viii Preface 



present volume is intended simply to place at the disposal of 

 all science teachers an experience gained at considerable cost, 

 both in time and trouble, and to aid a teacher who has original 

 methods of teaching science and who wishes to present his 

 subject in as fresh and personal a way as possible, to overcome 

 the mechanical difficulties that at present hinder the realization 

 of his desires. It is hoped that the brotherhood of science 

 teachers will accept this effort in such spirit, that they will 

 criticize where necessary, and so help in the production of a 

 more useful volume, and consequently to an enhanced efficiency 

 of science teaching. No mere book-work can completely 

 fulfil the purpose for which this volume is designed, particularly 

 in the case of glassworking, which is mainly a matter of 

 experience. 



All science teachers should go through a course of practical 

 work in at least the three principal materials considered in 

 this book a few minutes' instruction, and the supervision 

 and criticism of work by an expert while it is progressing 

 being worth hours of patient research upon the bench, and 

 being far less destructive to one's patience. Courses of this 

 character are now organized in Ireland by the Department of 

 Agriculture and Technical Instruction, and in England more 

 recently by the Educational Handwork Association, in each 

 case at times and centres convenient of access to teachers, and 

 indications exist that other progressive educational bodies are 

 about to follow upon similar lines. The result must be a 

 quickening of interest on the part of teachers able for the first 

 time to construct their own special apparatus, and therefore 

 encouraged to research upon new methods of demonstration ; 

 at the same time a material reduction of the cost of repairs 



