and Laboratory Methods. 



2459 



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a bad arrangement. The difficulty of cleaning the whole door properly seems 



to outweigh all advantages. 



The height of wall cases has been much debated, those of the New York 



museum having been censured on account of their considerable height. In that 

 case the objection does not seem to be well taken. 

 There should be some relation of congruity between 

 the height of a hall and the height of the wall case 

 in a museum. If the former is lowered the latter can 

 be also, but a very high ceiling with too low wall cases 

 and immense unused wall spaces is distinctly dis- 

 agreeable. If, however, the wall spaces are used, or 

 if large objects surmount the cases, reaching up into 

 the unoccupied and useless vacancies of the wall, then 

 the wall cases may be reduced in height. The height 

 of the ceilings in the American Museum of Natural 

 History, in the larger halls, is about 'I'l feet, and that 

 of the wall cases is from 9 to 10 feet, outside meas- 

 urement, or more than one-third the height of the ceil- 

 ing. This brings the interior top shelf of the cases 



Fig. 43.— Depth and dimen- above the line of vision of most men by about one and 



sions of side of typical wall ^ half feet, SO that tall and coarse or less significant 

 case. ° 



specimens are restricted to it. This seem no par- 

 ticular disadvantage and results in no educational loss. It is also possible 

 to lower such a top shelf and leave the upper wall of the case empty or 

 distinguish it by some planular exhibit, maps, drawings, explanations, etc., etc. 

 Effectiveness of linear relations counts for something in a hall, and while the 

 limit of 9 feet may be insisted on in high halls, a minimum of seven should be 

 made imperative. The high wall cases contain more room, and especially per- 

 mit an attractive spacing of the shelves. A deep moulding around the ceiling 

 of halls, and the use of two colors on the walls of a hall, will also mitigate the 

 altitude of high ceilings. 



An example of a satisfactory wall case with broad sashes and good depth, 

 chaste finish, and substantial construction is here given (Figs. 4'2 and 43) with 

 dimensions. These cases are 7 feet 

 10 inches from floor to ceiling, inside 

 measurement, have an inside depth of 

 twenty inches, with each sash space 

 provided at the back, opposite and 

 midway in the sash spaces, with up- 

 rights carrying ratchets for insertion 

 of brackets (see below). The door 

 closure is indicated in the section on 

 Fig. 44, the back rim of the door fall- 

 ing behind a, and fitting tightly against b ; the doors swing on pins, top and 

 bottom, perforating the metal plate which is given in Fig. 44 c. A plate is 

 bedded in the door, and in the case. 



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Fig. 44. — Plate hinge for door of typical wall case. 



