240 FA. Gooch — Forms of Laboratory Apparatus. 



readily removable and replaceable when it be- 

 comes necessary to pass the point of support of 

 the burette. The refractive action of the 

 meniscus upon the dark line upon the white 

 background acts just as in the enamelled 

 burettes which have recently come into use, and 

 serves to define exactly the level of the liquid. 

 Errors of parallax in observing are easily avoided 

 by placing the eye in such position before read- 

 ing that the front segment of the circle nearly 

 completed by the edge of the upper ring falls 

 into coincidence in perspective with the back 

 segment as shown in the figure. 



Apparatus support. — The simple device illus- 

 trated in fig. 2 and fig. 3 has been in use for several 

 years in this laboratory wherever a rod support is 

 desirable and "has almost entirely replaced the 

 movable stand which students usually find un- 

 wieldy and difficult to dispose of in limited 

 space. The brass fitting into which is cut a 

 strong screw thread, as shown in fig. 2, is set 

 directly in the face of the work table with its 

 upper surface flush with that of the table, and 

 is held in place firmly by screws if the table-top is of wood, or 

 by bolts and nuts if the table top is of soapstone or other 

 material which does not afford holding ground for ordinary 

 Iron rods of sizes and lengths suited to holding all 

 sorts of apparatus, from the lighter 

 forms used in elementary laboratory 

 instruction to the heavier lecture appa- 

 ratus, are cut with screws matching the 

 thread of the brass fitting and may be set 

 firmly in place as shown in the figures. 

 The rods are of course interchange- 

 able as occasion may require. When 

 stripped of apparatus the rod takes up very little 

 table space, but if a clear table is desh-ed, it is 

 easy to remove the rod by means of tongs kept 

 at hand for the purpose in the laboratory tool- 

 box. This device is neat, inexpensive, and 

 easily made by any worker in brass and iron. 

 Steam evaporator. — A convenient, simple and inexpensive 

 form of individual steam-bowl is easily constructed in the 

 form shown in fig. 4 wherever steam connections are available. 

 An ordinary glass funnel of suitable size is hung in an iron 

 ring, for holding which the rod support previously described 

 serves admirably. The stem of the funnel is cut off short and 

 a T-tube is attached as shown, set in a short piece of rubber tub- 



screws. 



