Preface vii 



In addition to the difficulties of construction and repair, 

 there are endless problems which worry the teacher in charge 

 of laboratory work. The cleaning of mercury, the re-silvering 

 of a galvanometer mirror, the loosening of burette stoppers, 

 are details which are almost constant sources of trouble and 

 annoyance to the teacher, and of loss of time to the class. 

 The removal of these must make for increased efficiency and 

 more comfortable teaching conditions, and it is hoped that 

 the fourth section of the book will do much toward this 

 desired end. 



It is hoped also that the exercises given in this book may 

 be of use to those teachers who wish to make a practical 

 contribution to the co-ordination of manual training and 

 science. All teachers know the difficulty of finding inte- 

 resting exercises in manual work for boys, and simple 

 apparatus lends itself remarkably well to this end. Model 

 turbines, wheel barometers, steam heaters, steam and water 

 jackets for eudiometers, etc., are well within the possibilities 

 of an ordinary schoolboy after two or three years at manual 

 training in wood and metal, and the equipment of a laboratory 

 may be materially strengthened by a co-ordination between 

 these departments, without detriment to the educational value 

 of either indeed, with positive profit to both. 



It may be stated that the present volume is written without 

 extensive reference to contemporary text books. It is placed 

 upon the market as a record of the author's experience during 

 some twenty years of practical laboratory teaching in almost 

 all grades of educational endeavour, and it is hoped that it may 

 be accepted in that light. Other methods than those herein 

 described exist ; other processes give excellent results. The 



