which assume that apartments containing given cubic feet of space are all that is requisite for life and health, whereas if a spacious drawing-room be completely closed against the admission of air, an inhabitant confined to it would in time be stifled, whilst, by active ventilation or change of air, men working in connexion with diving-machines live in the space of a helmet, which merely confines the head. In the majority of instances of the defective ventilation of schools, the pallid countenance and delicate health of the schoolboy, which is commonly laid to the account of over-application to his book, is due simply to the defective construction of the school-room. In the dame schools, and the schools for the labouring classes, the defective ventilation is the most frequent and mischievous. _Mr. Riddall Wood_, an agent of the Manchester Statistical Society, thus describes some of the crowded schools found in the course of examinations, from house to house, of the condition of the town population in Manchester, Liverpool, Leeds, Hull, and York:— “I may mention that in one school where the average attendance was, I think, 36, not above eight children were present. Upon my inquiring of the mistress as to the reason, she stated that the remainder of her scholars had been taken with the measles. I perceived a bed in the school-room, upon which lay a child much disfigured by that complaint. Another child of the mistress had died of the measles. I had reason to believe that the contagion had been communicated originally from that child, because the cases of the scholars all occurred subsequently. In a school in Liverpool, having above 40 scholars in average attendance, I found the number diminished to somewhere about 10. On inquiring into this case, I ascertained that it arose from the prevalence of scarlet fever, and the master made this remark: ‘It is a very strange thing how this fever should have attacked almost all the children coming to my school, whilst none of my neighbours have got it.’ I attributed that to the very crowded state of the school. The room was very low. When the whole of his scholars were in attendance, it must have been excessively crowded. There was no thorough ventilation. “I found that in many of the schools there were from 20 to (in some cases) nearly 100 scholars crammed into a dirty house or cellar, without air or ventilation, the effluvia from whose breath and clothes was exceedingly offensive, and must, I am sure, be very injurious to the children’s health. In most of these places, too, I have found that the ordinary household occupations have been carried on by the old women.” Another inquirer states, that in the neighbourhood of Bolton he saw 70 scholars cooped up in a badly ventilated room not 12 feet square. _Bad ventilation and overcrowding of private houses._