24 REPORT OF NATIONAL MUSEUM, 1893. 



The breaking of the view of a specimen or an exhibit by a horizontal 

 bar is also avoided, and when horizontal sash-bars are necessary (as 

 in a cheap case Avhere small panes of ^^lass are used) the situation is 

 relieved as much as possible by plai-ing a shelf behind this horizontal 

 bar, so that it is in eft'ect a part of the shelf. 



The form of case with which we are at present best satisfied is shown 

 in the illustrations of some of the groups of Indians. (Pis. 51 and 5l\) 

 Where smaller objects are shown, a large proportion of the height of 

 the case is occupied by the base in which "unit drawers" are fitted. 



We have also introduced an inexpensive and practical adjustment 

 of the doors of the larger cases, by means of Avhicli these may be raised 

 instead of swinging upon hinges, thus doing away with the exceedingly 

 objectionable swinging doors, so undesirable in narrow aisles and so 

 inconvenient to curators. With the new system the cost of the mechan- 

 ical appliances for swinging the sash is almost compensated for by the 

 saving in hinges, wrench-locks, clamping-bars, and special contrivances 

 for dust-proofing. The general appearance of these cases is shown in 

 the accompanying plate. (PI. 4.) 



So perfect is this adjustment that a glass door weighing more than 

 one hundred pounds may be lifted with one finger. The complicated 

 arrangement of cranks and levers used in many old-fashioned cases is 

 entirely unnecessary. 



The advantages of iron and steel exhibition-cases have been urged 

 with so much enthusiasm of late that it seeiiis i) roper to say that the 

 question of the use of iron has been constantly under consideration 

 here since 1879. All the different forms of iron cases have been studied, 

 including the Dresden cases constructed by Prof. Meyer which were 

 inspected by the writer in 1880, and the wooden-sheathed iron cases 

 in the American Museum of Natural History in New York. This was 

 before the .system of wooden cases, which we now use, had been 

 adopted. When the new Museum building was finished, in 1881, the 

 use of iron cases was practically decided upon, and sample cases were 

 made, in general accordance with the Meyer plans. They were found, 

 however, to be much more expensive than wooden cases, heavier, and 

 less easy to adapt to si)ecial uses. They offered no material advantage, 

 except, possibly, a greater durability. The limitations of iron in the 

 matter of design are manifest, and the impossibility of securing the 

 polished surfaces of wood, which add so much to the attractiveness of 

 a museum case, was another reason against iron construction. 



Looking back fourteen years to the time when iron was rejected, no 

 reason appears for regretting the decision then made. 



The use of Mexican or Frontier mahogany which is well known as 

 softer and straighter grained than the West India variety so i)opular 

 lor furniture, has been continued, and no other is so thoroughly suit- 

 able, so far as color is concerned, though the oaks when used have, 

 in other respects, given great satisfaction. When black cases are 

 required, cherry wood is employed and an ebony finish added. 



