MISCELLANEOUS. 881 



4458. Two Sectional Models of Steam-engines. 



4459. Model of a Screw Steamer. 



4460. Lever Pyrometer. 



IV. J. Rohrbeck, J. F. Luhme $ Co., Berlin (Dr. H. Rohr- 

 beck). 



Chemistry. 



4461. Plattner's Assay-balance, for blow-pipe purposes, 

 in mahogany case, with 1 gr. weight, indicating -^ milligr., with 

 weights. 



4462. Balance, on stand, according to Wackenroder, to 

 carry 20 gr., and indicating 1 mgr., &c. 



4463. Technical Balance, on stand, to carry 500 gr., and 

 indicating 5 mgr. 



4464. Mohr's Tare-balance, in mahogany scale case, with 

 brass column, bow-scales, and ebonite plates, to carry 1 kilo- 

 gramme, and indicating 1 centigr. 



4465. Scales, for weighing substances affecting metals, to 

 carry 250 gr., and indicating 5 mgr. 



4466. Complete Mohr's Balance, for determining the 

 specific weight of liquid and solid bodies. 



4467. Mohr's Balance, with one arm. 



4468. a. Exsiccator, according to Schrotter, consisting of 

 tubulated glass jar on a frosted glass plate, framed in wood, with 

 crucible stand, and chloride of calcium tube. 



4469. b. Exsiccator, according to Fresenius, consisting of 

 glass cylinder, &c. 



4470. c. Exsiccator, according to Fresenius, with frosted 

 glass plate. 



4471. d. Exsiccator, according to Luhme, with porcelain 

 vessel for sulphuric acid, and etagere. 



4472. a. Drying Closet, according to Fresenius, of copper, 

 with two tubes and thermometer. 



4473. b. Drying Closet, according to Fresenius, of copper, 

 with grate, wire net, thermometer, and chloride of calcium tube, 

 for drying pulverised substances. 



4474. c. Drying Closet, according to Rammelsberg, with 

 two tubes and thermometer. 



4475. d. Drying Closet, according to Rose, with double 

 sides, two tubes, and thermometer. 



39508. 3 K 



