"351 



Lecture Tables. 



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50. .'>.") 1. Lecture Table, in the Physics Lecture Room of the Ecole de mines du Hainaut. Mons. Price on 

 Belgium (Figure) .............................. 



The table is 6 m long. 1 m wide and 95 cm high. The top is of teak. 40 mm thick, being 

 composed of frame and pannellings. The body is of pitch-pine, the inner .side walls and bottoms of 

 red deal: it has 14 lock-up drawers. 1 long drawer for glass tubes, and 2 double door and 1 single 

 door cupboards with shelves. 



The table is fitted with the following: 1 gas lead. 1 water lead. 1 pipe line for aspirated air. 

 1 pipe line for forced air, 2 porcelain sinks with lead waste pipes, 1 draught pipe for gases and noxious 

 vapours. 1 heating device for electrical apparatus. 1 cavity for work involving the use of mercury. 

 1 lead pneumatic trough with direct water-inlet, overflow, valve waste, and 1 movable tall water , 

 discharge for filling vessels, etc. ; 4 pairs electric leads in conjunction with 4 30 amp. plug boxes at each 

 end: 1 marble switchboard with fuses, switch plug box with 30 amp. plug for the projector lantern. . 

 and 2 pairs slide rails for fixing of small dynamos and motors. 



The gas lead has 6 gas stopcocks with hose unions turned upwards, and 2 gas stopcocks 

 turned downwards, for the heating apparatus. The water line has 4 water taps with hose unions, 1 main 

 tap for filling the pneumatic trough, and 1 main tap for the tall water outlet in the trough. The 

 leads for aspirated and forced air each have 2 conical stopcocks with hose unions, the compressed air 

 lead having in addition a large rubber piece for blowing sirens, pipes, etc. At the left-hand side, where 

 the gas channel is placed, a slate slab. 75x60 cm, is let into the table top, upon which chemical 

 operations may be carried on. The heating apparatus and the mercury cavity are closed by wood 

 covers when not in use. and form a smooth surface with the rest of the table top. These two wood 

 slabs, and also the cover of the pneumatic trough (of slate) are lifted off by handles, which may be 

 inserted. The covers of the water waste and of the gas draught pipe are of iron, let into iron rings. 

 A terminal connected with the water lead serves to form a good earth. 



A second table. 2.5 m long, and 1 in wide, is carried out from the centre of the main table. 

 and at right angles to it. this continuation being made towards .the audience. Four pairs of electric 

 conductivy rails are let into the table top. being connected at the head to 4 plug boxes. The table 

 is provided with an arrangement for lowering the projection lantern. The projection lantern is 

 mounted on a wood board 1.35 m long and 52 cm wide with the auxiliary apparatus. The wood 

 board is hung upon 4 Gall's chains. The chains run over 4 sprocket wheels and are fitted at the free 

 ends with counterpoises. Each two siich wheels are firmly fixed to an iron shaft, these shafts being 

 set in motion by two worm wheels and worms. 



The entire device is placed inside the table, and is not visible from the outside. Only the 

 cranks of the driving shafts are inserted from outside. When the projection lantern is in use. i. e.. 

 when the wood board is raised up. the latter rests on two stout wood fillets, thus ensuring a farm 

 support for the lantern. When the lantern is lowered, the opening in the table top is covered by 

 two flaps moving in hinges, the table top then forms a plane, smooth surface. 



See also the Lecture Tables at the commencement of this List. 



Cl. 4640 



