The Corporation of London, moved thereto by a letter from the Lord Chief Justice, and not unnaturally alarmed themselves at the ravages of a pestilence which spared neither Lord Mayor nor aldermen, set about inquiring into its origin. A committee was appointed for this purpose in October, 1750, five months after the last outbreak, and their instructions were to ascertain "the best means for procuring in Newgate such a purity of air as might prevent the rise of those infectious distempers." . . . The committee consulted the Rev. Dr. Hales and Dr. Pringle, F. R. S., and the latter subsequently published a paper in the "Transactions of the Philosophical Society," containing much curious information concerning the disease. The remedy suggested by Dr. Hales, and eventually approved of by the committee, was to further try the ventilator which some time previously had been placed upon the top of Newgate. Nothing less than the reconstruction on an extended plan of the prison, which was acknowledged to be too small for its average population, would have really sufficed, but this, although mooted, had not yet taken practical shape. The existing ventilator was in the nature of a main trunk or shaft, into which other air-pipes led from various parts of the prison. But these were neither numerous nor effective, while there was no process of extraction or of obtaining an updraught. To effect this a machine was erected upon the leads of Newgate with large arms like those of a windmill. Nevertheless, throughout the execution of the work and afterwards the air of Newgate continued pestiferous and fatal to all who breathed it. The gaol fever or its germs must indeed have been constantly present in Newgate. The more crowded the prison the more sickly it was. The worst seasons were the middle of winter or the middle of summer, or when the weather was damp and wet. The place was seldom without some illness or other; but in one year, according to Mr. Akerman, about sixteen died in one month from the gaol distemper. Mr. Akerman declared that the fever was all over the gaol, and that in ten years he had buried eight or ten of his servants. He also gave a return to the Commons' committee, which showed that eighty-three prisoners had died between 1758 and 1765, besides several wives who had come to visit their husbands, and a number of children born in the gaol. This statement was supported by the evidence of the coroner for Middlesex, Mr. Beach, who went even further, and made out that one hundred and thirty-two had died between 1755 and 1765, or forty-nine more in the two additional years. In 1763 the deaths had been twenty-eight, all of them of contagion, according to Mr. Beach, who was also of opinion that a large percentage of all the deaths which had occurred were due to the gaol fever.