PRESIDENT'S ADDRESS. 17 



storage. Another possible source of power is alcohol, but a 

 satisfactory way of producing it in this country has yet to be 

 found. A Smoke abatement Committee has been appointed 

 by the Ministry of Health with a view to reducing the smoke 

 nuisance in our large manufacturing towns. A method of 

 building cottages formerly in use, called pise-de-terre, was by 

 ramming nearly dry earth between shutters to form a wall. 

 I have seen garden walls in Dorset which appear to be made 

 by this method and when thatched to last well, and with the 

 price of cottages at its present height, this cheaper method 

 might be adopted with advantage. One of the largest buildings 

 yet made of steel electrically welded has been erected and 

 measures 27 by 50 feet. In America ships have now for some 

 little time been fabricated from separate parts, manufactured 

 by different firms. These have shewn themselves very sea- 

 worthy, and any damages are repaired by the introduction of 

 a new standard part in a fraction of the time which would 

 otherwise be required. The raising and repairing of an Italian 

 battleship sunk in six fathoms of water by an explosion, w r hich 

 made an enormous rent, has been successfully carried out, the 

 ship being floated by compressed air, upside down, towed to a 

 dry dock, repaired, and afterwards righted at sea. The rent 

 covered more than 500 square feet. The increase of the 

 population in Egypt and the increased cultivation have made 

 increased irrigation necessary, for which a scheme is proposed 

 involving two immense dams on the Nile, one being near 

 Khartoum and having a length of more than four miles. Some 

 experiments with balloons have shewn that the most visible 

 colour for pilot ballons is red if white clouds are present, but 

 white if the sky is blue. The mean rate of ascent was 530 

 feet per minute, but the rate varied a good deal under different 

 conditions. Experiments have also been made with aviators 

 by placing them in a large tank of cold rarified air, correspond- 

 ing to different heights, and observing its effect. Different men 

 can stand different amounts of cold and rarefaction, but about 

 19,000 feet appears to be the limit and oxygen becomes 

 necessary at about 12,000 feet. However, the record height 



