MAWSON & SWAN, 



VACUUM TUBES. 



J- d. 



Set of 4 different Tubes, in 



cardboard box 060 



Set of 6 do., 2 varieties . . o 10 o 



Do. 6 do., larger .. .. o 18 6 



Do. 5 do., double envelope o 18 6 



Do. 5 do., larger . . . . 120 



Gassiot's Cascade 



7/6, 1 1/-, i6/- and i 4 o 

 Flat Spiral in Globe, with or 

 without liquid 



8/-, 9/-> I3/-I 20 /- and * 4 o 

 Marguerite Spiral 



8/-, 9/-, I3/-, 2o"/- and 140 

 Conic Spiral . . io/-, i6/- and 140 

 Ganot's Tube 



io/-, i5/-, 2O/- and 140 

 Tube with 2 Concentric 

 Globes, with different gases 



8/- and 0160 

 U Tube, with or without 



liquid .. 9/-, ii /-, 15 /- and 140 

 Bent Tube, with 6 fluorescent 



liquids 2 o o 



Do. do. do. . . i io o 



Egg-shaped Tube, with cross 



8/-, i6/- and 140 

 Long Tube, with uranium 



bulbs . . io/-, I4-/, 2O/- and 140 

 Spiral Tube, 8/6, 1 6/-,24/- and i io o 



Flower with 4 petals 



1 1/-, i6/- and 

 Flower with 2 petals 



1 1/-, i6/- and 

 Coquille Dentelee 



io/-, I5/- and 

 Tete de Diable . . 10/6 and 



Do. Chinaman 

 Holtz Tube, to show the direc- 

 tion of currents . . 2O/- and 

 De la Rive's Apparatus, to 

 show the rotation of cur- 

 rents 24/- and 



Spectrum Analysis Tubes, 

 Hydrogen, Oxygen, Nitro- 

 gen, Iodine, Cyanogen, Am- 

 monium, Carbonic Acid, 

 and Protoxide of Nitrogen 

 each 



The above in box complete 

 Luminous Diadem 



2O/-, 4O/- and 

 Do. Aquarium, 2O/- and 

 Do. Miner's Lanip 

 Medical Tube to illuminate 



the Throat 



Luminous Inscription on 

 black board, each letter ac- 

 cording to size, 2/-, 4/- and 







o 14 

 o 14 



2 O 



d. 



i 4 o 



i io 

 o 14 



i 16 o 



o 16 o 



080 



MAGNETO-ELECTRIC MACHINES. 



In these instruments the electricity is produced by the rotation of a 

 coil of insulated wires in front of or between the poles of a permanent 

 magnet, therefore no Battery is required ; the strength of the current is 

 adjusted by the position of the armature or keep. 



Magneto-Electric Machine, in mahogany case, and drawer containing 

 set of directions, 2 55. 



Magneto-Electric Machine, on marble slab, 2y/- 



Do. dp. first-class make, with handles, complete, 



24/-, 28/6, and 35/- This is the kind in very general use. 



3 and 15, Mosley-street, Newcastle-on-Tyne. 



