the geese in England could supply of quills in a year, a matter of 

 no inconsiderable importance in these days of universal education. 



In connection with the subject of gun-making is that of ex- 

 plosives for guns. It has been proved that those explosives 

 which furnish the largest proportion of gaseous products, and 

 whose explosion is attended by the smallest amount of heat, exerts 

 the least erosive action on the inner surface of the gun. To com- 

 bine these desiderata with the property of a smokeless powder 

 has been for some years the aim of many practical chemists, but 

 although many kinds have been invented and tried with partial 

 success, such as the nitro-cellulose powder of Colonel Schultze, 

 and the mtro-glycerine powder of Mr. Nobel, none is entirely 

 satisfactory, the almost insurmountable difficulty being to produce 

 a powder which shall remain free from chemical changes when 

 exposed to extreme variations of temperature. Some months ago 

 an experiment was made in London with the Giffard gun, in 

 which liquified carbonic acid gas is used as the expulsive agent. 

 The liquid is contained in a small steel magazme attached to the 

 under-side of the gun, and is suf&cient to discharge three hundred 

 shots. The charge of liquid for each round is contained in a 

 special chamber, and is released by the pulling of the trigger. 

 The bullet is dropped separately into an orifice in the breech 

 block. The pressure of the fluid in the magazine is five hundred 

 pounds to the square inch. There is no heating of the barrel by 

 this new propelling force, nor is there any erosion of the inner 

 surface of the gun, and merely a slight vapour, which instantly 

 fades away, is noticeable when the gun is discharged. 



Although considerably behind either France or America in the 

 use of the telephone, we are rapidly increasing our means of 

 telephonic communication with our friends in the United King- 

 dom, and it is hoped that before many weeks have elapsed the 

 telephonic cable between London and Paris will be completed. 

 The line will be laid via Maidstone, Ashford, Folkestone, Dover, 

 and St. Margaret's Bay to Calais. Messrs. Siemens are the 

 electrical engineers to the line, which is the first real submarine 

 telephonic cable in existence. The number of telephones now in 

 use in this country is ninety-nine thousand, and in America they 

 have reached the immense number of over two hundred and 

 twenty thousand. Only thirteen years have elapsed since the 

 telephone was first employed as a practical apparatus, and there 

 are now upwards of one million telephones in working order 

 throughout the world. 



A new species of mechanical telephone has lately been invented 

 by Mr. Mellett, of Massachusetts, in which electrical agency is 

 altogether discarded. This instrument, which is called the " Pul- 



