Popular Science Monthly 

 To Open a Stubborn Knife- Blade, 

 Throw It From You 



THE next time the best blade of your 

 pocket-knife refuses to open when you 

 need it badly, give it a good reprimand and 

 throw it away from you. But first place a 

 corner of your handkerchief over the back 

 of the blade and wind the rest of it tightly 

 around the knife. Hold the opposite corner 

 between the first and second fingers of 

 your right hand, if you are right-handed, 

 and give vent to your annoyance in the 

 force of the throw. This will calm you con- 

 siderably and by the time you traverse the 

 distance over which you have flung the 

 knife you will be in a forgiv- 

 ing mood. When you pick 

 up the knife you will find the 

 blade opened. This is a 

 bonafide method which will 

 open the rustiest of knives 

 without injury to the finger- 

 nails. — C. S. Minter. 



907 



ne 

 receiver 



Amplifier 

 ' passage 



Adjusting screw 

 The Smallest Bandsaw — A Time and 

 Labor Saver 



THE smallest band- 

 saw ever made is 

 that recently patented 

 by John A. Carlson of 

 Seattle. Mr. Carlson 

 was impressed by the 

 need of a saw which 

 would cut close on 

 very fine work. 



His small machine 

 can be placed between 

 every two benches. It 

 is a miniature band- 

 saw which has all the 

 features of the ordinary 

 bandsaw and several 

 others of special value 

 in a pattern shop. It 

 can be set on a stand- 

 ard on the floor or at- 

 tached to a bench or 

 table. It is electrical- 

 ly operated. 



Among the unusual 

 features are safety de- 

 vices which make the 

 tool practically fool- 

 proof, a tilting table 

 with degree register 

 and a locking device. 



Above: The helmet carries 

 the telephone receiver and 

 holds the transmitter in place 



At left: Diagram of helmet 

 and of the telephone appli- 

 ances which make conversa- 

 tion in an airplane possible 



The smallest bandsaw and its in- 

 ventor. It is practically fool-proof 



Aviators Now Can Carry Their Tele- 

 phones Under Their Hats 



ANEW YORK 

 man, Jesse L. 

 Spence, has invented a 

 helmet for the use of 

 aviators which not on- 

 ly provides them with 

 a head covering but a 

 telephone as well. Any 

 one who has ever tried 

 to talk while in an 

 airplane knows how 

 difficult it is. The 

 loud noise made by 

 the engine and the 

 high wind pressure 

 make conversation 

 well nigh impossible. 

 The type of helmet 

 invented by Mr. 

 Spence has a pocket 

 which holds a tele- 

 phonic receiver, ear 

 tabs and a flaring tube 

 leading away from the 

 pocket which connects 

 with an opening inside 

 of the ear tabs. When 

 two or more persons 

 are in the airplane 

 each wears a helmet. 



