"Not content with playing the part of a mere inventor, Hales added to that role... philanthropist, for seeing that it would be of great benefit to humanity, he wrote constantly on the subject and used what influence he had to obtain the introduction of his ventilators. Success crowned his efforts. In a few years his ventilators had been put not only into Newgate and the Savoy prison, but also into the Winchester Gaol, the Durham County Gaol, then the Gaols of Shrewsbury, Northampton and Maidstone. The results were remarkable. During the first four months after their introduction into Newgate, the death rate was reduced by more than fifty per cent, while in the Savoy prison the rate fell from fifty or a hundred per annum to one or two per annum. Equally gratifying were the results at the smallpox hospitals. ...here the mortality was soon reduced to two-thirds of what it had formerly been."