PREFACE. 



SIR WILLIAM SIEMENS in his will expressed the wish that 

 his scientific papers should be published in a collected form, 

 and his Executors entrusted the task of editing them to 

 Mr. E. F. Bamber, who had been the private secretary to 

 Sir William Siemens for the last ten years of his life. 



With a view of showing more fully what a variety of 

 subjects iSir William had thoroughly grasped, extracts 

 from the discussions of learned Societies have been added, 

 which show in many cases the independent and individual 

 point of view from which Sir William Siemens regarded 

 even familiar subjects. 



The papers have been divided, according to their subjects, 

 into three volumes, dealing with 



HEAT AND METALLURGY (Vol. I.), 



ELECTRICITY AND MISCELLANEOUS SUBJECTS (Vol. II.), 



ADDKKSSKS AND LECTURES (Vol. III.), 



being arranged in each volume in chronological order, and 

 much care has been bestowed upon making the index really 

 useful. 



