1010 



SEC. 19. EDUCATIONAL APPLIANCES. 



Wide tube, graduated tube, and ther- 

 mometer for Gay-Lussac's appa- 

 ratus. 



Bulb and thermometer for Dumas' 

 apparatus. 



Hofmann's tube for steam, with glass 

 worm and stand. 



Cabinet with 26 bottles. 



Glass tube, two nitrogen bulbs, and 

 piece of india-rubber tubing for 

 organic analysis apparatus. 



Four weighing bottles for desiccators. 



Twelve small tubes for Eggertz's 

 carbon apparatus. 



One nest of six beakers with spouts. 

 One nest of 12 beakers without 



spouts. 



Two tin sand baths. 

 One Bink's burette 500 cc., on wood 



stand. 



Ritchie's photometer. 

 Glass carbon and porous cells for 



Bunsen's battery, 10 each. 

 Wooden burette stands (5). 

 Stand for eight burettes. 

 Bath for Eggartz's carbon test. 

 Bunsen's clamp stand. 

 Regulator for Bunsen's water bath. 



4026. Th. Miiller's Di-Electric Machine, with accessory 

 apparatus, viz. : 



Electric tuft. 

 Electric turbine. 

 Electric puppet-dance. 

 Electric peal of three bells. 

 Lightning tube. 

 Lightning conductor. 

 2 electric excitors. 

 Electric pistol. 

 2 condenser jars. 



Kgl. Preuss. Oberbergamt, Breslau. 



This machine has of late been much used in elementary schools in 

 mining districts of Germany for instruction of the children in some parts of 

 their future calling. With 12| inches diameter of disc, it gives sparks over 4 

 inches long. The machine can be depended on even in unfavourable weather. 

 It is simple in construction, and the peculiarity of it consists in the collection 

 of the positive and negative electric currents in two separate Leyden jars of 

 special form, which again are so connected together that the opposite electric 

 currents compensate each other. Thus the loss of electricity is reduced to a 

 minimum, and strong actions are obtained with the excited glass surface. 



4002. Calculating Disc, constructed on the system of Pro- 

 fessor Sonne. Specimen for demonstration, size 50 centimeters, 

 with rough division ; for instruction in schools. 



Landsberg and Wolpcrs^ Hanover, 



4002 a. Universal Lever, for lecturing purposes. 



C. Chzechovicz, Russia. 



Apparatus consisting of a set of levers and parallelograms, intended to 

 illustrate the principle of elementary statics, viz. : 

 The combination of forces applied to a body. 

 Combination of parallel forces. 



