BAIRD &TATLOCK (LONDON) LTD. 





No 7 Siphonage Model. Consisting of one W.C. fitted to soil pipe (in glass) with siphon 

 flushing cistern, fitted to wooden stand. The action of valve or wash-down closets 

 and all phases of siphonage and anti-siphonage can be demonstrated. In box 



No. ii. Water Pollution. A most interesting model, devised to show how water in 

 high pressure service pipes (when running full bore) takes in sub-soil water and air. 

 This will be found a most valuable addition for Teachers of Public Health 



No. 12. Ventilation. A model designed to show how air is vitiated by combustion by 

 the evolution of CO 3 and several interesting facts about ventilation. This model 

 shows the valuelessness of excess of height in a building, and the necessity of inlets 

 and outlets for proper ventilation. Full particulars sent for demonstrating these 

 points 



No. 13. Hinckes Bird's Window. A double-sashed window, 2 ft. 6 in. by i ft. 6 in., to 

 illustrate the simple method of fresh-air inlet without draught, as suggested by 

 Dr. Hinckes Bird 



No. 15. Air Inlet (Ellison's). This model illustrates in a simple way the effect produced 

 by Ellison's air brick on a current of air, transforming it from a keen draught into 

 a diffused and comfortable flow. It consists of an air brick, bellows, and indicator. 

 Fitted on a neat wooden stand 



No. 16. Louvre and hit and miss Ventilators (Cooper's). Working models in frames 

 fitted on mahogany stands . . . . . . . . each 



No. 17. Dampness and its Prevention. This model gives a practical illustration of 

 the effect of damp and the best method of preventing the same. It consists of three 

 piers- of brickwork, one built without, and the others with damp-proof courses, and 

 a zinc tray. When the brickwork is placed in the tray and water is supplied to the 

 base, the one pier becomes discoloured and illustrates how water rises in walls by 

 capillarity, the others remain perfectly dry above the damp-proof courses. This is 

 a most valuable model for permanent exhibition 



No. 18. Capillarity. Glass model for illustrating the law referred to in above description 



No. 19. Siphonage. Two glass models illustrating the action of a simple bent siphon 

 and an annular siphon . . . . . . . . . . . . each 



No. 20. Force Pump. Glass working model showing the action of raising water from a 

 well and forcing it upwards into a cistern. Price 4/-, or on stand with well 



No. 21. Ordinary Lift Pump. Glass working model. Price 3/6, or on stand with well 



No. 22. Water Absorption. This model demonstrates the amount of water absorbed by 

 an ordinary brick 



No. 23. Hardness of Water Test. Set of simple apparatus for determining the degrees 

 of hardness in any water, easily manipulated. With full description 



No. 24. Clothing. Apparatus to demonstrate the heat retaining properties of clothing 

 materials. Specimens of cotton, silk, wool, and cellular cotton are included for 

 comparisons 



No. 25. Air Permeability. Apparatus to demonstrate the ease with which air passes 

 through an ordinary brick. The passing of the air is made visible by the introduction 

 of a water trap 



1 12 6 

 220 



10 

 220 



1 15 

 1 10 



3 15 

 036 



020 



086 

 076 



2 10 

 15 



1 10 

 150 



CROSS STREET HATTOTST GARDEN, E-C 



1094 



