in the public lighting of Waterloo Road in 1879. In another the products of combustion are brought down in a flue fastened round the burner, so as to heat the air which supports the combustion as it passes in pipes through the flue above mentioned to the flame; while a third kind has an arrangement for admitting separate currents of cold air to keep the chimney cool. There seems little doubt that the argand lamp will play a leading part in the gas lighting of the future. An important point connected with the use of gas is that the heat generated by combustion, may be made to do the work of ventilation, as in the fish-gill ventilator invented by the late Goldsworthy Gurney. In this strips of calico are nailed, by the two upper corners, across an opening in the wall, in such a way that each strip laps over the strip next below it. This contrivance, opening and closing like the gills of a fish, is self-acting, as the heated air passes away through the porous material, and cold air is admitted without draught. Gas is often accused of heating the rooms; but if persons, when burning candles would increase the number of the candles so as to equal the light of the gas-flame, the heat given out would be found to be less when burning gas than when burning lamps or candles. [Illustration: 49. Stott’s Governor.] It is very beneficial to regulate the pressure at which gas reaches the burners, and many complaints of impurity of the air of a room, caused by gas, arise from this want of regulation of pressure. It can be attained by the use of a governor, placed either at the meter or in proximity to the light itself. These are of many forms. Those adapted for placing near the meter are Stott’s, Fig. 49 (174 Fleet Street, E.C.), Parkinson’s, Fig. 50 (Cottage Lane Works, City Road), Strode’s, Fig. 51 (67 St. Paul’s Churchyard), Hargreaves and Bardsley’s (Hobson Street, Oldham), Hulett’s, Fig. 52 (55 High Holborn), Peebles’ (Tay Works, Edinburgh), and Smith’s (130 Fleet Street). Self-regulating burners are the “Christianson,” made by Sugg (Grand Hotel Buildings, Charing Cross), and those made by Bolding--Heran’s patent--(South Molton Street, Oxford Street), Milne, Sons, and Macfie (2 King Edward Street, E.C.), Parkinson (Fig. 53), Peebles, and Kinnear (91 Finsbury Pavement). A little steel blade, costing only a penny, is made by W. H. Howorth, Cleckheaton, Yorkshire, for use on 2-holed burners, which has the effect of silencing a roaring flame and increasing the luminosity. Another contrivance having some of the effects of a regulator, augmenting the light and consuming the smoke (therefore lessening the contamination of the air), is the Spencer Corona, Fig. 54 (3 Hyde Street, New Oxford Street), fitting closely on the top of ordinary gas globes. [Illustration: 50. Parkinson’s Governor.] [Illustration: 51. Strode’s Governor.] [Illustration: 52. Hulett’s Governor. 53. Parkinson’s Burner.] [Illustration: 54. Spencer Corona.]