was tried at Maidstone in July, 1869, on these charges and sentenced to seven years' penal servitude. He was released from the Chatham Convict Prison in May, 1873, when he again commenced a series of robberies for which he was yesterday tried. Visiting Woolwich barracks, he managed to get access to the quarters of Captain Milner, of the Artillery, and stole several valuable articles of silver. He afterwards took up his residence in Windsor, and his plausible address and gentlemanly appearance got him introduction to several officers there. He frequently dined with them, they having little idea that he was a returned convict. Having committed several robberies from the boys' apartments at Eton College, of silver cups, &c., he decamped, and was traced to Burton-on-Trent, where he was apprehended by Mr. Superintendent Oswell, upon whom the prisoner drew a loaded revolver, which was taken from him. The prisoner was found Guilty and sentenced to 10 years' penal servitude.