716 REPORT OF NATIONAL MUSEUM, 1891. 



S2X. TiiK Dksigninmj ok JJuildings and Matkrials of Construction — Coutiuued. 



Estimates of Jiiuouut and tost of luaterial. 



Designs and models of special contrivances for safety, comfort and conven- 

 ience in the manipnlation of elevators, doors, windows, etc. 



(For Heating and Lighting Systems, see 65 ) 



(For Drainage and Sanitary Plnmbiug, see 650 and 873.) 



Working plans for the inason, carpenter and painter — designs and models of 

 bonds, arches, coping, vaulting, etc; plastering and construction of ])nr- 

 titions; painting and glazing. 



Plans of appliances for hoisting, handling and delivering. 



Building matei-ials to artisans — scaiifolding and ladders. Special scaffolding 

 for handling great weights. Portable cranes and power elevators. 



Illustxations of the strength of materials. 



Plans and sections of special architectural forms — metallic door beams and 

 girders. Hollow bricks and other architectural pottery for heating and 

 ventilation. Metallic cornice and conduits. Shingles and sheathing. 

 Glass roofs, floors, and accessories. Architectural hardware. 



Methods of combining materials. 



Protection of foundations, areas and walls against water. 



Working plans for paving and draining. 



(For Timber, see 176; for Building Stones, see 242-246; Masonry, see 248; 

 Brick, Plain and Ornamental, see Division 44; Iron and Metals, see 276.) 



(Cements and Mortars, see No. 281; Artiiicial Stone, see Class 282.) 



829. Instruments of Precision f'or the Engineer and Architect. 



Instruments of the draftsman. 



Field instruments for measuring angles and leveling — compasses, theodolites, 



transits, rods and flags, levels, leveling by barometer. 

 Instruments for measuring lengths — rules, rods, chains, and tapes. Methods 



of adjusting instruments for temperature. 

 Instruments designed for rapid work for calculating cross-sections, etc. 

 Plumb lines for great depths, and appliances. 

 Testing machines and other instruments, not elsewhere classed. 

 829rt. Engineering Societies and Associations. 



83. Property, Trade, Commerce and Intercommunication. 



830. History of Commerce and Intercommunication. 



Early routes of traffic and commerce. Commercial centers in past ages, 



shown by maps, etc. 

 Statistics and literature. 



831. Methods and Media of Exchange. Stores and Shops. 



Money — coinage and its equivalents. A collection to show the actual media 

 of exchange in America in each period of a (juarter of a century from the 

 first settlement to the time of the confederation, and in each Presidential 

 term since. 



Similar collections of money for other countries and periods (not to be con- 

 founded with a numismatic collection which includes coins only) with 

 bank notes and other paper circulating mediums. 



Special collections of tokens, "shin-plasters," "wild-cat money," etc., illus- 

 trating the financial history of the country. Confederate bills. Conti- 

 nental bills. Postage-stamp money. 



Commercial paper — bills of exchange, securities. 



Methods of barter. 



Weights and measures as used in coumierce. Scales, balances, solid and 

 li(|uid measure as sold to merchants. 



