Laboratory Apparatus FOR CHEMICAL, INDUSTRIAL, BACTERIOLOGICAL/ BIOLOGICAL, BOARD OF HEALTH ANE):- .-;: SOIL TESTING LABORATORIES MADE IN AMERICA CATALOG C No. 218 A. H. McCONNELL, President Established H. C. ARMS, Vice-President Incorporated 1889 J. M. ROBERTS. Secretary 1900 MANUFACTURED AND SOLD BY CENTRAL SCIENTIFIC CO. it 460 East Ohio Street (Lake Shore Drive, Ohio and Ontario Streets) CHICAGO U. S. A. CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. The Central Corridor of Our Spacious and Well Lighted Offices. A Corner of Our Display Room. CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. Looking Down the Central Aisle of Our Instrument Shop. Our Heavy Duty Machinery Eoom. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Our Chemical Stock and Packing Room. One Corner of Our Glass Shop, which Includes in Addition to the Lamp Boom (shown here) a Graduating and Grinding Boom, an Acid Room, an Annealing Furnace, a Stock and Preparation Room and a Business Office. CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. A View of Our Shipping Boom. One Section of Stock Bins Showing How Goods are Stored When Taken Out of the Original Cases. Over 40,000 Square Feet of Floor Space are Occupied by Our Stock of Scientific Apparatus. One Section of Our Eeserve Stock. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. TO OUR CUSTOMERS In bringing out this war edition of our Chemical, Industrial and Bacteriological Catalog we wish to call the attention of those into whose hands it comes to certain features which we believe are worthy of careful attention. AMERICAN MACE APPARATUS. We have eliminated from this catalog all apparatus which was formerly imported and has not been duplicated up to this time in this country. This is the first and only truly American catalog of chemical laboratory supplies published which pretends to be at all complete. The only important item of foreign manufacture listed is Whatman English Filter Paper, a line which baa won the support of all chemists, and for which no American substitute has as yet been introduced. UP-TO-DATE APPARATUS. We have selected only up-to-date types of apparatus, leaving out any forms which appear from our experience to be classical relies. PROMPT DELIVERIES. We have Included only apparatus which we know is being manufactured at this time, and can be delivered within a reasonable length of time. We can not, of course, predict the effect which the de- mands of the war may have upon the discontinuance of any manufactured articles, nor the effect of the demands of Government laboratories upon the adequacy of the supply. We are endeavoring to keep a large stock and every square foot of available space in the 2^4 acres of our 6 story building is packed to the roof with reserve stock. GLASSWARE AND PORCELAIN. Our stocks of glassware and porcelain have beeu selected from the American market after 3M> years of careful observation, experiment and comparison of data from various sources. We believe them to be the best adapted to the needs of American laboratories. We propose to change brands only after we have been convinced that such a change best serves the needs of the chemical trade. PRICES. The prices in this catalog were current at the time of publication. Owing to the rapid changes in the cost of raw materials and of labor, we cannot guarantee prices to remain constant for any length of time. We shall be glad to fill orders at prices current at the time of their receipt. If necessary to have the exact cost of materials, we urge our customers to send in their lists for quotation. ORDERS AND LISTS FOR QUOTATION. 1. When possible, specify our catalog number, name of article and dimensions. Further specifica- tion is not necessary. We furnish conveniently ruled order sheets upon request. Note: Lists made from catalogs of other dealers will be transposed by us into our own numbers when possible, with our guarantee that the articles will equal in efficiency and finish those originally specified. 2. Specify date when shipment is desired, with route and method of shipment, i. e., parcel post, express or freight. BOXING. No Charge for Boxing and Cartage except on orders of $10.00 or less; then a nominal charge will be made if the boxing exceeds five per cent of the value of the shipment. Prices are F. O. B. Chicago, unless otherwise specified. TERMS. Terms are net, thirty days after delivery. Orders from parties unknown to us should be accom- panied by remittance or by satisfactory business references. Note: Unless otherwise directed, invoices and statements will be mailed to the person placing the order, upon whom we relv to O. K. the Bills Promptly and thus Expedite Payment REMITTANCES. Remittances should be in exchange at par in Chicago, as we are obliged to pay exchange upon all private checks, except from a few of the largest cities. SHIPMENTS. Unless otherwise ordered, shipments are made by us At Once, by such routes as will insure earliest delivery. Large shipments are made by freight and smaller shipments by express or parcel post, as seems expedient to us. CLAIMS FOR BREAKAGE. We employ only experienced packers and guarantee our goods to be in first class condition when delivered to the carrier. Our responsibility ceases at that point, and all claims for damage or breakage must be made upon the carrier responsible for their safe delivery. We shall be glad to aid in any way possible in the prosecution of such claims and the recovery of damages. ORIGINAL CASES. We especially recommend that our customers take advantage of quantity purchases. American manufacturers of glassware and porcelain have made it possible to secure these commodities in original case lots at wholesale prices. RETURNED GOODS. In order to avoid the delays incident to the identification of returned goods, we respectfully insist that no articles be sent in without first notifying us as to the reason for their return and the disposition to be made of them. Frequently adjustments can be made without the necessity of returning the goods. If after consideration it appears necessary that the goods be returned, we shall send suitable shipping tags which will insure prompt attention upon their receipt. NOTICE TO THE TRADE. Special notice is given to the trade that this catalog is copyrighted, and that unauthorized repro- duction of new cuts or illustrations therefrom constitutes actionable infringement of our rights. We shall use every legal means to protect our work and property. Copyrighted 1918 by Central Scientific Company. CENTRAL SCIENTIFIC COMPANY. CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. No. 120. ABDERHALDEN REAGENTS, see Blood Testing Apparatus. 102. ABSORBENT COTTON, best quality. Size of package, ounces 1 4 1 (i Each $0.10 .20 .35 .65 ABSORPTION APPARATUS for Chlorine, see No. 2828. 106. ABSORPTION TUBE, Babo's, filled with glass beads. Total length, 13 inches; diameter of body, 1 inch. Will take an 8 inch column of beads $3.25 108. ABSORPTION TUBE, Camp's. Length of body, 13 inches; diameter, 1\{6 inch 3.00 110. ABSORPTION TUBE, Emmerling's, filled with glass beads. Total length, 15% inches; diam- eter of body, 1 inch. Will take an 8 inch column of beads 3.90 112. ABSORPTION TUBE, Fisher's, for the absorption of carbon dioxide or water in elementary organic analysis in place of the usual U tubes. It has the following advantages: 30 cc capac- ity instead of 22 cc of the ordinary 11 cm U tubes; more easily and thoroughly cleaned; only one hollow stopper which shuts off both openings with one turn; will stand on the bal- ance pan; and needs no hangers when joined in the absorption train. When filled, the bottle weighs about 65 grams. (See Journal of Industrial and Engineering Chemistry, Vol. VIII, No. 4, for April 1916, page 368) 5.00 114. ABSORPTION TUBE, Fleming's, for carbon determinations in iron and steel by the combustion method. Very rapid and exact, retaining every trace of carbon dioxide and moisture. One charge of soda lime will absorb 100 combustions, or one charge of phosphorus pentoxide 300 combustions on a 1.5 gram sample of 0.75 per cent, carbon steel 6.00 116. ABSORPTION TUBE, Hinman's, used extensively for the determination of ammonia in illumin- ating gas 75 118. ABSORPTION TUBE, as used by the Illinois Steel Company for absorptions in barium hydrox- ide, consisting of 9 bulbs with bent stem, for use with a 500 cc Erlenmeyer flask. Total length of tube, 201/> inches. Without flask. (See Journal of Industrial and Engineering Chemistry, Vol. VI, No. 10, for October 1914, page 844) 1.25 120. ABSORPTION TUBE, Meyer's, for the absorption of carbon dioxide in barium hydroxide; as described in Standard Methods for Chemical Analysis of Plain Carbon Steel, adopted in 1914 by the American Society for Testing Materials. Consists of a series of 10 small bulbs hold- ing from 10 to 15 ce each, with large bulbs at the ends having a capacity equal to that of the small bulbs combined 2.60 122. ABSORPTION TUBE, Nesbitt'S, for the absorption of carbon dioxide in soda lime in the deter- mination of carbon in iron and steel, designed by C. E. Nesbitt, chief chemist of the Carnegie Steel Company, Edgar Thomson Works. A slight turn of the stopper closes inlet and outlet tubes, sealing the bulb for weighing. The bulb filled weighs about 135 grams. Very rapid, enabling combustions to be run in 6 minutes. As many as 100 combustions may be run on a 0.50 per cent, carbon steel with 1.5 gram samples without refilling 3.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 123. No. 128. No. 132. No. 134. 123. ABSORPTION TUBE, Nesbitt's Improved, same as No. 122, but with inlet tube extended inside bulb and bent downward to diffuse gas through entire bottle $4.00 124. ABSORPTION TUBE. Vanier's (patented), for the absorption of carbon dioxide in potassium hydroxide in determining carbon in steel by the combustion method. Designed by George P. Yanier, Chief Chemist of the Pennsylvania Steel Company. Consists of a potash bulb and drying tube combined, capable of absorbing 100 combustions without refilling 10.50 126. ABSORPTION TUBE, Wesson's, designed by L. G. Wesson, of the United States Bureau of Standards. The apparatus weighs 20 to 25 grams empty. Will hold 35 grams of soda lime and 7 grams of calcium chloride, and will absorb 10 grams carbon dioxide without renewal. A capillary tube between the bulbs is substituted for a stopcock, making the outfit very light. (See Journal of Industrial and Engineering Chemistrv, Vol. VI, No. 6, for June 1914, page 461) 4.00 For other ABSORPTION TUBES AND BULBS, see Calcium Chloride Tubes; Potash Bulbs. ACID BASINS OR DISHES, see Dishes. ACID JARS, see Jars. ACID MEASURES TOR MILB^ see Milk Testing Apparatus. 128. ACID PITCHERS, of stoneware, with handle. Capacity, quarts 124 Each 40 .50 1.25 130. ACID PROOF FINISH for chemical laboratory tables. While this preparation is not absolutely acid proof, it is a finish which has been successfully employed for years in many of the leading laboratories. Consists of two solutions with full directions for applying. The finished top will be black Per gallon (V2 gallon of each solution) 2.50 132. ACID PUMP, with force pump attached, for withdrawing acid from containers. Will fit any bottle or carboy having a neck from 1% to 2% inches diameter 8.00 134. ACID PUMP for drawing acids and ammonia from carboys. Clamps hold it firmly to neck of carboy. Can be operated by Air Pump No. 1C986, or Foot Blower No. 1374 6.4 inches. . 1.10 638. BALANCE, Spring, English and Metric, with flat back and broad pointer, for either perpendicular or horizontal reading. Reads to 64 oz. in 1 oz. divisions, and 2,000 §rams in 25 gram divisions, priug elongates 2*4 inches. 60 640. BALANCE, Spring, English and Metric. Capacity, IS oz. in 1/5 oz. divisions and 500 grams in 10 gram divisions. Has flat back and sharp pointer, and is provided with several divisions above the zero to compensate for the sharp pointer in horizontal readings. Spring elongates No. 630. No. 636. No. 638. to 4 inches.. 3.30 No. 640. No. 644. 642. BALANCE, Spring, English and Metric, with flat back. Beads to 30 Ibs. in % Ib. divisions, and 15 kilos in 100 gram divisions. Spring elongates 5^ inches 2.30 644. BALANCE, Spring, English and Metric, in iron case with sliding index recorder. Especially designed for experiments in tensile strength, the indicator remaining at the breaking strain, instead of going back to zero when the strain is released, as in the ease of the regular spring balances. Reads to 30 Ibs. in *4 Ib. divisions, and 15 kilos in 100 gram divisions. Spring elongates 5^ inches 8.00 646. BALANCE, Stoddard Labora- tory, designed by Prof. J. T. Stoddard, Department of Chemistry, Smith College, Northampton, Mass. Capacity 121 grams; sensibility, less than 1 eg. Especially suited for use in Elementary Chem- istry, sine* it is much more accurate and easy to handle than tfce Horn Pan Balance, and more durable than the cheap equal arm Chemical Balance. Five riders are furnished, which weigh 10 g., 1 g., 1 g., 0.1 g., and 0.01 g., respective- ly, when placed on the first notch on the beam. These values multiplied by the number of the notch give the weight re- quired. For example, the balance in the illustration is in equilibrium with a mass of 37.7 grams in the pan. When not in use the riders are kept in a covered receptacle permanently attached to the base of the balance 7-50 No. 646. 54 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 648. No. 652. No. 650. No. 654. C48. BALANCE, Trip Scale, Cenco Agate Bearing, Harvard design. In this trip scale we have done away with the rough cast and forged iron parts used for years in the Harvard Trip Scale, and employ parts of brass and steel neatly formed by elaborate tools and machinery. This makes possible a degree of perfection never before attained in assembling this style of balance. We have discontinued altogether the cheap imported balances of the Robervahl type, as we believe the superior accuracy and durability of the Cenco Trip far outweighs the slight difference in price. The BEARINGS consist of HARDENED STEEL PRISMS resting on SIX AGATE SHELVES of large dimensions. This construction adds very materially both to the initial sen- sibility of the scale and to its ability to retain its sensibility after long continued use. The graduated beam has a range of 10 grams in 1/10 gram divisions. The capacity of the scale is 2000 grams. Sensibility is guaranteed to be 1/10 gram. Actual tests show a much greater sensibility. A very convenient feature of our latest design is a hook placed directly below the knife edges of each scale pan, from which objects may easily be suspended for specific gravity work. A set screw is also provided by means of which the balance may be clamped to a 13 mm support rod, and so elevated above the table top $7.50 650. SUPPORT, for No. 648 Trip Scale. Consists of a table clamp of special design (No. F197), and a No. F133 Support Rod, 20 cm long. This forms a most convenient means of supporting No. 648 Trip Scale for specific gravity work, as the scale is provided with a set screw for clamping to a support rod, and with specially designed hooks for supporting specimens which are to be weighed under water 1.25 652. BALANCE, Dispensing and Solution Scale, with Agate Bearings as described under No. 648. This balance will be found ideal for laboratory and pharmaceutical work. The pans are of heavy nickeled brass, 15 cm in diameter. The graduated beam has a range of 10 grams in 1/10 gram divisions, and brass weights from 10 grams to 100 grams are supplied, conveniently fitted into a projecting holder. Capacity, 2,000 grams. Sensibility is guaranteed to be 1/10 gram; actual tests show a much greater sensibility 10.00 654. BALANCE, Grain Test. Consists of No. 648 Cenco Agate Bearing Trip Scale with the addition of a funnel scoop and counterpoise, accurately adjusted 10.00 656. FUNNEL SCOOP AND COUNTERPOISE, only, of No. 654 2.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 55 No. 653. No. 700. No. 702. No. 706. 658. BALANCE, Triple Beam, Cenco, for physical and chemical laboratories. The three beams are placed in the same horizontal plane, thus conforming to scientific principles involved, which is not true of other styles of Triple Beam Balances. Weighings are obtained by movement of the riders along the beams. These riders are easily handled and quickly placed in the notches, but cannot be removed from the beams. An adjustable support is .provided for a jar or other receptacle for experiments in specific gravity. Provided with stable base neatly japanned, and with sensitive spirit level and leveling screw. Balance neatly finished in nickel plate and japan. Capacity of middle beam, 100 grams by 10 gram divisions; back beam 10 grams by 1 gram divisions; front beam, 100 centigrams by 1 centigram divisions. Total capacity, 111 grams; sensibility, with or without full load, guaranteed to 1 centigram. Actual tests, how- ever, give a sensibility of from 4 to 8 milligrams. Diameter of pan, 9.5cm; width of bow, 10.5cm; height of bow, 22cm. Features easily recognized are: rapid weighing, constant sensi- bility, accuracy, freedom from loss of weights, no interference or breaking of weights. . . $17.50 660. WEIGHT, Extra, for use with No. 658, for weighing over 111 grams, but not to exceed grams. Weight is placed on the 100 gram notch of the middle beam. Sold only at the time with No. 658. 201 same 1.75 WEIGHTS, ANALYTICAL 700. WEIGHTS, Analytical, Gold Plated, Highest Accuracy, adjusted to meet the requirements of the United States Bureau of Standards, Class M. Useful for checking accuracy of other weights. Gram weights made of Tobin bronze, one piece heavily gold plated; fractions of gram of plat- inum with 3 — 10 mg riders. In polished mahogany velvet lined box with hinged covers. Fur- nished with United States Bureau of Standards Certificate. No. A B Size 1 mg to, grams 50 100 Per set., 59.50 64.00 702. WEIGHTS, Analytical, adjusted within the tolerance of the United States Bureau of Standards for analytical work. All gram pieces are of brass, heavily gold plated. The fractionals from 500 mg to 50 mg are of Bhotanium A and from 20 mg to 1 mg of aluminum with 3 — 10 mg riders. In polished mahogany velvet lined box, with hinged cover, and with forceps. Each weight fitted in separate compartment. No. A B C D E F Size 1 mg to, grams 20 50 100 200 500 1000 Per set 23.00 25.00 28.00 37.00 44.00 53.00 704. WEIGHTS, Analytical, same as No. 702, but furnished with United States Bureau of Standards Certificate. No. A B Size 1 mg to, grams 50 100 Per set 40.50 43.75 7"0. WEIGHTS, Analytical, same quality as No. 702, but carefully lacquered instead of gold plated. No. A B " C D E F Size 1 mg to, grams 20 50 100 200 500 1000 Per set 21.00 22.00 24.00 30.00 36.00 43.00 50 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 708. No. 716. No. 718. No. 720. No. 710. 708. WEIGHTS, Analytical, Precision, for use with Nos. 450 and 452 Chain Balances. Of lacquered brass, with fractional weights from 5!)0 mg to 50 mg of platinum. Adjusted to within the tolerance of Class 8 Bureau of Standards. In polished velvet lined mahogany box. Complete with forceps. No. ABC Size 50 mg to, grams 20 50 100 Per set $22.00 23.00 26.00 710. WEIGHTS, Analytical, Fractions of Grams, of same quality as supplied in above sets. In pol- ished wooden box with slip lid, with separate compartment for each weight. 1-2-5-10-20 mg pieces of aluminum; 50-100-200-500 mg pieces of Rhotauium A per set 19.00 7 '.2. WEIGHTS, Analytical, Fractions of Grams, same as No. 710, but priced singly. / Aluminum — , , — — Rhotanium A < Size, mg 1 2 5 10 20 50 100 200 500 1000 Each 60 .60 .60 .60 1.00 1.50 2.00 3.00 4.50 8.00 WEIGHTS, Analytical. These weights are the same quality as No. 706, except the fractionals are of 22-caret solid gold, thus reducing the price due to the excessive cost of Rhotanium fractionals. No. A B C D Size 1 mg to, grams 10 20 50 100 714. Per set 14.00 15.50 18.00 21.00 715. Per set with Bureau of Standards Certificate 38.50 41.00 716. WEIGHTS, Analytical, Fractions of Grams, of 22-carat gold, as supplied with No. 714, in polished wooden box with slip lid, with separate compartment for each weight. Weights below 50 milli- grams are of aluminum 9.00 717. WEIGHTS, Analytical, Fractiors of Grams, same as No. 716, but priced singly. • i Aluminum — — , , — Gold — > Size, mg 1 2 5 10 20 50 100 200 500 Each '. . . .45 .45 .45 .65 .65 .95 1.20 1.30 1.50 718. WEIGHTS, Analytical, designed for student use, accurately adjusted. Gram pieces of solid brass, polished and lacquered. No loose balancing material used as all adjustments are made on knob stem. Fractionals of aluminum, the box of natural mahogany with hinged lid, velvet lined, with separate compartment for each weight. A pair of brass forceps is supplied. No A B Size 1 mg to, grams 50 100 Per set 10.50 11.75 719. WEIGHTS, Analytical, same grade as above except in block without hinged lid. No A B Size, 1 mg to, grams 50 100 Per set 9.25 10.50 720. RIDERS, Analytical, of aluminum, very carefully adjusted. Size, mg 12 10 6 5 3 2 1.2 1 .6 .5 Each 35 .35 .35 .35 .55 .55 .55 .55 .55 .65 CEXTKAL, SCIENTIFIC CO., CHICAGO, TT. 8. A. 57 No. 722. No. 736. No. 734. 721. WEIGHTS, Assay or Button, of Platinum, from 1 gram to 1 milligram with two riders; guaran- teed accurate to 0.01 mg. Weights from 20 mg down are of aluminum. In hardwood box ?24-00 722. WEIGHTS, Assay Ton, of hard brass polished and lacquered, in mahogany box. These weights are accurately adjusted to a standard of 29.1666 grams equals one Assay Ton which therefore contains as many milligrams as there are troy ounces in an avoirdupois ton. Hence if one A. T. of ore assays one milligram, the ore runs one troy ounce to the ton. Xo. ABC Size 1/20 A. T. to, A. T 124 Per. set $6.50 8.00 9.00 724. WEIGHTS, Assay Ton, single weights. Size, assay ton 1/20 1/10 2/10 5/10 1 2 4 Each . . . ." 1.00 1.00 1.00 1.20 2.30 2.60 3.25 72G. WEIGHTS, Factor, of brass lacquered, for the rapid analysis of iron and steel. A. Carbon Factor 2.7273 grams Each 1.30 B. ii Carbon Factor 1.3636 grams Each 1.30 C. %, Silicon Factor 1.1755 grams Each 1.30 D. Phosphorus Factor 1.63 grams Each 1.30 E. 1/10 Silicon Factor 0.4702 grams (platinum) Each 7.00 730. WEIGHTS, Normal Sugar, of brass, lacquered, in box. Xo. A B Set of 2 3 Consisting of, grams 13.024 13.024 26.048 26.048 52.096 Per set 5.20 . 6.50 732. WEIGHTS, Normal Sugar, separate weights. Size, grams 13.024 26.043 52.096 Each 2.00 2.00 2.00 WEIGHTS of MEDIUM GRADE for LABORATORY and TECHNICAL WEIGHING 734. WEIGHTS, Medium Grade, Metric, gram pieces of solid brass, flat shape, heavily lacquered; frac- tionals of German silver; in polished hardwood box with hinged cover, with forceps; with sep- arate compartment for each weight; fractionals under glass cover. Xo A B C D E F Size 1 mg to, grams 20 50 100 200 500 1000 Per set 4.50 5.50 7.00 9.00 12.00 15.00 736. WEIGHTS, Medium Grade, Metric, same quality as No. 734, but in polished hardwood block in- stead of box, with brass forceps. No A B C D E F Size 1 mg to, grams 20 50 100 200 500 1000 Per set 3.00 3.75 4.50 550 9.00 13.00 58 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 742. No. 738. No. 740. No. 754. No. 758. 738. WEIGHTS, Metric, separate weights, same quality as No. 734 and 736, for replacements. Size, grams ............. 1 2 5 10 20 50 100 200 500 1000 Each ................... $0.22 .25 .28 .33 .40 .50 .65 1.25 2.00 3.90 740. WEIGHTS, Metric, of polished brass, flat shape, in hardwood block with hinged cover, suitable for ordinary laboratory work. Nos. A-C are provided with receptacle for the fractional weights which are of German silver. Without forceps. No ................... A B C D E F Size ................... lcg-20g lcg-50g Icg-lOOg lg-200g lg-500g Ig-lOOOg Per set ................ 2.25 2.75 3.35 4.50 7.00 10.00 742. WEIGHTS, Metric, of brass, same as No. 740, but in hardwood block. Without forceps. No .................... A B C D E F Size ................... leg-20g lcg-50g Icg-lOOg lg-200g lg-500g Ig-lOOOg Per set ................ $1.65 2.00 2.75 4.00 6.00 9.00 744. WEIGHTS, Metric, Brass, same as Nos. 740 and 742, separate for replacements in other sets. Size, grams ............. 1 2 5 10 20 50 100 200 500 1000 Each .................... 11 .14 .17 .20 .25 .40 .55 .95 1.80 3.35 746. WEIGHTS, Metric, .Fractional, of German silver and aluminum. Set 1 to 500 milligrams, with duplicates of 2, 20 and 200 milligram pieces, in covered hardwood box with sliding cover. Each weight in a separate compartment; with brass forceps ........................... per set 1.65 748. WEIGHTS, Metric, Fractional, of German silver and aluminum, put up in sets of 1 mg to 500 mg with duplicates of 2, 20 and 200 mg pieces; in pasteboard box ................. per set .50 750. WEIGHTS, Metric, Fractional, Single, same as No. 748, for replacements ............ Each .05 752. WEIGHTS, Avoirdupois, of nickel silver, from 1/128 to 1/64, 1/32, 1/16, %, and % oz 754. WEIGHTS, Avoirdupois, of brass, in hardwood block, carefully adjusted. No ................................................... . . . . A B C Size % oz. to, Ibs ......................................... 124 Per set ................................................... 5.00 6.50 9.45 756. WEIGHTS, Avoirdupois, same as No. 754, single for replacements. Size, ounces ____ % }4 % 1 2 4 8 Pounds 1 Each ........... 29 .37 .43 .51 .72 .86 1.00 1.45 ounce, consisting of one each 1/128, Per set 2.00 2.30 4 3.90 758. WEIGHTS, Decimal Pound, brass in block, from 0.5 to 0.001 Ib. with duplicates of the 0.1, 0.01, and triplicates of the 0.001 Ib. weights. Adds up to make 1 pound. Especially valuable in test- ing laboratories where results must be reported in English units ................. per set 11.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 59 37 No. 764. No. 770. No. 774. No. 766. No. 768. 760. WEIGHTS. Prescription, according to the United States Bureau of Standards and the New York Board of Pharmacy. In box with cover from 4 drams to 1/10 grain, consisting of the follow- ing individual weights: 4, 2, 1, % drams; 2, and % scruples; 10, 5, 2, 1, 5/10, 2/10, and 1/10 grains ............. ........................................ . ................ per set $6.00 762. WEIGHTS, Prescription, from 2 drams to coin shaped, the grain weights of nickel grain, the dram and scruple weights of brass, per set .80 764. WEIGHTS, Troy, brass, in hardwood block, adjusted to meet requirements of the Bureau of Standards, Tenth Annual Conference on Weights and Measures. Weights below yt ounce fur- nished in pennyweights and grains unless otherwise specified. Xo ..................................... A B C D Size % grains to, ounces ................. 1 2 5 10 Per set ................................ 1.65 2.60 3.60 5.85 766. WEIGHTS, Troy, of aluminum, square, from % grain to 10 grains, in pasteboard box. Shape is such that they may be picked up readily ....................................... per set .65 768. WEIGHTS, Troy, from % grain to 5 grains in pasteboard box. Bent from aluminum wire, in shapes convenient to handle ............... .................................... per set .75 WEIGHTS, ORDINARY GRADE, FOR COARSE WEIGHING 770. WEIGHTS, Avoirdupois, Iron, sealed, in nests. Xo Size 14 °z- to, Ibs Per set . A 1 2.30 B o 2.80 C 4 4.00 772. WEIGHTS. Avoirdupois. Iron, sealed, same quality as above, single for replacements. Size, ounces Each .. .35 1 .35 .35 4 .35 774. WEIGHTS, Avoirdupois, of iron with ring handle. Size, pounds Each . 8 .70 1 .55 Pounds 2 .85 1 70 1.00 4 1.70 4 1.40 776. WEIGHTS. Avoirdupois, safety valve. Size, pounds Each . 10 2.75 4 1.50 D 8 6.00 8 3.00 14 3.35 8 2.50 60 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 788. No. 792. No. 800-802. 778. WEIGHTS, Metric, Universal. These weights are of brass, finely finished, and are of a high degree of accuracy. They are provided with a hook at the top and an eye in the bottom, which is concave so that the weights can be stood upright on a platform balance. This is a dis- tinctly high grade set of weights and will be found of great value in physical laboratory experiments, as well as for general weighing. The set consists of nine weights ranging from 10 grams to 1 kilo, with duplicates of the 20 and 200 gram pieces. Complete in finely finished hard- wood block per set $6.00 780. WEIGHTS, separate, same as No. 778. Size, grams 10 20 50 100 200 500 1000 Each 25 .38 .50 .55 .65 .90 1.35 782. WEIGHTS, Metric, Universal. These weights are made of cast iron, neatly japanned, with the denomination in raised figures. Of same general nature as No. 778, but much less finely finished and accurate. The set comprises nine weigh! s ranging from 10 grams to 1 kilo, with duplicates of the 20 and 200 gram pieces. . .per s«t 3.35 784. BLOCK of hardwood, with holes to fit No. 782 weights. 60 786. WEIGHTS, separate, same as No. 782. Size, grams. 10 20 50 100 200 500 1000 2000 Each 13 .22 .25 .28 .35 .50 .90 1.45 788. WEIGHTS, Metric, Iron, in nests, carefully adjusted. Sets have duplicates of 20, 200 and 2000 grams. The 10 kilo weight supplied with handle. No A B C D No. 782. Size 5 grams to, kilos.. 1 2 5 10 Per set 2.25 3.35 7.25 12.25 790. WEIGHTS, Metric, Iron, Single, same as in No. 788, for replacements. Size grams 5 10 20 50 100 200 500 Kilos. Each . ' 13 .13 .18 .20 .22 .27 .45 792. WEIGHTS, Metric, Iron, Slotted, with holder. Set consists of one 500, five 100, one 50, two 20 and one 10 gram weights. These weights will fi No. 798 Weight Hanger listed below. . .per set 3.35 794. WEIGHTS, Metric, Iron, Single. More accurate and of better finish than No. 792, with slot to fit No. 796 Holder and No. 798 Hanger. Specially designed for use in Physics experiments with simple machines, forces, etc. Size, grams 10 20 50 100 Each " 22 .28 .33 .45 796. WEIGHT HOLDER, only, of No. 792. Useful for holding No. 794 weights 798. WEIGHT HANGER, for No. 794, weight 50 grams, capacity, 1500 grams 800. WEIGHTS, Metric, Iron, Slotted, for use with hanger No. 802. Size, kilos % 1 '2 Each 45 .65 1.10 802. WEIGHT HANGER, for use with No. 800 Weights, of iron with hook; weight, 1 kilo; capacity, 20 kilos . 75 No. 778. 1 .65 1.10 2.75 10 5.00 500 .65 .55 .50 5 2.75 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 61 No. 812. No. 822. No. 820. No. 826. BALANCE ACCESSORIES 810. BALANCE BRACKET or support, with drawer and key, for attachment to wall where it will be out of the way and less exposed to vibrations. Size of top surface, 60 x 35 cm, with raised edge $9.00 812. BALANCE COVER, of good quality rubber cloth. A very convenient protection to balances. Made to order to fit any balance. When ordering, please give extreme outside dimensions of balance case. Price, according to size, from 2.00 to 3.50 814. BALANCE DESICCATOR, triangular in shape to fit in corner of balance case. Of glass, 2 inches on a side, 1V& inches high 1.00 816. BALANCE LEVEL, circular brass frame, spirit filled; diameter 25 mm 4.00 818. BALANCE PANS of horn, 75 mm in diameter per pair .25 820. BALANCE READING GLASS or magnifier, to place before indicating scale to facilitate rapid readings ; on adjustable support 5.50 822. BALANCE RESTS, glass, to place under the leveling screws of balances each .10 824. BALANCE WATCH GLASSES, counterpoised, accurately adjusted for analytical work. Diameter, mm 50 62 75 Per pair 90 1.00 1.25 826. BALANCE WEIGHING SCOOPS, of aluminum, with lip and counterpoise. Accurately adjusted. Size B holds about 12 gms of wheat flour, size C about 50 gins. No. ABC Capacity about, cc 10 30 125 Each 2.25 2.50 4.00 62 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 828. No. 830. No. 838. NO. 836. No. 840. No. 842. 828. BALANCE WEIGHING SCOOP, of glass, flat bottom with spout. No. A B Length, ram 67 87 Each $1.00 1.20 830. BALANCE WEIGHING SCOOP, of German silver, with long spout and with counterpoise.. 4.25 832. BALANCE WEIGHING SCOOP, same as above with short spout 4.25 834. BALANCE WEIGHING SCOOP, of pure nickel, with spout and counterpoise, accurately adjusted. Diameter, 65 mm. Length over all, 95 mm 3.00 835. BALANCE WEIGHING SCOOP, Cope, for int.'oducing a weighed sample directly into a long neck flask. The scoop is made of aluminum and has a cylindrical extension and lock pin by which a long handle is attached. Complete with scoop and brass and wooden handle (See Technical Paper 160 of the United States Bureau of Mines) 2.00 836. BALANCE WEIGHING TUBE SUPPORT, nickel-plated, for horizontal or vertical use... 2.00 838. FORCEPS, for use with sets of weights; brass with curved points; ivory tipped, heavily lacquered 1.50 840. FORCEPS, of brass with curved tips 25 842. WEIGHT BLOCK, of polished wood, with sliding cover, empty, with separate compartments for holding fractional weights No. 712 and 748. Convenient for placing in balance case 50 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 63 B No. 854. No. 856. BALLOONS. Collodion, for hydrogen. Capacity, cc ". 250 500 1000 Each .". $0.45 .60 .85 S54. BALLOONS, Glass, very thin for weighing gases. Capacity, about 250 ec. Si yle A B C D Each 1.10 2.25 2.00 3.90 85G. BALLOON, Glass, Dumas Type, for determining the specific gravity of vapors. Of very thin blown glass. Capacity, about 200 cc 35 858. BALLOON, Rubber, pure gum, diameter about 5 cm .06 860. BALLOON, Rubber, pure gum, diameter about 15 cm 60 BAROMETERS No. 876. No. 880. 876. 880 BAROMETER, Aneroid. Sea Level Reading Type, with rearranged Weather Harks. This instru- ment is arranged in such a manner that it is suitable for use in any location from sea level to 3,500 feet elevation. The adjustment is very simple and no derangement of the working parts is necessary. Once adjusted for a given location by the observer, no further adjustment is re- quired. A list showing altitudes of Meteorological Stations in the United States is furnished with each barometer, and also a simple weather forecast card. To adjust the barometer for altitude for a given city, town or location, turn the brass plate set in the back of the case (this is easily done with the fingers) until the number of feet corres- ponding to the elevation of the city or town is opposite the arrow. The hand will then point to the proper weather mark and the reading will be the same as that of the U. 8. Weather Bureau, which is Sea Level Reading. Spun brass case, porcelain dial, 5 inches in diameter; adjustable stationary hand for marking the last position of the movable hand 12.00 BAROMETER, Aneroid. Same as No. 876, but with metal silvered dial and first quality com- pensated movement 18.00 BAROMETER, Aneroid, as adopted by the United States Xavy. A brass case barometer of extra quality, with specially finished movement compensated for temperature, and silvered open metal dial graduated to 0.02 inches. For altitudes up to 3,500 feet. Without altitude scale. The best barometer of this stvle on the market 18.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 881. 881. BAROMETER, Aneroid. Brass case, 5 inches in diameter; open porcelain dial; visible works. Graduated to 0.02 inches.... $11.00 882. BAROMETER, Aneroid, 4-inch card dial, open face, nickel-plated case. Graduations in both English and metric systems. For alti- tudes up to 3,000 feet. Without altitude scale 6.00 890A. BAROMETER, Mercurial, Cenco Improved, Fortin Principle. Has straight glass tube of heavy wall and uniform bore mounted in a hexagonal brass protecting case, and is provided with a screw ad- justment for changing the level of the mercury in the cistern. The scales are readable by means of a vernier to 1/10 mm and 1/200 inch. The lowest possible reading is 23 inches (63.5 cm), so that the barometer is not satisfactory for altitudes above 4,000 feet. (See No. 891A for a high altitude barometer.) Complete with thermometer having both a Centigrade and Fahrenheit scale . 25.00 891A. BAROMETER, Mercurial, Cenco. Same as No. 890A, but with a scale reading down to 20 inches. For use in altitudes up to 10,000 feet 27.50 894. BAROMETER, Standard Mercurial, United Statss Weather Bureau Type, Fortin Principle. This barometer is of the highest type of No. 890A. excellence, indorsed by the United States Weather Bureau and fully warranted by the manufacturer. The mercury tube is inclosed in a brass body with gun-metal finish, having at its upper end two vertical openings, in which the vernier works, the latter operated by a rack and pinion movement. The readings are taken through these openings, aided by light reflected from a white opaque glass reflector attached to the board behind. The scale is graduated on one side in inches and lOths, and on the other in centimeters and millimeters, the vernier enabling a reading to be taken, in each case respectively, of one- thousandth of an inch and one-tenth of a millimeter. The attached ther- mometer consists of a well seasoned tube with both Centigrade and Fahren- heit scales, with the figures etched on the stem. It is so mounted that it can easily be removed for testing, etc. Beads down to 25% inches and is therefore not satisfactory for altitudes above 3,500 feet. Complete with board back of finely finished hardwood, to which is attached a brass bracket to receive the ring in the top of the barometer, a ring with steadying screws to clamp about the cistern, and white opaque glass reflectors forming a translucent background for reading the instrument 65.00 No. 894. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 65 No. 908. 1 i " i ! _* 922. No. 1 1 926. No 10 . 928. No. 895. 896. 898. 899. 900. 908. 909. 917. 918. 920. 922. 924. 926. 928. 930. 932. 934. BAROMETER, Standard Mercurial, United States Weather Bureau Typ«. Same as No. 894, but without the board back $57.50 BACK only of No. 894 Standard Barometer 7.50 BAROMETER, Standard Mercurial, United States Weather Bureau Type. Same as No. 894, but with a scale reading down to 20 in. for use in altitudes up to 10,000 feet 68.00 BAROMETER, Standard Mercurial, United. States Weather Bureau Type. Same as Xo. 898, but without board back 60.00 BACK only of Xo. 898 Standard Barometer, described under No. 894 8.00 BAROMETER, Recording (Barograph). Made in America. The movement is concealed in the base of the instrument and is worked by a large vacuum pan. In mahogany case, glass top and sides, and storage space for charts. Special charts, with instructions for weather fore- casting are supplied. Complete with full directions for use, charts for a year, pen and ink. 55.00 BAROGRAPH CHARTS, for No. 908 Barograph. In boxes containing one year 's supply. Per box 2.50 BAROGRAPH CHARTS, Style No. 2, for old style imported barographs reading 28 to 31 inches. In boxes containing one year's supply Per box 2.25 BAROGRAPH CHARTS, Unfigured, but graduated for a 3 inch range. For old style imported barographs. In boxes containing one year's supply Per box 2.25 INK, purple, for Barographs and Thermographs Per bottle .50 BAROMETER TUBE, unfilled, large bore, thick wall, one end sealed. Length, 80 cm .37 BAROMETER TUBE, unfilled, same as No. 922, with glass mercury well and pipette for filling 55 BAROMETER TUBE, unfilled, same as No. 922, but graduated in millimeters 2.50 BAROMETER TUBE, Demonstration Form, unfilled, with funnel top and with stopcock at top and bottom for easy filling and emptying of the tube. Total length, 104 cm. Graduated from 100 to 780 mm in millimeter divisions 8.00 MERCURY WELL, japanned iron. Capacity about 50 cc 40 BAROMETER TUBE, Siphon Type, unfilled, with bulb on short arm. Length, 80 cm 75 BAROMETER TUBE, Siphon Type, Bunsen's, unfilled. Graduated at the top of each arm in millimeter divisions 4.00 66 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 940. No. 946. No. 948. No. 958. BATTERIES, PRIMARY 940. 941. 942. 943. 944. 8040A 946. BATTERY, Buuseu, for open circuit work. A powerful two-fluid cell of about 1.9 volts E. M. F. and 1.86 ohms internal resistance. An excellent cell for operating induction coils, motors, etc., and for electrolysis of water. Quart size, complete without chemicals $2.25 CARBON for No. 940. 948. 949. 950. 951. 958. 959. 960. 961. 8040C. .12 ZINC CYLINDER with binding post for No 940 1.50 CLAMP for No. 941 Carbon, with binding post for wire POROUS CUP, 2x4 inches, for No. 940 1 GLASS JAR, 4x5 inches, for No. 940 30 35 20 BATTERY, Burn-Boston Addwater. A battery containing an exact balance of active elements, zinc, carbon, and salt solution. In dry cells destruction of the elements goes on continuously, whether used or not. In the Burn- Boston this process is arrested while the current is not being used. The zinc shell, being insulated from the electrolyte, cannot be acted upon by it. Except for a pin hole vent the cell is tightly sealed. All sources of leakage are thus done away with. Distinctive Features. (1) Yields from three to twelve times the service of dry cells. (2) "Will never leak or burst. (3) Can be stored, fully charged, for any length of time and in any climate. (4) "Will yield all of its phenomenal electrical content whether the period of use is three months or three years. Size, 7V^x2li^6x2ii/i6 inches; voltage, 1.5 volts; amperage, 20 amperes 1.25 BATTERY, Carbon Cylinder, for open circuit work. Well adapted for all telephone and bell service. Initial output, 1.4 volts, 6 amperes. Cell complete with chemicals 70 CARBON for No. 948 40 ZINC ROD with binding screw for No. 948 08 GLASS JAR for No. 948 30 BATTERY, Daniell, gallon size. This has been the standard cell for many years for open or closed circuit work. The best for all laboratory work in electrical measurements. Next to the standard cells, it gives the most constant E M. F., about 1.08 volts, which remains the same dur- ing the life of the cell. Internal resistance from 2 to 5 ohms. With new form riveted copper pocket for holding copper sulphate crystals. Complete without chemicals 2.00 COPPER, New Form, with riveted copper pocket, for No. 958 80 ZINC, weight about two pounds, with binding screw attached, for No. 958 60 POROUS CUP, 3x7 inches, for No. 958 50 GLASS JAR, 6x8 inches, for No. 958 40 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. 67 : No. 964. No. 966A-B. No. 966D. No. 971 (with cells). 964. BATTERY, Dry, Columbia, Red Label No. 6. The best dry cell on the market. E. M. F. on open circuit, l.o ; maximum amperage, 4 to 6; E. M. F. after delivering % ampere for thirty minutes, 1.36 $0.40 BATTERY, Edison Primary, the latest development, embodying all the good features of and many improvements in the class of cells formerly known as the Edison Lalande and later as the Edison Bsco Battery. The elements are the same as in the earlier types but the efficiency and effec- tive capacity have been greatly increased by a better proportioning of active materials and by an improved method of suspension. These cells are the best type of wet cell for continuous service because of their very low internal resistance and ease of renewal of exhausted parts. The new type of cell is contained in glass jars made of the new heat resisting glass, which possesses also greater mechanical strength than the porcelain jars formerly supplied. In selecting cells for laboratory use, it is important to select a sufficient number to secure the necessary voltage and to select those of size and capacity great enough to deliver current at the proper rate, as the larger sizes have very low internal resistance and long life and consequently operate at lowest maintenance cost. Initial E. M. F., 0.95 volts, decreasing to about 0.65 on average load. Distinctive Features. (1) E. M. F. constant through life of cells. (2) Simplicity and ease of renewal. (3) Visible indication of approaching exhaustion. (4) Uniformity of units. . i (5) Long life and service. (6) Entire absence of local action. (7) Low maintenance cost. Xumber A B C D Type 202 252 402 502 Size over all, inches 3%x6xll 3%x6xl2 5%x6%xl2i4 5%x6%xl2% Average internal resistance, ohms 0.05 0.05 0.04 0.04 Capacity, ampere hours 200 250 400 500 966. COMPLETE CELL 4.05 4.25 5.70 6.15 967. COMPLETE RENEWAL ......' 2.25 2.45 3.15 3.60 968. GLASS JAR 1.40 1.50 2.40 2.40 969. PORCELAIN COVER .45 .45 .50 .50 970. TERMINAL NUTS AND WASHERS Per set .25 25 .25 .25 971. BATTERY TRAYS, of pressed steel heavily japanned, for use in assembling Edison primary bat- teries in units of various sizes. Provided with handles and with open sides for inspection of ele- ments. For use only with types 202 and 252 cells. Number ABC Type 2022 2023 2024 For cells, number 2 3 4 Size over all, inches e^xll^xS 6V»xliy>xl2 6y,xllV>xl5% Each 2.40 2.70 3.00 Number D E Type 2025 2026 For cells, number 5 6 Size over all, inches 6%xll%xl9% Each 3.30 3.60 68 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. MIO CLANC CEll No. 976. No. 980. No. 994. 972. 973. 960. 961. 8040C. 976. 977. 978. 8040C, 980. 981. 982. 983. 984. 985. 986. 987. 988.. 989. 990. 991. 994. 995. 950. 997. BATTERY, Fuller, improved form, for open or closed circuit work. E. M. F. about 2 volts; initial internal resistance about 0.25 ohms. Gallon size, complete without chemicals $2.00 CARBON AND COVER for No. 972 90 ZINC for No. 972 60 POROUS CUP for No. 972 '. 50 GLASS JAR, 6x8 inches, for No. 972 40 BATTERY, Gravity, Crowfoot Type, especially adapted for closed circuit work. Standard type for telegraph companies. E. M. F. about 1.1 volts; internal resistance from 1 to 5 ohms. Gal- lon size, complete without chemicals 1.20 COPPER for No. 976 17 CROWFOOT ZINC, with connector, for No. 976 70 GLASS JAR, 6x8 inches, for No. 976 40 BATTERY, Grenet, French Type, pint size. Most convenient form for use on lecture table, giv- ing very powerful current for a short time. The E. M. F. is 2 volts at the start. Small inter- nal resistance. Height of cell 8 inches. Complete without chemicals 2.00 15 25 .60 CARBON for No. 980 ZINC for No. 980 GLASS JAR for No. 980, complete with brass ring BATTERY, Grenet, French Type, one-quart size. 10 inches high. Complete without chemicals. 2.50 CARBON for No. 984 ZINC for No. 984 GLASS JAR for No. 984, complete with brass ring .20 .30 .90 BATTERY, Grenet, French Type, two-quart size. 12 inches high. Complete without chemicals. 3.35 CARBON for No. 988 35 ZINC for No. 988 , 40 GLASS JAR for No. 988, complete with brass ring 1.20 BATTERY, Le Clanche, for open circuit work. Initial output. 2 to 4 amperes at 1.45 volts. Com- 65 50 08 .17 plete with chemicals POROUS CUP, sealed, for No. 994, complete with chemicals ZINC ROD with binding screw for No. 994 GLASS JAR for No. 994. . CENTBAL SCIENTIFIC CO., CHI , 'AGO, TL S. A. 69 1000. 1001. 1002. 1003. 1004. 1005. 1006. 1008. 1010. 1011. 1012. 1013. 1014. 1016. 1017. 1018. 1019. 1020. 1021. 1023. 1024. No. 1008. No. 1016. No. 1020. BATTEEY, Cenco Plunge, Single Cell. A powerful, compact form of the bichromate battery, ex- pressly designed for laboratory and lecture table work. Elements can be quickly lifted out of the solution when not in use. Fiber top, with nickel-plated brass trimmings. Large zinc and carbon elements placed close together, reducing the internal resistance to a minimum. Initial E. M. F., about 2 volts; internal resistance when freshly charged, 0.15 ohms $2.75 BATTEEY, Cenco Plunge, Two Cells, in case with handles 6.50 BATTERY, Cenco Plunge, Four Cells, in case with handles 12.50 BATTEEY, Cenco Plunge, Six Cells, in case with handles 18.00 CAEBON PLATE for Cenco Plunge Battery, 4x3x^4 inches 25 ZINC PLATE for Cenco Plunge Battery, 4%x3x% inches 40 GLASS JAE for Cenco Plunge Battery, 4x4x8 inches 55 BATTEEY, Laboratory Plunge, Four Cells. Similar in construction to the Cenco Plunge Battery described above, the essential difference being in the elements, which are larger, and the ease, which has an easy lifting motion, with a deadfall catch not liable to slip. The elements are quickly removed from the solution. Each cell may be used singly, two or more in series, or in parallel. Any cell which is not required for use can be suspended by the hook from the axle. All parts are interchangeable. Unquestionably the best battery for the lecture table. Initial E. M. F., about 2 volts per coll; internal resistance when freshly charged, 0.15 ohms. Complete with case 14.00 BATTEEY, Laboratory Plunge, Six Cells. Same description as No. 1008. Complete in case 18.00 CAEBON PLATE for Laboratory Plunge Battery, 6^x2%x% inches 25 ZINC PLATE for Laboratory Plunge Battery, 9A 9B Diameter of air reservoir, inches 7% 9 11 Pressure obtainable, per inch, pounds 1 I1/., 1% Capacity, per hour, cubic feet 190 330 625 Each $7.50 9.90 14.60 1376. BLOWERS, Foot, Fletcher's, mounted on legs with rubber reservoir underneath, thus obviating the risk of injury. Specifications are same as given under No. 1374. No 10 10A 10B Each 8.70 11.40 17.40 1377. RUBBER DISKS for Nos. 1374 and 1376 Blowers. Adapted to Nos 9 & 10 9A & 10A 9B & 10B Diameter, inches 9% 11% 14*4 Each .40 .70 1.00 1378. NETS for Nos. 1374 and 1376 Blowers Each .45 1380. BLOWER, Hand Bellows, 7 inches in diameter 90 1382. BLOWER, Hand, of rubber, two bulbs, one covered with net for constant pressure 1.00 BLOWERS FOR POWER USE 1388. BLOWERS, Hot Air, electrically operated, for producing a constant stream of hot air; useful for quickly drying glassware such as large flasks, etc., also for promoting evaporations. Complete with double switch, one for blast at room temperatures, the ether for hot air, and with cord and plug for attaching to lamp socket. No A B C D A.C. D.C. For voltage 110 220 110 220 Each 1T.50 18.25 17.50 18.25 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. 89 No. 1398. No. 1400. 1398. BLOWER AND VACUUM PUMPS, Cenco Rotary, Electrically Driven, for producing a blast for the operation of blast lamps and for use with other laboratory devices requiring moderate air pressure or vacuum. The blowers are of small size, very compact, and with few parts. They are free from mechanical troubles and require practically no attention, except an occasional oiling. They are mounted on a cast iron base, direct connected to an electric motor, and are connected with a variable rheostat by means of which the speed and therefore the air pressure can be varied. A snap switch is mounted on the same base for starting and stopping the motor. Specifications : — Number of blast lamps operated simultane- ously, 2. Vacuum at maximum speed, 17 inches of mercury. Power consumption, 50 watts. Size of base, 8% x 8 inches. Height over all, 4]/4 inches. Range of speed, 600 to 2000 r. p. m. Pressure at maximum speed, 8 pounds per square inch. Cubic feet of air per minute, 0.75. Complete as described with blower, motor, rheostat and snap-switch mounted on base with 5 feet of cord and plug for attachment to any lamp socket. No A B C D A.C. B.C. For volts 110 220 110 220 Each $40.00 45.00 40.00 45.00 1399. BLOWER AND VACUUM PUMP only of No. 1398, with grooved pulley, but without base, motor or other accessories 12.00 1400. BLOWER AND VACUUM PUMPS, Cenco Rotary, Electrically Driven, similar to No. 1398, but of larger size and capacity, with constant speed motor. Specifications : — Size of base, 13 x 7% inches. Height over all, 7% inches. Speed, 1725 r. p. m. Pressure, 10 pounds per square inch. Cubic feet of air per minute, 1.4. Complete as described, with blower and % h. p. direct connected motor mounted on cast iron base, but without rheostat, switch, or connecting cord. No A B C X> A.C. D.C. For volts 110 220 110 220 Each 60.00 62.50 50.00 52.50 1401. BLOWER AND VACUUM PUMP, only of No. 1400, with grooved pulley, but without base or motor. . : 15.00 Number of blast lamps operated simultane- ously, 4. Vacuum, 20 inches of mercury. Power consumption, 175 watts. 90 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 1402. No. 1390. No. 1403. 1390. BLOWER, Automatic Electric Air Compressor and Exhaust Pump Combined. Provided with switch for automatic starting and stopping of the motor at variations of pressure. This switch operates only when the pump is used for pressure and the tank is connected only with the pressure outlet of the pump. Suction is obtained by attaching a tube to a hose nipple at the base of the cylinder. Complete with four gallon tank, pressure gage and motor compactly mounted on one base, 9%x32 in. Bore, in ........................ 1% Stroke, in ...................... 2% Free air per minute at 200 r. p. m., eu. ft ........................ 1% No For volts Size of motor, h. p Each . For pressure up to, Ibs •. . 40 Vacuum up to, in 26 Height over all, in 25% Weight, Ibs 92 ABC 110A.C. 110 D.C. 220 B.C. % % % $89.00 75.00 77.00 1396. TANK, of heavy galvanized iron, 12 gallons capacity, with 50 Ib. pressure gauge, petcock on upper end and two % in. iron pipe size bushings in the side for making connections. Dimen- sions over all, diameter 12 in.; height, 30 in 10.00 1402. BLOWER and VACUUM PUMP, Crowell Rotary (No. 0-D). This pump is used principally for vacuum work, giving from 29 to 30 in. of mercury, according to atmospheric conditions. It is fitted in an oil immersion box, which makes it practically leak-proof. Capacity about 2 cu. ft. of free air per minute. Inlet and outlet tapped for % in. pipe size. Requires about % h. p. to operate , 65.00 1403. BLOWER and VACUUM PUMP, Crowell Rotary. Same as No. 1402, but without the oil immer- sion box 52.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 91 No. 1406 (3-A & 4- A). No. 1408. 1406. BLOWER and VACUUM PUMPS, Crowell Type A. Adapted for all purposes requiring air under pressure of from 1 to 10 Ibs. to the square inch and any degree of vacuum not exceeding 24 in. The pressure is not dependent upon high speed or centrifugal force. There are no springs, gears, valves or unbalanced parts. Satisfactory for furnishing vacuum or pressure throughout the laboratory. Air receivers are usually not required, but are of advantage where a close regulation of the pressure is desirable. (See No. 1410.) No. 1-A 20 Cu. in. free air per revolution , Cu. ft. free air per min. at maximum speed 6.9 R. p. m. at maximum speed , 600 Approx. h. p. at 3 Ibs. pressure % Pulleys, in 4x1 Net weight, Ibs 24 Pipe size, inlet and outlet, in y2 Floor space, in 10x6^4 Each, without air receiver $26.00 2-A 45 13 500 % 4x1% 34 34.00 3-A 125 25.3 350 % 6x2% 90 1 22x14 53.00 4-A 280 5-A 460 40.5 53.2 250 200 1 1% 9x3 10x3 170 225 1% 2 28x17 34x20 60.00 100.00 1408. BLOWER and VACUUM PUMPS. Crowell Type D. For pressures up to 25 Ibs. per square inch and vacua from 29 to 30 in. of mercury. The system of lubrication is positive and auto- matically controlled by the air pressure. The heads are provided with water jackets for cool- ing. Construction throughout is heavier than Type A, adapting this type for heavier duty. (For Air Receivers see No. 1410.) No. 1-D 15 Cu. in. free air per revolution Cu. ft. free air per minute at maximum speed 4.3 R. p. m. at maximum speed 500 Approx. h. p. at 15 Ib. pressure or 29 in. vacuum % Pulleys, in 6x2 Approx. net weight, Ibs 70 Pipe size, inlet and outlet, in % Floor space, in 13x18 Each, without air receiver 75.00 2-D 40 9.2 400 1 8x2 115 % 14x22 88.00 3-D 100 17 300 12x4 250 1 19x34 118.00 4-D 280 40.5 250 4 14x4 425 1% 23x38 198.00 5-D 400 46 200 5 18x6 580 2 26x44 225.00 CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 1410. No. 1414. No. 1436. No. 1415. 1410. AIR RECEIVERS for Nos. 1406 and 1408, which can be set to blow off at any desired pressure by turning the adjusting nut. No For Blower No Height, inches Length, over all, inches Diameter, inches Capacity, gallons Net weight, Ibs Pipe size, inlet and outlet, inches. Each 1 2 3 4 5 1-AorD 2-A or D 3-A or D 4-A or D 5-A or D 12 12 20 24 24 18 18 26 30 32 8 8 10 10 12 2.6 2.6 6.8 8 11.7 15 15 28 32 S3 % % 1 1'i o $12.00 12.00 14.50 16.50 20.00 BLOWERS OPERATED BY WATER PRESSURE 1414. BLOWER, Muencke's, operated by water blast for either compressing or exhausting. With 30 pounds pressure it will run two ordinary sized blast lamps. Intended for connecting to water supply by rubber tubing. Complete with one Filter Pump No. 5476, zinc water chamber 4x8 inches, air outlet and stopcock for regulation 12.50 1415. BLOWER, Muencke's, same as No. 1414 but with vacuum gage to indicate amount of va- cuum . 20.00 BLOWPIPES 1430. BLOWPIPES, of brass, plain. Length, inches 8 10 12 Each. 20 .25 .30 1432. BLOWPIPES, of brass, with air chamber. Length, inches 8 10 12 Each 35 .45 .50 1433. BLOWPIPE MOUTHPIECE, of wood to fit blowpipes Nos. 1430 and 1432 Each .15 Per dozen 1.50 1436. BLOWPIPE, Berzelius Form, of brass, with hard rubber mouthpiece and platinum plate placed on end of jet. Can be taken apart 2.50 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. No. 1454. 1438. BLOWPIPE, Black's, japanned tin, removable brass tip. Length, 8% inches $0.20 1439. BLOWPIPE TIPS for No. 1438 Per dozen 1.00 1442. BLOWPIPE, Black's, new form, of brass, with removable tip that unscrews and wooden mouth- piece. Length, S1/^ inches • .70 1444. BLOWPIPE, Brazing, of brass with stopcocks for air and gas. Requires % inch gas supply. Size of air tube, $i6 inch; of gas tube, %6 inch; length over all, 14 inches 3.00 1446. BLOWPIPE, Fletcher's Hot Blast, of brass. Length, 10% inches 80 1448. BLOWPIPE, General Laboratory, of brass nickel-plated. The most convenient form of hand blowpipe or blast; of very light weight. Provides intensely hot flame, which is easily regu- lated in size and intensity from the finest needle flame to a large brush, by means of stop- cocks on the air and gas tubes. Especially valuable in sealing glass and in repairing large pieces not easily handled. Total length, 9 inches; weight, 4% ounces 5.00 1450. BLOWPIPE, Oxy-Hydrogen, all brass, on stand, with removable lime cylinder holder and two stop-cocks 8.00 1451. BLOWPIPE only of No. 1450 7.00 1454. BLOWPIPE, Planner's, of brass nickel-plated, with hard rubber mouthpiece, but without plati- num tip 1.70 1455. BLOWPIPE TIP, of Platinum, for No. 1454, seamless, with small uniform hole. Price depend- ent upon the market price of platinum. 1458. BLOWPIPE, Plattner's, brass, with hard rubber mouthpiece, fitted with side arm with stop-cock for attaching directly to gas supply, giving a very powerful blowpipe flame 3.00 BLOWPIPE APPARATUS BLOWPIPE TIPS for burners, see Nos. 2228 and 2230. BUNSEN BUENEB for blowpipe work, see general heading Burners. 1464. BUTTON BRUSH 60 1466. CARBON BLOCK, molded 65 1467. CARBON BLOCK HOLDER .36 1468. CARBON CYLINDER, molded, I%x3 inches .55 1470. CHARCOAL BORER, club shape 1.00 1472. CHARCOAL BORER, four cornered 70 1474. CHARCOAL HOLDER, with platinum wire and shield 3.00 1476. CHARCOAL SQUARES, with covers, for charcoal holder Each .40 1478. CHARCOAL STICKS, natural willow wood, 4xlx% inches Per dozen .50 1480. CLAY CAPSULES Per dozen .60 1482. CLAY CRUCIBLES Per dozen .70 CUPELS, Bone Ash, see No. 3628. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 1484. 1486. 1488. 1490. 1492 1494. 1496. 1498. 1500. 1502. 1504. 1506. 1508. 1510. 300. 1514. 1516. 1518. No. 1518. CUPEL HOLDEK, on wooden support, -with two molds and stamp of brass, nickel-plated. Height, about 3y2 inches $2.00 FORCEPS, Blowpipe, nickel-plated, with platinum tips. Length 5% inches. Price dependent upon market price of platinum. HAMMER, Plattner's, wooden handle 45 LAMP, of polished brass 1.25 MATRASSES, Glass, flask shape per dozen .72 MATRASS HOLDER 40 MINERALS for Blowpipe, 25 specimens, small size, in partitioned hardwood box 2.00 MINERALS for Blowpipe, 50 specimens, small size, each in tray, all enclosed in oak box. . 3.00 MINERALS for Blowpipe, 100 specimens, including all but the very rarest, each in tray, all en- closed in oak box 7.50 PLATINUM WIRE, with solid glass handle, for borax beads, etc 85 PLATINUM GOODS, see general heading Platinum Ware. REAGENTS, set of 14 one-ounce bottles filled with chemically pure blowpipe reagents, accord- ing to Fresenius 4.50 SCALE, Plattner's, of ivory, for silver beads 3.50 SCALE of Hardness, without diamond, 9 specimens 2.00 SILVER FOIL per ounce 2.00 STREAK PLATE, unglazed porcelain, 60x100x4 mm thick 40 TUBES, hard glass, 4x^4 inches, open at both ends per dozen .45 TUBES, hard glass, 4xJ/i inches, closed at one end ' per dozen .90 BLOWPIPE SET of Apparatus and Reagents, as designed by Prof. Butler of the Colorado School of Mines for use in the laboratory and field. The various pieces are compactly arranged in a case with compartments and receptacles, especially designed to avoid breakage. Outside dimen- sions, Il%x6%x2% inches. Complete with wet and dry fluxes, and with lamps for alcohol and oil 22.50 The set contains the following pieces: — 1520. 2 Sticks Charcoal 6 Open Tubes Large Test Tube Small Test Tube Ammonium Hydrate Cobalt Nitrate Hydrochloric Acid Sulphuric Acid Nitric Acid Tin POCKET HAND-BOOK OF BLOWPIPE ANALYSIS, by G. Montague Butler, M. E. ..... 1.00 BOATS, Combustion, see Combustion Boats. BOILERS, see Kettles. BOLTING CLOTH, see Sieves. Blowpipe Platinum Wires and Holder Combination Charcoal Borer, Magnet and Chisel Streak Plate Blue Litmus Red Litmus Anvil 3 Arsenic Tubes Microcosmic Salt Sodium Carbonate Bismuth Flux Borax Potassium Bisulphate Oil Lamp (brass) Alcohol Lamp (brass) Hammer Platinum Tipped Forceps CEXTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 95 Ko. 1536. No. 1558. No. 1556. No. 1538. BOTANICAL APPARATUS 1530. BOTANICAL ABSORPTION PAPER, 11x16 inches, as used in No. 1558 Plant Press. Heavy felt paper, very absorbent per 100 sheets $3.00 1532. BOTANICAL ABSORPTION PAPER, good quality blotting paper, size, 12x19 inches. per 100 sheets 1.50 1533. BOTANICAL ABSORPTION PAPER, same as No. 1532, but in sheets 19x24 inches. per 100 sheets 3.50 1536. BOTANICAL ADHESIVE TAPE, in rolls of 10 yards, % inch wide, gummed, ready for use. Made of white cloth, easily cut and readily applied, presenting a neat and inconspicuous appearance on the mounting sheet. In box with slot enabling it to be withdrawn in any amount per roll 3D 1538. BOTANICAL COLLECTING CASE (Vasculum), of metal, finely enameled in green, with door opening entire length. Size 15%x5x7% inches. Complete with leather shoulder strap and snaps 2.00 1540. BOTANICAL GENUS COVERS, of heavy manila paper, with surface specially prepared for writing upon. Size folded. 12x18 inches per 100 sheets 2.00 1548. BOTANICAL MOUNTING BOARD, good quality Bristol board, plain. Size, 11x17 inches. per 100 sheets 3.00 1549. BOTANICAL MOUNTING BOARD, same as No. 1548, but with printed form for plant descrip- tion. Size, 11x17 inches per 100 sheets 5.00 1552. BOTANICAL MOUNTING PAPER, of heavy unsized stock, strong and durable. Color does not deteriorate with age. Size, 11x17 inches per 100 sheets 1.50 1554. BOTANICAL MOUNTING PAPER, heavy weight paper of grayish color, unsized surface. Size 11x17 inches .' per 100 sheets 1.10 1556. BOTANICAL MOUNTS. Riker's, suitable for mounting any botanical specimen. The mount consists of two parts — a thin plate of photographic glass to which narrow flaps of linen morocco paper are neatly fastened, and a cardboard back to which is glued a thin layer of sterilized surgical cotton in which the specimens are imbedded. No A B C D Size, inches 5x6 6%x8% 8x12 12x16 Each 25 .30 .50 1.00 Per dozen 2.80 3.50 6.00 12.00 For other MOUNTS, see Specimen Mounts. 1358. BOTANICAL PLANT PRESS, simple, strong, portable, and satisfactory. Made of lattice work, it dries very rapidly, especially when used with No. 1530 Absorption Paper. Hung in sun- light or over a heater, specimens can be dried so rapidly as to preserve natural colors. From one to fifty or more specimens may be pressed at one time. Size, Il%xl6% inches. Com- plete with straps as illustrated 2.50 96 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 1560, Fig. 1. No. 1560, Fig. 2. No. F8841. No. F8847. 1560. 1562. 1564. BOTANIC AIi PLANT PRESS, Riker'S, consisting of a series of layers of tubular paper in serted between sheets of blotting paper and absorbent cotton so that all the moisture is freelj carried off by a current of hot air passing through the tubes. Fig. 1 represents a section showing the plant laid on the cotton. Fig. 2. The method of confining the heat from a lan- tern by a wrapping of paper dries the plants in a few hours and is adapted for camp or the tropics. If hung above a burner or placed in the sun splendid results are also obtained Directions for use accompany each press. No A B Size, inches 9x12 12x19 Each $2.00 3.25 BOTANICAL PRESSING PAPER, thin white absorbent paper, folded and cut, for use with No. 1530 Absorption Paper per 100 sheets .50 BOTANICAL SPECIES COVERS, of manila paper, size folded, Il%xl7% inches. Per 100 sheets 1.50 HERBARIUMS. Made in two sizes, 7%x9% inches, and 11x17 inches, uniform in design with the Atlas Not© Books. The portfolio form permits the specimens to be mounted scientifically according to the genus and species to which they belong. The plan also permits adding to or removing from the collection at any time. Hints on collecting, pressing and mounting speci- mens are found on inside cover pages. Each sheet contains a legend for classification, and an index is furnished. No Atlas No Size, inches . . No. of sheets. A 709 x9 40 B 1117 11x17 25 F8841. HERBARIUM, complete, as described above .30 .57 F8842. HERBARIUM COVERS only Per set .12 .20 F8843. MOUNTING SHEETS only Per 100 .42 1.40 F8847. PLANT DESCRIPTION PAPER, with spaces on one side for complete analysis of a plant; the 7%x9% inches, perforated for Nos. F8811 or F8842A Covers. In envelope I other side unruled. of 20 sheets '.*. Per envelope .07 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. 97 No. 1574. No. 1578. No. 1582. No. 1584. No. 1586. BOTTLES FOR GENERAL USE 1574. 1576. BOTTLES, narrow mouth, round, flint glass. Capacity, ounces % 1 2 To take cork stopper, No. .. 112 Number in original case 864 864 720 Per dozen 58 .62 .68 Per gross in original case. . $5.50 5.90 6.50 BOTTLES, narrow mouth, round, green glass. Capacity, gallons To take cork stopper, No Number in original ease Each . 4 3 432 .94 9.00 6 4 360 1.08 10.30 8 5 288 1.24 11.80 Per dozen in original case . 10 48 .30 2.80 12' 5 216 1.60 15.20 1 12 24 .48 4.40 1578. BOTTLES, wide mouth, round, flint glass. Capacity, ounces % 1 2 4 To take" cork stopper, No. 7 8 12 14 To take rubber stopper, No.. 3456 Number in original case 864 864 720 432 Per dozen . .60 .65 .70 1.00 6 14 7 360 1.15 8 18 8 288 1.30 12 18 8 216 1.68 16 6 144 1.78 17.00 32 7 72 2.70 25.80 2 15 12 1.60 18.00 16 20 9 144 1.84 32 26 11 72 2.80 Per gross in original case.. 5.70 6.10 6.70 9.50 10.70 12.20 16.00 17.80 26.70 1580. 1582. BOTTLES, wide mouth, round, green glass. Capacity, gallons Number in original case Each Per dozen in original case 36 .32 2.90 1 24 .50 4.50 2 12 1.75 16.70 1584. BOTTLES, extra wide mouth, round, flinl glass. Capacity, ounces 2 3 4 6 Diameter of bodv, inches • - • I'M* 1% 2%6 2% 2% Diameter of neck, inside, inches 1%8 1%6 1% 1% To take rubber stopper, No 5 6 6 9 9 Height over all, inches 2 2% 2%6 2% 3^6 Number in original case 864 720 576 432 360 Per dozen .94 1.08 1.23 1.45 1.67 Per gross in original case 9.00 10.30 12.20 14.00 1600 BOTTLES, tincture, flint glass, mushroom stepper. Capacity, ounces 1 2 4 8 16 Number in original case 864 720 432 288 144 Per dozen 1.75 1.94 2.30 2.80 3.86 Per gross in original case . . 16.80 18.70 22.20 26.90 37.00 Capacity, gallons % 1 Number in original case 48 36 Each 1.05 1.56 Per dozen in original case 10.00 15.00 1586. BOTTLES, tincture, flint glass, low form, with flat topped glass stopper. Capacity, ounces 1 2 4 8 16 Number in original case 864 720 432 288 144 Per dozen 2.00 2.20 2.60 3.20 4.35 Per gross in original case 18.90 21.00 24.90 30.50 42.00 Capacity, gallons % 1 Number in original case 48 36 Each 1.10 2.65 Per dozen in original case 10.50 25.40 64 9 48 5.00 48.40 5 . 19 6 3.00 31.20 64 is 48 5.15 49.40 5 6 3.10 30.00 8 2% 1% 9 3% 288 1.90 18.30 32 72 5.40 51.70 2 12 3.40 32.50 32 72 6.35 61.00 2 12 4.75 46.20 98 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. No. 1588. No. 1594. No. 1596. No. 1598. No. 1612. No. 1614. No. 1592. 1588. BOTTLES, tincture, flint glass, with reagent stopper. Capacity, ounces 1 2 4 8 16 Number in original case 864 720 432 288 144 Per dozen 1.75 1.94 2.30 2.80 3.86 Per gross in original case $16.80 18.70 22.20 26.90 37.00 Capacity, gallons % Number in original case 48 Each '. . . 85 Per dozen in original case 9.15 1590. BOTTLES, tincture, of amber glass, with glass stopper. Capacity, ounces 1 2 4 8 16 Number in original case 864 720 432 288 144 Per dozen 2.00 2.20 2.75 3.30 4.60 Per gross in original case 20.00 22.40 26.60 32.25 44.40 1592. BOTTLES, narrow mouth, green glass, with vertical stopper, for acids. pints gallons 32 72 5.40 51.70 1 36 2.15 20.80 32 72 6.45 62.00 8 288 2.85 27.70 Capacity 1 Number in original case 72 72 Each 35 .45 Per dozen in original case 3.60 4.90 1594. BOTTLES, salt mouth, flint glass, mushroom stopper. Capacity, ounces 1 2 4 Number in original case 864 720 432 Per dozen 1.80 1.98 2.40 Per gross in 'original case 17.20 18.90 22.70 Capacity, gallons Number in original case Each Per dozen in original case 1596. BOTTLES, salt mouth, flint glass, with flat glass stopper. Capacity, ounces 1 2 4 8 Number in original case 864 720 432 288 Per dozen 2.00 2.20 2.65 3.25 Per gross in original case 19.40 21.10 25.50 31.20 l/2 1 2 36 24 12 .75 1.15 2.50 5.40 11.40 23.80 48 .95 10.20 16 144 3.90 37.80 1 48 2.10 20.00 16 144 4.40 42.50 32 72 5.65 54.60 2 24 4.25 40.80 32 72 6.90 61.50 1598. BOTTLES, wide mouth, hollow ground glass stopper, enabling spoon or spatula to be kept in bottle. Complete with horn spoon. Capacity, ounces .......................................................... 2 4 Each ................................ ..................................... 50 .90 Per dozen ............................ .................................... 5.00 9.00 1610. BOTTLES, Aspirator, of heavy glass, with tubulature at bottom. No ..................................... A B C D E Capacity, gallons ............. ........... i/i 1 2 3 5 Each ................................... 2.o"o 3.25 5.00 8.00 12.00 1612. BOTTLES, Aspirator, of heavy glass, with glass stopper and glass stopcock ground in tubulature. Capacity, ounces Each Capacity, gallons Each y2 8.00 I 12.00 8 3.00 2 14.00 16 3.50 3 16.00 1614. BOTTLES, Aspirator, of heavy glass, with narrow outlet for connecting rubber tubing. Capacity, ounces ..................................... 4 8 16 Each ................................................. 60 .70 .90 Capacity, gallons ............................................ % 1 Each ....................... 1.65 1.75 32 4.00 5 19.00 32 1.10 2 3.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. 99 No. 1618. No. 1620. No. 1622. No. 1624. No. 1628. No. 1630. No. 1634 No. 1638. No. 1640. No. 1644. No. 1645. BOTTLES FOR SPECIAL USES 1616. BOTTLES, Aspirator, graduated, of heavy glass, with outlet for rubber tubing. Capacity, liters 1 2 4 Each $2.50 3.30 4.50 1618. BOTTLE, Balsam, with glass cap, and loosely fitting glass dropper. Capacity, 30 cc 32 3620. BOTTLE, Balsam, wide mouth, with glass rod and glass cap ground to fit against shoulder of bottle. Capacity, 30 cc 40 1622. BOTTLE, Dropping, with Barnes' pipette stopper, square shape. Capacity, 30 cc 10 1624. BOTTLES, Dropping, with ground in pipette, with rubber bulb. Capacity, ec 30 60 Each . " 38 .40 1628. BOTTLES, Dropping, with ground in thistle top pipette, with rubber cap to control delivery. Capacity, cc 30 60 Each . ". 40 .50 1630. BOTTLES, Dropping, Rauvier's, with ball top pipette ground in. Capacity, cc 30 60 Each ' 50 .55 1634. BOTTLES, Dropping, "TK", with grooved flat glass stopper. Capacity, ec 15 30 50 100 200 Each 20 .25 .30 .35 .45 1638. BOTTLES, Dropping, "TK", with grooved vertical stopper. Capacity, cc 30 50 100 Each 25 .30 .35 1640. BOTTLE, Dropping, Schuster's, with ground-in glass stopper. Capacity, 30 cc $0.60 1641. BOTTLE, Dropping, Schuster's, without stopper. Capacity, 30 cc 40 BOTTLES, Gas Generating, see Gas Generators. BOTTLES, Gas Washing, see Gas Washing Bottles. 1644. BOTTLES, Homeopathic Vials, long form. Capacity, drams 1 2 3 4 6 8 Dimensions, mm 63x11 75x12 90x14 90x17 105x19120x20 Per gross 1.75 2.10 2.80 4.20 5.60 7.00 1645. BOTTLES, Homeopathic Vials, short form. Capacity, drams 1 2 3 4 6 8 Dimensions, mm 42x14 58x16 64x19 68x20 80x22 83x24 Per gross 1.75 2.10 2.80 4.20 5.60 7.00 100 CENTRAL SCIENTIFIC CO., CHICAGO, II. 8. A. No. 1648. No. 1650. No. 1654. No. 1658. No. 1662. No. 1666. 1648. BOTTLE, Immersion Oil, unspillable, with -wooden stopper and wire dropper $0.60 1650. BOTTLE, Immersion Oil, with nickel-plated cap, which cannot gum, and device for regulating amount of oil on plunger 75 1654. BOTTLES, Insect, bent neck. Capacity, ounces % " Per dozen. 90 1.60 1656. BOTTLE, Insect, cyanide, for collecting and killing, 4 ounce, ready for use 25 1658. BOTTLE, Measuring, designed by C. V. Bockius, of the Underwriters' Laboratories, for rapidly measuring and delivering a certain quantity of reagent where an approximate measure- ment is sufficient. An air opening is provided at the top for controlling the flow. Gradu- ated to 25 cc in 5 cc divisions. Capacity of bottle, about 250 ce 6.00 1662. BOTTLES, Oil Sample, clear flint glass, with rounded shoulder and concave bottom. The 4 ounce size is cleaned and fitted with corks. Capacity, ounces 1 2 4 8 Each 07 .08 .12 .15 Per dozen 60 .80 1.15 1.50 1664. BOTTLES, Oil Sample, 4 ounce size, clear flint glass, with square shoulder and flat polished bottom. Cleaned and fitted with corks Each .20 Per dozen 2.00 1666. BOTTLES, Pressure, Lintner'S, for digestion under pressure, with glass cap and rubber gasket, mounted in brass frame. Capacity, cc 125 250 Each 3.00 4.00 CEXTBAL SCIENTIFIC CO., CU1CAGO, U. S. A. 101 No. 1674. No. 1690. BOTTLES FOR REAGENTS BOTTLES, Reagent, with raised letters with surfaces ground, listed below are manufactured. Only those bottles with labels PLEASE ORDER BY BOTTLE NUMBER. 1672. BOTTLES, Reagent, narrow mouth, 1 oz., height 3% inches .................... Per dozen $1.60 No. No. Cohaltous Nitrate .......... Co(NO,), (^325. Silver Nitrate (Amber) ..... AgNO, And, 341. Blank. 33fi. Gold Chloride 327. Platlnic Chloride . .......... PtCl 1674. BOTTLES, Reagent, narrow mouth, 4 oz., height, o~4 inches .................... Per dozen 2.40 No. 82. IB. 16. 31. 97 - 32. 426. 406. H 407. 408. 409. S6. 421. r..%. 29. 28. •—a. 410. 429. 1. 87. 414. 27. 410. 90. . Acetic Acid ............... HC,H,O. 100. Alcohol .................. CjH.OH" --86. Ammonium Carbonate ...... ( NH4),CO, '—¥15. Ammonium Chloride ....... XH,Cl" 411. Ammonium Hydroxide ...... NH,OH 88. Ammonium Molybdate ...... ( NH,),Mo,OM Ammonium Oxalate ........ < NH4t.C,O4 Ammonium Sulphide iAmberi.INH.KS~ Ammonium Sulpnocyanide. . . NH4CNS Ammonium Sulphydrate ..... NII,HS Barium Carbonate ..... • ..... BaCO, Barium Chloride ........... BaCL, Barium Hydroxide ......... Ba(OH), Barium Nitrate ............ Ba(NO,), Bromine for Hypobromite. Bromine Water. Calcium Chloride .......... CaCl, Calcium Hydroxide ......... CalOH), Calcium Sulphate .......... CaSO4 Carbon Disulphide .......... CS. Chloroform ................ CHC1, • Cochineal. Coralline. Cupric Sulphate ............ CuSO, Dimethyl Glyoiime ......... iCH,t,C.(NOU). Ether .................... (C.H5),6 " 60. Fehling's Solution. 59. Ferric Chloride ............ Fe,Cl, 416. Ferrous Sulphate ........... FeSo4 61. Hydrochloric Acid ......... HC1 427. Hydrochloric Acid. Con ..... HC1 Hydrochloric Acid, Dll ...... HCI 14. Hydrogen Peroxide ......... H,O. 417. Hydrogen Sulphide ( Amber). HlS~ 81. Indigo Solution. 4. Iodine Solution ............. I+KI 420. Lead Acetate .............. Pb(CjH,O,), 431. Litmus. 424. Magnesia Mixture 413. Magnesium S.rp'iate ....... MgSO, 38. Mercuric Chloride .......... HgCl, 422. 430. 425. "•" ~-423. 412. 94. 37. ""8. 11. 6. 12. 1". 9. 7. -"2"6. Mercuric Potassium Iodide. Mercurous Nitrate HgNo, Methyl Alcohol CH,OH Methyl Orange. Xessler's Solution. Nitric Acid HNO. Nitric Acid, Con. HNO, Nitric Acid, Dil HNO, Obermayer's Reagent. Oxalic Acid H.C,O. Phenol C.HJOH Phenolpbtbaleln. Picric Acid HC.H,(NO.),O Platlnic Chloride PtCl4 Potassium Carbonate K.CO, Potassium Chromate KlCrO4 Potassium Dichromate K"Cr.OT Potassium Ferricyanide K^Fe"(CN), Potassium Ferrocyanide . . . .K,Fe(CN)4) Potassium Hydroxide KOH Potassium Iodide KI Potassium Sulphate KJ5O, Potassium Sulphocyanlde . ..KCNS Silver Nitrate (Amber) AgNo, --" Silver Sulphate Ag.SO4 Sodium Acetate NaC.HjO, Sodium Carbonate Na,CO, Sodium Cobaltic Nitrite. Sodium Hydroxide NaOH Sodium Hydroxide for Hypo- bromite NaOH Sodium Phosphate NauHPO4 Sodium Thiosulphate NaIS,O, Stannous Chloride SnClI Sulphuric Acid H.SO", Sulphuric Acid, Con H;SO4 Sulphuric Acid, DU. H,SO4 Tinct. Guaiac. Turmeric. Blank. -***3 102 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 1676. BOTTLES, Reagent, 4 oz., set of 40 Reagent Bottles No. 1674, including the most common names used in the chemical laboratory: Nos. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36, 59, 61, and 3 blanks Per set $8.00 1678. BOTTLES, Reagent, 4 oz., set of 24 according to Fresenius, including Nos. 2, 3, 4, 5, 6, 7, 13, 14, ' "15). 16, 17, 18, 19, 20, 22, 23, 25, 26, 27, 29, 32, 36, 59 and 61 Per set 4.80 1680. ' BOTTLES, Eeagent, 4 oz., set of 12, consisting of Nos. 1, 2, 3, 4, 5, 15, 16, 20, 23, 26, 27 and 61. Tor oo* x% Per dozen $0.35 .40 .60 .90 1.25 1714. BOTTLES, Serum, or Vaccine, of amber glass. All capacities have same size neck, taking the same stopper. Capacity, cc 1 to 2 3 to 4 5 8 10 15 20 25 30 Per gross 2.25 2.80 3.50 4.25 5.60 7.00 8.40 9.80 11.20 1715. RUBBER STOPPERS, special form for Serum Bottles No. 1714 per gross 2.80 1718. BOTTLES, Shell Vials, round, straight wall. No. . 50 12 4 25 Per gross 2.00 Height, mm Diameter, mm Capacity, cc Per dozen 2 60 13 7 .27 2.50 3 70 15 11 .28 2.75 80 16 14 .33 3.00 75 25 34 .50 4.50 104 CENTRAL SCIENTIFIC CO., CHICAGO, IT. S. A. Nos. 1722-4. No. 1728. No. 1732. No. 1734. 1720. 1722. 1724. 1725. 1728. 1730. 1732. 1734. 1736. 1737. 1740. 1742. 1744. No. 1740. No. 1736. No. 1742. No. 1744, BOTTLES, Show, Inverted, for storing and exhibiting sample grains, chemicals, etc. 1 7% 2% .45 2 9 3% .60 4 11 4% 1.10 Capacity, pints % Height, inches 3% 4% 6 Diameter, inches 1 V-: 2 2% Each $0.25 .30 .35 BOTTLES, Specific Gravity, unadjusted, with perforated stopper. Capacity, approx., cc , 10 25 50 Each • .55 .65 .90 BOTTLES, Specific Gravity, accurately adjusted at 20° C., with perforated stopper. Capacity, ce 10 25 50 Each 1.25 1.45 1.80 BOTTLES, Specific Gravity, same as No. 1724, in tin case with counterpoise. Capacity, cc 10 25 50 Each 2.50 2.75 3.25 BOTTLES, Specific Gravity, Boot's, double walled, with vacuum, maintaining constant perature inside. With perforated stopper and ground cap. Capacity, cc 25 Each : 4.00 BOTTLES, Specific Gravity. Geissler's, with thermometer reading from 8° to 40°C. ii ground in central neck, and cap ground on side neck. Capacity, cc 25 50 Each 4.00 4.50 8 14 5% 2.00 100 1.60 100 2.25 100 4.00 tem- 50 5.00 100 5.50 BOTTLE, Specific Gravity, Hogarth's, specially recommended by the United States Bureau of Mines for coal and coke. Widely used for specific gravity of iron ores. Capacity, about 100 cc .......................................................................... 2.00 BOTTLE, Specific Gravity, Hubhard's, for asphalts, bitumens, and dense oils. With glass stop- per concave on under side, with opening 1.6 mm to permit escape of air. Height, 70 mm; diameter, 22 mm; capacity, about 24 cc .............................................. 2.00 BOTTLE, Specific Gravity, Le Chatelier's, for cement, special form reco'mmended by the United States Bureau of Standards for use in Government Specifications. (See Circular 33 of the United States Bureau of Standards.) Without certificate ........................... 6.00 BOTTLE, Specific Gravity, same as No. 1736, but standardized by the United States Bureau of Standards, with certificate ........................................................ 8.00 BOTTLE, Specific Gravity, Nicol's Tube, for liquids .................................. 70 BOTTLES, Specific Gravity, Regnault's, for liquids, with ground-in stopper. Capacity, cc ............................................................. 25 50 Each ................................................................... 1.50 1.70 BOTTLES, Specific Gravity, Regnault's, for solids, with ground-in neck and stopper. Capacity, cc .............................................................. 25 50 Each .................................................................... 2.00 2.50 CEXTHAL SCIENTIFIC CO., CHICAGO, TT. S. A. 105 No. 1748. No. 1750. No. 1752. No. 1754. No. 1756'. No. 1758. No. 1764. No. 1766. 1746. BOTTLE, Specific Gravity. Schumann's, for cement, with tube graduated to 50 ce in i/J0 cc divisions $2.75 1748. BOTTLE, Specific Gravity, Sprengel's, with ground on suction tube, and ground caps. Height over all, about 100 mm; diameter of tubes, 14 mm 1.50 1750. BOTTLE, Specific Gravity, Walker's, for very fluid liquids, as described in Bulletin 109 of the Bureau of Chemistry, United States Department of Agriculture, Capacity, about 20 cc. 2.00 1752. BOTTLE, Specific Gravity, Walker's, same as Xo. 1750, for very viscous liquids. Capacity, about 30 cc 2.50 1754. SPECIFIC GRAVITY BOTTLE, Weld's Precision. For the precise determination of the density of liquids and salt solutions as designed by Prof. Leroy D. Weld of Coe College. With ground-on cap and pointed stopper. Especially valuable for use with highly volatile liquids since the ground-on cap prevents evaporation. The pointed stopper prevents the formation of an overflow drop. With this bottle weighings can be made to an accuracy of 1/1000 of 1 per cent., or with twice the accuracy of those made with a flat stoppered bottle similarly capped. Capacity, about 25 cc 2.25 1756. BOTTLES, Specimen or Sample, of glass, round, with cork-lined aluminum screw-caps. Capacitv, ounces 1 2 4 8 16 Height.'inches 3% 3% 4% 4% 5% Diameter, inches 1% 1% 1% 2V> 3% Per dozen 75 .80 1.00 1.50 2.20 1758. BOTTLES, Specimen or Sample, of glass, square, with cork-lined aluminum screw-caps. Capacity, ounces 1 2 4 8 Height/inches 2% 31%, 4% 5%6 Side, inches 1% 1^ 113^6 2% Per dozen 75 .80* 1.00 1.50 For other SAMPLE BOTTLES and JARS, sec Jars, Sample; also Boxes, Sample. BOTTLES, Vacuum or Thermos, see Vacuum Bottles. BOTTLES, Sterilizer, see Xo. 12391. 1764. BOTTLES, Volatile Liquid, glass stoppered with ground-on glass cap. Capacity, ounces 2 4 8 16 Each . '. 75 .90 1.10 1.50 1766. BOTTLES, Washing, with heavy neck, fitted with rubber stopper and movable delivery tube. Capacity, ounces 8 12 16 24 32 64 Each..' 45 .50 .55 .60 .65 1.20 106 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 1768. 1770. 1772. 1774. 1776. 1778. No. 1776. No. 1782. No. 1784. No. 1786. No. 1788. No. 1778. 1780. 1782. 1784. 1786. 1788. BOTTLES, Washing, of Pyrex glass, with neck covered with wicker, for use with hot water. Capacity, ounces 16 32 Each $1.10 1.25 BOTTLES, Washing, all of glass, with ground connections, for ether. Capacity, ounces " 8 16 32 Each ' 1.35 1.65 2.20 BOTTLES, Washing, with ground connections and stop-cocks, for use with volatile liquids. Capacity, ounces 8 16 32 Each 4.80 5.00 5.50 BOTTLES, Washing, with Griffin's tube, for continuous flow. Capacity, ounces 8 16 32 Each 1.50 1.60 1.75 GRIFFIN'S TUBE only No. 1774 1.00 BOTTLES, Gas Washing, see Gas Washing Bottles. BOTTLES, Water Sample, 2 ounce capacity, with flat ground in stopper. Both stopper and bottle may be obtained numbered serially. In ordering, specify plain or numbered bottles, and if the latter, state the series of numbers desired. No A B Style plain numbered Each 20 .30 Per dozen 2.20 3.25 BOTTLES, Water, of stoneware, see Jars, Stoneware. BOTTLES, Wax or Ceresine, for hydrofluoric acid. Capacity, cc 30 125 250 500 Each 25 .50 .60 .80 BOTTLES, Weighing, conical form, very light, ground-in glass stoppers. Capacity, cc 15 30 60 Each 40 .50 .60 BOTTLES, Weighing, high form, flat bottom, without neck, "ground-in glass stoppers. No A B . C D E Height, mm 50 60 80 90 100 Diameter, mm 15 10 15 18 25 Each 30 .30 .30 .40 .50 BOTTLES, Weighing, low form, flat bottom, without neck, ground-in glass stoppers. No A B C D E F G Height, mm 40 50 50 50 60 60 80 Diameter, mm 25 25 30 40 30 50 40 Each 38 .44 .50 .55 .50 .75 .70 BOTTLES, Weighing, extra wide, flat bottom, without neck, ground-in glass stoppers. No A B C Height, mm 30 30 30 Diameter, mm 50 65 70 Each 1.10 1.60 2.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 107 * - L No. 1790. No. 1794, No. 1796. No. 1792. No. 1798. No. 1800. No. 1802. No. 1804. 1790. 1792. 1794. 1796. 1798. 1800. 1802. 1804. 1806. 1808. 1814. 1816. 1817. 1820. No. 1816. No. 1817. No. 1808. BOTTLE, Weighing Tube, set of two telescoping tubes, each 5 cm long inside, with ring han- dle on inside tube ................................................................ $0-25 BOTTLE. Weighing, Parr's, with cover ground outside, as used in coal analysis. Diameter 25 mm ; height, 20 mm ............................................................. 60 BOTTLE. Weighing Pipette, Grethen's Form, with glass stop-cock, for fuming acids; capacitv. 2 cc ............................................................................. 2.50 BOTTLE, Weighing Pipette, Lunge's, with two stop-cocks, for fuming acids, eiC. Capacity, about 15 cc ....................................................................... 4.50 BOTTLES, Woulff's, of heavy gla Each BULBS, Nitrogen or Kjeldahl, see Nitrogen Apparatus. BULBS, Rubber, see Rubber Bulbs. A 250 .25 B 500 .30 250 .55 C 1000 .35 500 .75 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Ill No. 1908. No. 1910. No. 1912. No. 1914. No. 1916. BURETTES No. 1918. No. 1920. No. 1922. 1908. BURETTES, for pinchcock, without fittings. Graduated in fa ec divisions. Capacity, cc 10 25 50 100 Each ..' $0.45 .60 .90 1.40 ATTACHMENT for No. 1908, see Burette Accessories. 1910. BURETTES, for pinchcock, with side tube for refilling, without fittings. Graduated in fa cc divisions. Capacitv, cc 10 25 50 100 Each .". 60 .75 1.05 1.60 ATTACHMENT for No. 1910. see Burette Accessories. 1912. BURETTES, with straight glass stopcock. Graduated in fa ce. Capacitv, cc 10 25 50 100 Each ..' 1.40 1.70 1.90 2.75 1914. BURETTES, with straight glass stop-cock and side tube for refilling. Graduated in fa cc divisions. Capacity, cc 10 25 50 100 Each 1.60 1.90 2.10 2.95 1916. BURETTES, with three-way stop-cock. Graduated in fa cc divisions. . ' Capacity, cc 25 50 100 Each 4.00 4.30 5.00 1918. BURETTES, with Fresenius stop-cock. Graduated in fa cc divisions. Capacitv, cc 25 50 100 Each .". 2.50 2.70 3.50 1920. BURETTES, with Fresenius stop-cock and side tube with glass stop-cock in same, for refilling, according to Gawalowski. Graduated in ^o cc divisions. Capacity, cc 25 50 100 Each 4.50 4.75 5.50 1922. BURETTES, with straight glass stop-cock to operate with left hand, and side tube with glass stop-cock in same, for refilling, according to Gawalowski. Graduated in fa cc divisions. Capacity, cc 25 50 100 Each 4.50 4.75 5.50 1924. BURETTES, Schellbach, for pinchcock, with blue line on white background to facilitate read- ing of meniscus; without fittings. Graduated in ^Q cc divisions. Capacity, cc 25 50 100 Each 2.20 2.50 3.80 1926. BURETTES, Schellbach, for pinchcock, with side tube for refilling, with blue line as in No. 1924, without fittings. Graduated in fa cc divisions. Capacity, cc 25 50 100 Each 2.40 2.70 4.20 1928. BURETTES, Schellbach, with straight glass stop-cock. Graduated in fa cc divisions. Capacity, cc 25 50 100 Each 3.00 3.50 5.00 1930. BURETTES, Schellbach, with three-way stop-cock. Graduated in fa cc divisions. Capacitv, cc 25 50 100 Each .". 5.00 5.60 6.76 112 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. I r No. 1932. No. 1934. A. B. No. 1946. No. 1950. No. 1951. No. 1952. 1932. BURETTES, Schellbach, Automatic, with zero point and overflow cup. With three-way stop- cock, for refilling from reservoir. Graduated in i{0 cc divisions. Capacity, cc 25 50 100 Each $6.00 7.00 8.00 1934. BURETTES, Automatic, Squibb 's, consisting of a Schellbach burette with Frosenius stop-cock mounted on reservoir. Complete with reservoir, clamp and suction tube, but without pres- sure bulb. Capacity of burette, 50 cc. Graduated in ifo cc divisions 9.00 1935. BURETTE only of No. 1934 5.40 1936. CLAMP only of No. 1934 75 PRESSURE" BULB for No. 1934, see No. 11530. 1946. BURETTES, Calibrating, Morse's, for flasks, burettes, and pipettes. No A B C Capacity of bulbs, ce 500 200 & 50 50, 3 & 2 Each 10.50 6.75 7.50 1947. STOP-COCK, three-way, for No. 1946 3.50 1948. BURETTE, Calibrating, Morse's, 1 cc, with three-way stop-cock, for small quantities... 6.00 1950. BURETTES, Dispensing, for pinchcock, without fittings. Capacity, cc 250 500 1000 Graduated in, cc 1 5 10 Each 4.00 4.50 5.50 1951. BURETTES, Dispensing, with straight glass stop-cock. Capacity, cc 250 500 1000 Graduated in, ce 1 5 10 Each 5.40 5.60 7.00 1952. BURETTE, Weighing, Ripper's, arranged for suspending from balance hook by aluminum wire. Graduated to 60 ec in 5 cc divisions 3.50 BURETTES, PRECISION 1958. BURETTES, Precision or Normal, for pinchcock, graduated to meet the requirements of the United States Bureau of Standards. With unofficial factory certificate. Without fittings. Capacity, cc 10 25 50 100 Graduated in, cc 1£0 i^0 i/j0 }£ Each 2.60 3.00 3.70 4.50 1960. BURETTES, Precision or Normal, with straight glass stop-cock with tip curved. Graduated to meet the requirements of the United States Bureau of Standards. With unofficial factory certificate. Capacity, cc 25 50 100 Graduated in, cc i^0 1£0 i/- Each 4.10 4.80 5.20 1962. BURETTES, Precision or Normal, with straight glass stop-cock with curved tip, tested by the United States Bureau of Standards. With control stamp and certificate of corrections. Capacity, cc 25 50 ] Ot i Graduated in, cc }. 2206 1.50 2211G. Pump for Xo. 2208 1.50 2211H. Cup Leathers for Xo. 2206 or Xo. 2208 Each .10 122 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 2211S. No. 2211U. No. 2215. No. 2211V. No. 2220. No. 2214. 2211J. Hexagon Nuts, any size for No. 2206 or No. 2208 - Each $0.05 2211K. Pump Caps for No. 2206 or No. 2208 Each .12 2211L. Plunger Knobs for No. 2206 or No. 2208 Each .12 2211M. Cork Washers for No. 2206 or No. 2208 Each .02 2211N. Springs for No. 2206 or No. 2208 Each .02 2211P. Cork Holder for No. 2206 or No. 2208 10 2211Q. Spring Plates for No. 2206 or No. 2208 Each .10 2211R. Plunger Bod for No. 2206 or No. 2208 15 22118. Plunger Rod, complete with knob, cap and slide for No. 2206 or No. 2208 50 2211T. Pump Collar for No. 2206 or No. 2208 20 2211U. Pump Bottom for No. 2206 or No. 2208 50 2211V. Pump Slide for No. 2206 or No. 2208 30 2214. BUHNERS, Gary's Gasoline Blast, producing intensely hot, clean flame. Recommended for use in heating Furnaces Nos. 6390 and 6398. No A B J)iameter, inches 1% 2 Each 13.25 15.75 2215. GASOLINE TANK OUTFIT for use with No. 2214, with heavy iron tank, tinned inside and out to prevent rusting and tested to a pressure of 100 pounds. Fitted with large brass hand pump on separate base. Complete with 12 feet of 14 -inch iron pipe, pressure gage, two swivel joints, necessary valves and fittings, but without burner. No A B Capacity of tank, gallons 2 7 Shipping weight, pounds 50 70 Each 31.50 42.00 Prices of extra parts for No. 2215 quoted on application. 2218. BURNER, Dangler's Gasoline Blast Lamp, flame easily adjustable. With tin reservoir, holding % gallon. Complete with rubber pressure bulb. Height of burner, 10% inches; height to top of support rod, 17 inches; diameter of reservoir, 7 inches 9-00 BULBS, Rubber, for No. 2218, see No. 11530. 2220. BURNER, Kerosene Stove, wickless, giving hot blue flame, without smoke or odor. Height, 8% inches; diameter of base, 9 inches. Without stand 7.50 2221 STAND for No. 2220, with top 8% inches in diameter 90 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 123 No. 2226. Ko. 2228. No. 2230. No. 2234. No. 2236. No. 2238. No. 2246. No. 2240. No. 2250. No. 2242. No. 2252. No. 2248. BURNER ACCESSORIES 2226. BURNER BLOWPIPE ATTACHMENT, to fit on a %6 inch burner tube. Takes the place of both blowpipe and blowpipe tip, leaving both hands free. Should be used with rubber tube and glass mouthpiece 50.90 2228. BURNER BLOW PIPE TIP, with rest, for blowpipe, fitting outside %6 inch burners 16 2230. BURNER BLOW PIPE TUBE, for yellow flame, fitting inside %6 inch burners 18 2232. BURNER CHIMNEY, of Russia iron, to protect flame from drafts, for use with No. 2246 Star Support. Diameter at bottom, 2 inches; at top, 1% inches; height, 2 inches 15 2234. BURNER CHIMNEYS, of Russia iron, with attached support. No A B For burner tube, diameter, inches tfa >£ Each .80 .85 2236. BURNER CROWN TOP, giving round flame, for heating dishes; diameter, 1 inch .50 2238. BURNER FORK for attaching burner to ring stand 30 2240. BURNER GAUZE TOP, giving large round flame; diameter, 1% inches .26 2242. BURNER GUARD, of vitrified earthenware for protecting a flame from drafts. Will also be found a rigid and convenient support, measuring 9 inches high, 8 inches diameter at base, 5 inches diameter at top. Provided with hole for rubber tubing and inlets for air to support combustion 50 2246. BURNER STAR for supporting No. 2232 Chimney .26 2248. BURNER SUPPORTS, of iron, with heavy screw for clamping on supports or tripods. No A B Diameter, inches 3% 5 Each 25 .60 2250. BURNER TRIPODS for holding dishes, measuring 2% inches between supporting points. No A B For burner tube, diameter, inches ^6 % Each 16 .18 BURNER TUBING, see Rubber Tubing. 2°5° BURNER WING TOPS for use in bending glass tubing. No : . A B For burner tube, diameter, inches %6 % Each . 09 .18 124 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. No. 2312. No. 2308. No. 2310. No. 2314. i^ No. 2300. 2302. 2304. 2306. 2308. 2310. 2312. 2314. 2316. 2318. 2320. 2300. No. 2302. No. 2316. No. 2318. CALCIUM CHLORIDE TUBES No. 2320. CALCIUM CHLORIDE JARS, Drying Towers, on foot, with tubulature near bottom. Height, inches 8 10 12 Each $1.80 2.50 3.20 CALCIUM CHLORIDE JARS, similar to No. 2300, but with perforated ground glass stopper and side tube near top. Height, inches Each CALCIUM CHLORIDE TUBES, one bulb, straight delivery tube. Length to bottom of bulb, inches 4 6 Diameter of tube, inches % 94 Each 11 .13 CALCIUM CHLORIDE TUBES, two bulbs, straight delivery tube. Length to bottom of first bulb, inches 4 6 Diameter of tube, inches % % Each 13 .15 CALCIUM CHLORIDE TUBES, with small inner tube to collect moisture in first bulb. Length to bottom of first bulb, inches 4 Diameter of tube, inches % Each 25 CALCIUM CHLORIDE TUBES, U shape, plain. Length, inches 4 Diameter of tube, inches % Each 12 CALCIUM CHLORIDE TUBES, U shape, with side tubes. Length, inches Diameter of tube, inches Each CALCIUM CHLORIDE TUBES, U shape, with side tubes and bulb on one. Length, inches 4 Diameter of tube, inches % Each ... 25 CALCIUM CHLORIDE TUBES, Marchand's, with cork and connecting tube. Length, inches , Diameter of tube, inches , Each CALCIUM CHLORIDE TUBES, Peligot's, U shaped with three bulbs. Length, inches 4 Diameter of tube, inches , % Each 30 CALCIUM CHLORIDE TUBES, Schwartz, with side tubes and perforated ground in glass stoppers. No A B Length, inches ' 4 6 Diameter of tube, inches %. % Each 1.40 1.75 CALIBRATING BXJRETTES, see Burettes. CALIBRATING PIPETTES, see Pipettes. 6 % .20 4 % 20 10 4.50 8 .16 8 .18 Ib. 8 .36 8 .25 0 % .25 6 % .35 4 .30 6 % .40 12 4.80 10 .22 10 .24 10 .40 10 .40 8 .35 8 .50 6 .35 8 .70 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A, 125 No. 2328. No. 2330. No. 2332. No. 2336. No. 2338. No. 2340. No. 2342. No. 2348. No. 2354, No. 2356. 2328. CALIPEE, Inside. Polished steel. Length, 15 em. $0.35 2330. CALIPEE, Outside. Polished steel. Length 15 em 35 2332. CALIPEE, Double. Inside and outside. Polished steel. Length, 15 cm 40 2336. CALIPEE, Eegistering, Double. Inside and outside. Nickel-plated. Total length, 15 cm. 1.35 2338. CALIPEE, Spring, Inside. Even tension, solid nut. Polished steel. Length, 12.5 cm 1.00 2340. CALIPEE, Spring, Outside. Even tension, solid nut. Polished steel. Length, 12.5 em LOO 2342. CALIPEE, Micrometer, Metric. This caliper will measure all sizes up to 25 mm, and is gradu- ated to read to 0.01 mm. It is provided with a friction head so that all measurements are made with the same degree of pressure 6.50 2344. CALIPEE, Micrometer, Metric, for measurements up to 25 mm, graduated to read to 0.01 mm. Provided with a ratchet stop, same as No. 2348 7.50 2346. CALIPEE, Micrometer, Metric, for measurements up to 25 mm, graduated to read to 0.01 mm. Similar to No. 2344, but with neither friction head nor ratchet stop 6.50 2348. CALIPEE, Micrometer, English, for measurements up to 1 inch, graduated to read tc 0.001 in. Provided with ratchet stop 7.50 2350. CALIPEE, Micrometer, English, for measurements up to 1 inch, graduated to read to C.i/01 in. Similar to No. 2342, but with neither friction head nor ratchet stop 6.50 2352. CASE for Micrometer Caliper, covered with morocco leather and lined with velvet. Will hold either No. 2344, No. 2346, No. 2348 or No. 2350 75 2354. CALIPEE, Vernier, of steel; length, over 16 cm; the most complete vernier caliper on the mar- ket. Inside caliper, outside caliper and depth gauge combined. Graduated to 5 inches in 16th inch divisions and to 12 centimeters in millimeter divisions; reading by verniers to 1/128 inch and 1/10 millimeter. Thumb attachment for easy operation. Neat, accurate and durable 4.00 2356. CALIPEE, Vernier, of steel, same as No. 2354 with the addition of a micrometer screw adjustment. 6.00 2337. CASE for Vernier Caliper, leather. Will hold either No. 2354 or No. 2356. . .70 126 CENTBAL SCIENTIFIC CO., CHICAGO. U. S. A. No. 2360. No. 2376. CALORIMETERS No. 2378. 2360. CALORIMETER, Parr Standard, for determining the heat units in coal, coke, lignite and oils. The most rapid and convenient apparatus for measuring the calorific power of fuels. Requires no special skill in manipulation and no complicated connections to oxygen tanks, etc. Outfit is readily portable, being self-contained. Bequires power to operate stirrer, which can be fur- nished by water motor or electric motor. Determinations can be quickly made, requiring not more than 20 minutes to complete a test on a prepared sample. The bomb or combustion cup furnished! is made of a special alloy which resists the action of the melted sodium peroxide, and can be used continuously. An arrangement is made whereby the water is not admitted to contact with the. bomb until the fusion is completed, thus insuring the complete combustion of the sample. A further advantage of this calorimeter is the fact that sulphur and total carbon may be easily determined from the fused product of the combustion by the Sulphur Photometer (see No. 2378), and the Total Carbon Apparatus (see No. 2376). Two interchangeable fusion cups are furnished enabling duplicate determinations to be made. Complete with thermometer reading from 65° to 90°F. in 1/20° divisions with Bureau of Standards certificate, reading lens with support, two-liter measuring flask, chemical receptacle, measuring cup, 100-mesh 5 inch brass sieve with bottom, forceps, camel hair brush, ignition wire, chemicals sufficient for fifty determinations and battery for ignition, but without motor $85.00 Accessories and Parts for Parr Standard Calorimeter. 2361. ELECTRIC MOTOR, variable speed, for 110 volts A. C. or D. C. mounted on support 23.00 2362. ELECTRIC MOTOR, variable speed, for 220 volts A. C. or D. C. mounted on support 23.00 2363. WATER MOTOR and Support 5.00 13533 A. THERMOMETER, 65° to 90° F., in i,£0° divisions, with Bureau of Standards certificate. . . 12.00 13533B. THERMOMETER, 65.° to 105° P., in i£0° divisions, with Bureau of Standards certificate . . . 15.00 2366. ADJUSTABLE RHEOSTATS, for use with lighting circuit in place of battery to reduce voltage to safe limit for ignition. No ; A B For volts 110 220 Total resistance, ohms 50 90 Each ;... 7.50 8.50 2367. IGNITION WIRE for electric ignition per card .75 2368. BOMB for Electric Ignition, complete with wrenches 35.00 13730. READING LENS, with support 3.00 13731. READING LENS only, without support 2.00 2371. SODIUM PEROXIDE, a special quality put up for use with the Parr Calorimeter, in metal con- tainer. Size, pounds % % 1 Each 1.10 1.95 3.00 2372. ACCELERATOR per 2 ounce bottle 1.00 2373. GASKETS for bomb per dozen .40 2376. TOTAL CARBON APPARATUS, Parr, for total carbon in coal, coke, etc., in connection with the Parr Standard Calorimeter. By adding acid to the dissolved residue from the combustion, which appears as sodium carbonate, carbon dioxide is liberated and measured under proper conditions. Complete with full directions for use 52.00 2378. SULPHUR PHOTOMETER, Parr, for use in connection with the Parr Standard Calorimeter, for readily indicating the percentage of sulphur in coal, coke, and petroleum. The fused mass obtained from the calorimeter bomb is dissolved in water and the sulphur precipitated by means of barium chloride. From the depth of the liquid in the graduated tube at which the light from the flame disappears, a reading is obtained directly which indicates the percentage of sulphur in the sample ". 40.00 2379. BARIUM OXALATE for use with No. 2378 per 2 ounce bottle .75 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. 127 No. 2382. 2382. CALORIMETER, Parr Oxygen Bomb, a new instrument of the Berthelot-Mahler type with a bomb made of the new acid-resisting alloy lllium. This metal has proved by means of tests extending over several years to be equivalent to or better than platinum for calorimetric work. This feature renders unnecessary any costly lining of gold or platinum, and consequently makes the Parr outfit the most economical of the bomb calorimeters recognized as standard. The new bomb is also entirely free from the corrosion to which the platinum-lined steel bombs are sub- ject, and eliminates the annoyance due to the chipping and cracking of the enamel in porcelain- lined bombs. A rubber gasket is substituted for the lead of the old type, and a check valve with rubber seat replaces the needle valve. The calorimeter can is oval in shape permitting the use of a rotary stirrer which quickly distributes the heat and obviates any temperature lag. Complete with lllium bomb, water container, insulating vessel of indurated fibre with cover of same, rotary stirrer, pressure gage and needle valve with oxygen connection and couplings, octagon socket for bomb, spanner wrench, six capsules of special alloy, reading lens and sup- port, special ignition wire and gaskets, but without thermometer or motor. (See Report of the Joint Committee of the American Chemical Society and American Society for Testing Ma- terials, in the Journal of Industrial and Engineering Chemistry, Vol. IX, No. 1, for Januarv 1917) ". $285.00 Accessories and Parts for Parr Oxygen Bomb Calorimeter. 2361. ELECTRIC MOTOR, variable speed, for 110 volts A. C. or D. C 23.00 2362. ELECTRIC MOTOR, variable speed, for 220 volts A. C. or D. C 23.00 13533 A. THERMOMETER, 65° to 90° F., in Ho° divsions, with Bureau of Standards certificate. . . 12.00 13533B. THERMOMETER, 65° to 105° F., in H0° divsions, with Bureau of Standards certificate. . . 15.00 13519. THERMOMETER, Beckmann Differential, with range of o to 6 degrees graduated to Moo°c-» ^th Bureau of Standards certificate 32.50 2384. BOMB only of lllium alloy 210.00 2385. WATER CONTAINER 10.00 2386. INSULATING VESSEL, of fiber, with cover, stirrer and pulley 30.00 2387. PRESSURE GAGE, with needle valve, oxygen connections and couplings 6.50 2388. OCTAGON SOCKET for bomb " 3.50 2389. SPANNER WRENCH 6.50 13730. READING LENS, with support 3 00 13731. READING LENS only, without support 2 00 2367. IGNITION WIRE . . '. per card .75 2390. GASKETS for Valve. per dozen .90 2391. GASKETS for Union per dozen .25 2392. CAPSULES, of lllium alloy each 3.50 128 CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 2394. 2394. CALORIMETER, Parr Adiabatic Oxygen Bomb. An entirely new adiabatic system is employed which insures a degree of accuracy not possible with pneumatic or vacuum methods. Water is kept circulating constantly throughout the cover and on all sides of the jacket, the tempera- ture of which is under the positive control of the operator. By turning the proper valve, either cooler or warmer water is instantly admitted and immediately distributed throughout" the jacket permitting the operator to keep the temperature controlled in either direction to correspond absolutely with that in the calorimeter proper. This is a feature not found in any other commercial calorimeter. By this means errors due to radiation or to conductivity lag are eliminated and the use of calculations made unnecessary. The cover is pivoted so that it swings out of the way in a horizontal plane, carrying the thermometer with it, thus reducing the danger of breakage to a minimum. The water container and bomb are the same as those employed in the Oxygen Bomb Calorimeter No. 2382. Complete with water container, Illium bomb, adiabatic water jacket, rotary stirrers, pressure gage and needle valve with oxygen con- nection and couplings, octagon socket for bomb, spanner wrench, six capsules of special alloy, reading lens and support, special ignition wire and gaskets, but without thermometer, motor, heater, or heater burner $375.00 Parts and Accessories for Parr Adiabatic Oxygen Bomb Calorimeter. 2395. HEATER for water supply system 25.00 2397. HEATER BURNER 1.00 2398. ELECTRIC MOTOR, variable speed, for 110 volts A. C. or D. C 28.00 2399. ELECTRIC MOTOR, variable speed, for 220 volts A. C. or D. C 28.00 For other parts, see those listed under Parr Oxygen Bomb Calorimeter No. 2382. Note: — If desired by those who are accustomed to using only platinum lined bombs, we shall be glad to quote prices on a special platinum lined Illium bomb. The advantages of this over the usual platinum lined steel bomb are obvious. 2400. PELLET PRESS and Mold, complete, for preparing fuel pellets for calorimetric determinations 20.00 OXYGEN CYLINDERS for use with Oxygen Bomb Calorimeter, see Gas, Oxygen. CALORIMETERS, Gas, see Gas Analysis Apparatus. CANS, Sample, see Boxes. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 129 No. 2410. No. 2422. No. 2426 (shown in use) . No. 2428. 2408. CAPSULES, Best American Porcelain, as used in milk analysis, ash determination in flour, etc. No. 1 13 45 12 $0.25 3 25 69 13 .35 4 45 72 16 .40 2410. 2411. 2412. 2413. 2414. 2415. 2416. 2418. 2422. 2424. 2426. 2427. 2428. With straight sides and flat bottom, glazed throughout. Capacity, cc Diameter, mm Height, mm Each CAPSULES, Combustion, see Combustion Capsules. CARBON BATHS, see Water Baths. CARBON DISSOLVING TUBES, see Test Tubes. CARBON DIOXIDE DETERMINATION APPARATUS CARBON DIOXIDE APPARATUS, Barker, for the determination of carbonates in limestone, fertilizers, soda baking powders, etc. The outfit consists chiefly of a special hydrometer, in the bulb of which is a reservoir for acid and a reaction chamber for the carbonate. No bal- ances are required, as the change in weight is read directly in percentage of carbon dioxide on the graduated stem. It is suitable for any carbonate containing more than 5 per cent, car- bon dioxide, and permits an accuracy as great as in the standard laboratory method. A cer- tificate of accuracy is furnished with each outfit. Complete with special hydrometer, jar, thermometer, graduated cylinder, dropping pipette, and one pound of hydrochloric acid in glass stoppered bottle ; 12.00 HYDROMETER only of No. 2410 9.00 CARBON DIOXIDE APPARATUS ( Alkalimeter) , Bunsen's 1.20 CARBON DIOXIDE APPARATUS (Alkalimeter), Geissler's new form, with ground joint! . 1.20 CARBON DIOXIDE APPARATUS (Alkalimeter), Knorr's, for determination of carbonic acid in carbonates, especially baking powder, recommended by the Association of Official Agricultural Chemists. All joints are ground together 11.40 CARBON DIOXIDE APPARATUS, same as No. 2414, but with rubber connections instead of ground joints 9.00 CARBON DIOXIDE APPARATUS (Alkalimeter), Mchr's, with two ground joints 3.30 CARBON DIOXIDE APPARATUS (Alkalimeter), Schroedter's, with tube in flask 3.80 CARBON FILTER TUBES, see Filter Funnels. CARBOY, Glass, in rubber cushioned crate, capacity 5 gallons 3.50 CARBOY, Glass, boxed, capacity 10 gallons 10.00 CARBOY INCLINATOR, Flaherty's. A lever locks the carboy to the inelinator, and on account of the shape of the rockers the carboy always returns to an upright position when released. A very convenient method of tilting a heavy carboy 8.50 CARDBOARD, Bristol Board, best quality for drawing, in sheets 11x14 inches. . Each .05 Per dozen .35 CASSEROLES, Best American Porcelain, with lip and porcelain handle, glazed with exception of rim. No 1 3 3A 4 4A 5 6 7 Capacity, cc 30 75 150 210 375 500 750 1250 2000 Outside diameter, mm 50 70 85 95 110 120 135 165 175 Each 35 .40 .50 .70 .90 1.15 1.40 2.00 3.50 130 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 2430. No. 2432. No. 2448. 2480. 2432. 2434. CASSEROLES, Porcelain, lipped, with porcelain cover and wooden handle. Capacity, cc 125 250 375 500 Diameter, mm 90 105 110 120 Each $0.50 .60 .75 1.00 CASSEROLES, Agateware, with handle. Manufacturer 's rated capacity, ounces 16 Each 25 CASSEROLES, Opaque Fused Silica, with handle and lip. No A B C Capacity, cc 30 150 Diameter, mm 51 70 Depth, mm 25 35 44 Each . . 2.20 2.70 3.30 750 152 1.50 32 .30 D 200 95 51 4.25 1000 172 1.70 64 .36 E 350 108 63 5.50 2436. CATHETOMETERS, see CATALOG F OF PHYSICAL APPARATUS. CEMENT, ALUNDUM REFRACTORY, for use in repairing muffles, cores, electric furnaces, and in general wherever a refractory cement of high thermal conductivity is desirable. Used exten- sively for covering resistance wire in electric, furnaces. When mixed with water to make a thick paste it is ready for use. Furnished in three mixtures, RA 162 for general work, RA 355 where a fine grained cement is required, and RA 305, for use where a cement with a vitrifying point of 500° C. is needed. Unless specified when ordering, mixture RA 162 will be furnished. In lots of, pounds 1 5 10 Mixture RA 162 , 40 .75 1.30 Mixture RA 355 50 1.25 2.50 Mixture RA 305 50 1.25 2.50 CEMENT, Asbestos, see Asbestos Cement, No. 308. CEMENT, De Khotinsky Laboratory. This well-known cement is not attacked by water, sul- phuric, nitric or hydrochloric acids, bisulphide of carbon, benzine, gasoline or turpentine, and is very little affected by ether, chloroform, caustic alkalies, etc. Comes in small sticks of about 1 oz., large sticks of about 2 oz. and in bulk by the pound. Prepared in three different grades as follows: Hard for cementing glass, metal and porcelain; medium for cementing and in- sulating purposes; soft for insulating and covering electric wires, for condensers, static ma- chines, protection against corrosion and for cementing rubber, hard rubber, wood, ivory, etc. No A B C Size Small Stick. Large Stick. Pound. 2440. CEMENT, De Khotinsky Laboratory, Hard 2441. CEMENT, De Khotinsky Laboratory, Medium. 2442. CEMENT, De Khotinsky Laboratory, Soft. . . . .55 .55 .55 1.10 1.10 1.10 6.60 6.60 6.60 2443. CEMENT, De Khotinsky Black, Medium. For imitating Niello or producing decorations on metals by filling in engraved lines, letters, and figures. This cement does not shrink or sink below the surface of the metal with time, and after polishing gives the luster and appearance of black enamel. In sticks of about J/£ ounce Per stick .30 2444. CEMENT, De Khotinsky Black, Soft, similar to No. 2443, but with a lower melting point. In sticks of about % oz Per stick .30 2446. CEMENT, Loxol, for joining or mending china, glass, metal, wood, and for electrical insulation. In 8 oz. cans Per can .50 2448. CEMENT, Quixo or Liquid Porcelain. When dry it is not affected by fire or water. K will cement all articles except India rubber, vulcanite, celluloid and black-lead. Excellent for build- ing aquaria, making labels, etc. In 6-ounce cans Per can .25 CEMENT. Rubber, see Rubber Cement. CENTBAL SCIENTIFIC CO., CHICAGO. U. S. A. 131 No. 2466. No. 2460. No. 2462D. CEMENT TESTING APPARATUS AUTOCLAVES for Cement, see general heading Autoclaves. BALANCES for Cement, see general heading Balances. 2454. BRIQUETTE MOLD, American Society for Testing Materials Type, of brass with end clamps $3.50 2456. BRIQUETTE MOLD, American Society for Testing Materials Type, of brass with iron horseshoe clamp 3.50 2457. IRON HORSESHOE CLAMP only for No. 2456 40 2460. BRIQUETTE MOLD, Improved Form, American Society for Testing Materials Type, for separ- ating sections without rapping $3.50 2462. BRIQUETTE GANG MOLDS, American Society for Testing Materials Type, of brass with end and center clamps. No A B C D E Number of briquettes 23456 Each 7.00 10.00 13.50 16.50 20.00 2464. BRUSH, of brass wire in wood handle for cleaning briquette molds. Length of brush portion, 5 inches 75 2466. COMPRESSION TESTING MACHINE, Olsen's Hydraulic Hand Power, designed to meet the de- mand for a low priced compression machine for cement and concrete. The pressure is obtained by forcing a cylindrical ram into the oil cylinder of the machine by means of a hand wheel and worm gear. A spherical bearing is employed in mounting the table which enables it to adjust itself to the faces of the specimen in order to transmit the pressure uniformly. The load on the specimen at all times is shown by a hydraulic gage connected to the oil cylinder. The platens are scribed with concentric circles to facilitate centering the specimen and are large enough to hold a 6 inch cube, with an extreme distance of 6% inches between faces. Size of machine: 30 inches long, 30 inches wide and 72 inches high. Weight, 1000 pounds. Capacity, 40,000 pounds F. O. B. Philadelphia 350.00 Note: — This machine is furnished to order only and we cannot promise immediate delivery. 132 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 2478. No. 2470. No. 2476. 2468. GILLMORE NEEDLES in block, for determining both the initial and the final set of cement. They consist of a pair of steel needles, one, i/j2 inch in diameter loaded with a weight of Vi pound, and the other i£4 inch in diameter loaded with a weight of one pound $6.00 2470. GILLMORE NEEDLES, same as No. 2468, but with vertical support to keep the needles perpen- dicular to the surface of the pat '. 6.00 MOIST CHAMBER for Cement, of soapstone, furnished to order. Prices on application. 2472. MOLDS, Cylindrical, brass, for preparing cylinders used in determining the compressive strength of Portland cement mortars. Diameter, 2 inches; height, 4 inches. (See Tentative Standard of the American Society for Testing Materials C 9 — 16 T) 8.00 2473. TAMPER, Steel, for use with No. 2472. Weight, about % pound; length, 6% inches; diameter at top, % inch; at bottom, 1 inch 3 50 2476. MOLD, Cylindrical, cast iron, with detachable base plate and hinged clamps, machined to size. Diameter, 8 inches; depth, 16 inches 27.50. 2478. MOLDS, Cube, of brass, with hinge clamp for preparing cubes for compression tests. No A B For cubes, inches 1 2 Each 3.50 4.50 2480. MOLD, Cube, of iron, hinged, for 6 inch cubes, with detachable base plate 9.00 2482. MOLDS, Cube, of brass, same as No. 2478, but in gangs of 2 molds. No A B For cubes, inches 1 2 Each 3.00 4.00 2486. MOLD, Pat, for forming pats of neat cement intended for steaming tests 2.50 2488. PAN, of galvanized iron, for immersing briquettes in water before testing. Size, 24x24x3 inches 1.50 2490. PLATE, of heavy glass, for use in mixing cement and filling briquette molds. Size, 24x24 inches „ 4.50 SAMPLE CANS for Cement, see Boxes No. 1828. 2496. SAND, Standard, for cement testing, according to the American Society for Testing Materials per 100 pound bag 4.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 133 No. 2500. No. 2512. No. 2498. 2498. SOUNDNESS TEST APPARATUS, Le Chatelier, for indicating the soundness of cement by its expansion after being boiled $3.50 2500. SPECIFIC GRAVITY APPARATUS, Jackson's, for the accurate determination of the specific gravity of cement. Consists of a special burette calibrated to give specific gravity readings directly, and a special flask with ground in funnel. (See Journal of the Society of Chemical Industry, Vol. XXIII, Xo. 11, for June 15, 1904) 7.00 SPECIFIC GRAVITY BOTTLES for Cement, see Bottles, Specific Gravity. 2502. STEAMING APPARATUS, of polished copper, tinned on inside, for boiling and steaming cement specimens for determining soundness. Size, 15x15x30 inches. Mounted on sheet iron support, with shelf of wire screen and gas burner 37.50 1614G. CONSTANT LEVEL BOTTLE for use with No. 2502. Capacity, 2 gallons 3.00 2504. TAMPER for uniformly packing cement in briquette molds 12.00 2506. TESTING MACHINE, Olsen New Automatic, for tension tests, the latest type of automatic shot cement tester. The shot is used to counterbalance the heavy weight, and when it is removed the tension produced is applied to the briquette. The shot is caught in a container on a bal- ance which indicates on a special graduated dial the force applied up to the time of rupture, when the flow of shot is automatically shut off. The action and weighing of shot is absolutely automatic, requiring no reweighing to determine the load applied. Size: 24 inches long, 10 inches wide, and 30 inches high. Weight, 150 pounds; capaeitv, 1000 pounds. P. O. B. Philadelphia 200.00 Note: — This machine is furnished to order only and we cannot promise immediate delivery. 2508. TESTING MACHINE, Olsen Improved Automatic, for tension tests. Same as No. 2506," but pro- vided with a crank in the base for applying a steady tension to the briquette in order to hold the beam in equilibrium throughout the test. Size: 40 inches long, 11 inches wide and 36 inches high. Weight, 170 pounds; capacity, 2000 pounds F. O. B. Philadelphia 350.00 Note: — This machine is furnished to order only and we cannot promise immediate delivery. 2509. LEAD SHOT for use with Xos. 2506 and 2508 per25 pound bag 5.00 2512. TROWELS for mixing cement. Length of blade, inches 3 4 Each 50 .60 2514. VIC AT NEEDLE APPARATUS, Bramwell Improved Form, for determining the normal consist- ency and setting time of cement according to the methods recommended by the American Society for Testing Materials. The needles are on opposite ends of the 300 gram plunger rod, the change being made by reversing the rod. Diameter of large needle, 1 cm; diameter of small removable needle, 1 mm 20.00 2515. RUBBER MOLD onlv for No. 2514 3.00 134 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 2534. No. 2536. No. 2524. No. 2542. CENTRIFUGES CENTRIFUGES, HAND AND WATER MOTOR 2524. CENTRIFUGE, Hand Driven, high speed, giving from 1,000 to 3,000 revolutions per minute, for the rapid and accurate analysis of urine, sputum, blood, pus, milk and the precipitation of solids in any liquid. The case is of iron, well finished, the bearings accurate, the gear wheels cut by special machinery, and the pitch so calculated as to render the machine almost noiseless. Com- plete with two aluminum shields, one each 15 ec plain and graduated glass tubes $11.00 2526. CENTRIFUGE, Hand Driven, same as No. 2524, but with arm for holding four tubes. Complete with four aluminum shields, two each 15 ce plain and graduated tubes. This machine is capable of doing the work of two ordinary centrifuges 17.25 2528. CENTRIFUGE, Hand Driven, samo as No. 2524, with two tubes for the examination of urine and with haematocrit for the examination of blood and sputum 18.00 2530. CENTRIFUGE, Hand Driven, same as No. 2526, with four tubes for the examination of urine and with haematocrit for the examination of blood and sputum 22.50 2532. CENTRIFUGE, Water Motor, for attachment to ordinary smooth faucet. Speed is controlled by flow of water. So constructed that bearings cannot become rusted nor can oil be washed out. Noiseless in operation. Each machine is furnished with aluminum shields, 3 feet pressure tub- ing, and hose connection for attachment to smooth faucet. Complete with 2-tube 15 cc head, two aluminum shields, and one each 15 cc plain and graduated glass tubes 12.00 2534. CENTRIFUGE, Water Motor, same as No. 2532, but with four-tube 15 ce head, four aluminum shields, and two each 15 ce plain and graduated glass tubes 18.80 2536. CENTRIFUGE, Water Motor, same as No. 2532, but with two-tube 50 cc head for the examina- tion of kerosene or liquids where larger quantities are to be tested. Complete with aluminum shields, and two 50 cc graduated glass tubes 21.00 Accessories for Hand and Water Motor Centrifuges. 2537. TWO-TUBE HEAD for 15 cc tubes, without shields or glass tubes 4.35 2538. FOUR-TUBE HEAD for 15 ce tubes, without shields or glass tubes 6.85 2539. TWO-TUBE HEAD for 50 ce tubes, without shields or glass tubes 7.80 2540. FOUR-TUBE HEAD for 50 ce tubes, without shields or glass tubes 13.80 2541. TWO-TUBE HEAD, Goetz, for phosphorus determinations in steel, with metal shields, but with- out glass ware 12.60 2542. HAEMATOKRIT, with two tubes each for examination of blood and sputum 7.25 2543. PERCENTAGE TUBE for Blood Analysis, for No. 2542 90 2544. SPUTUM TUBE for No. 2542 36 2545. DROPPER, new construction, for filling the blood tubes 25 2546. GRADUATED URINE TUBES, 15 cc each .65 per dozen 6.50 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 135 2547. 2548. 2549. 2550. 2551. 2552. 2553. 2554. 2555. 2557. 2558. 2559. get No. 2548. No. 2551. No. 2553. No. 2555. No. 2556. No. 2570. PLAIN URINE TUBES, 15 cc each $0.20 per dozen 2.00 GRADUATED TUBE, length 4^ inches, outside diameter ii^c inch, graduated to 10 ec. . . .40 PLAIN TUBE, same as No. 2548, but ungraduated, length of tube 4% inches, outside diametef ll/10 inch .20 ALUMINUM SHIELD for 15 ce tubes 30 GOETZ TUBE for phosphorus determinations, with graduated tip 1.10 METAL SHIELD for carrying No. 2551 Goetz Tube 1.10 CEMENT TUBE, with 50 cc graduation, with tip graduated to %o ce, for cement testing and for use where the proportion of sediment is extremely small 1.50 METAL SHIELD, for carrying No. 2553 Cement Tube 1.10 TUBE FOR MILK ANALYSIS, graduated for obtaining a reliable test of either breast or cow's milk. It will give results accurate to within i£ of 1 per cent, of fat 65 CONICAL TUBE, graduated to 50 cc, for use in testing kerosene and other liquids where larger quantities are to be tested than can be carried in a 15 ee tube 1.00 CONICAL TUBE, plain, same as No. 2556 without graduations 50 ALUMINUM SHIELD for carrying Nos. 2556 and 2557 85 SPEED INDICATOR 3.00 CENTRIFUGES for Oil, see Oil Testing Apparatus. CENTRIFUGES, ELECTRIC CENTRIFUGES, VICTOR After a careful investigation we have selected the Victor line of electric centrifuges because of their superiority in the following important respects: — 1. The electric motor, which is the heart of any centrifuge, is carefully made, obviating any elec- trical troubles, such as burn-outs, overheating, loose contacts, etc. 2. The shaft is accurately centered, preventing vibration. 3. The motor is so wound that by shifting a single contact in the base, it can be changed from an A. C. to a D. C. motor. It is not a universal motor. 4. The centrifuge head is carefully balanced and weighted so as to produce a smooth uniform mo- tion, without any jerk in starting or stopping. 5. The relation between speed, weight, and centrifugal force has been worked out with mathe- matical exactness so that one can instantly determine what centrifuge to procure in order that a given force may be exerted on the suspended particles. 6. The construction and finish of these centrifuges are such as to afford the greatest protection from chemical reagents. 7. A complete line of accessory parts, including glassware, is available. 2570. CENTRIFUGE, Victor No. 3, with motor entirely enclosed in enameled iron jacket. Can be operated on either 110 volt A. C. or D. C. by shifting a single connection in the base. Complete with two-tube head of heavy construction, with attached trunnion rings, two conical aluminum shields for 15 cc tubes, and attachment cord and plug, without glassware. Specifications : — • Height over all, 12 inches. B. P. M. (A. C.) 1500. Width over all, rotating, 15 inches. Relative force (times gravity) 325. Weight, 23 pounds. R. P. M. (D. C.) 1800. Average spread, 26 cm. Relative force (times gravity) 469. Price $32 00 2572. CENTRIFUGE, Victor No. 3, same as No. 2570, but arranged for 220 volts A. C. and D. C. 35.00 136 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 2580 with No. 2588. 2574. CENTRIFUGE, Victor No. 3, same as No. 2570, but equipped with four-tube head and four aluminum shields for 15 ec tubes, without glassware. Specifications same as No. 2570, except: — B. P. M. (A. C.) 1350. R. P. M. (D. C.) 1400. Relative force 264. Relative force 286. Price $34.50 2576. CENTRIFUGE, Victor No. 3, same as No. 2574, but arranged for 220 volts A. C. and D. C. 37.50 2578. RHEOSTATS for controlling speed of No. 3 Centrifuges. No A B For volts 110 220 Each 3.60 3.60 For other ACCESSORIES, see list at end of section on Victor Centrifuges. 2580. CENTRIFUGE, Victor No. 2, similar to No. 2570, but of heavier construction, can be operated at a higher speed, will handle larger volumes of liquid, and has a rheostat in the base by means of which three different speeds may be obtained. The motor, arranged for both 110 volts A. C. and D. C., is entirely enclosed in an iron jacket, enameled with black acid-proof finish. Com- plete with two-tube head with attached trunnion rings, two conical aluminum shields for 15 cc tubes, and attachment cord and plug, without glassware. Specifications : — Height over all, 15 inches. R. P. M. (A. C.) with Protective Dome No. 2588, 2800. Diameter over all, 10 inches. Relative force, 780. Weight, 22V2 pounds. R. P. M. (D. C.) with Protective Dome No. 2r>8S, 3300. Average spread, 18 em. Relative force, 1050. Price 43.70 2582. CENTRIFUGE, Victor No. 2, same as No. 2580, but arranged for 220 volts A. C. and D. C. 46.70 2584. CENTRIFUGE, Victor No. 2, same as No. 2580, but with four-tube head with attached trunnion rings, four conical aluminum shields, and attachment cord and plug, without glassware. Specifications : — Height over all, 15 inches. R. P. M. (A. C) with Protective Dome No. 2588, 2.100. Diameter over all, 10 inches. Relative force 620. Weight, 22i/2 pounds. R. P. M. (D. C.) with Protective Dome No. 2588, 3000. Average spread, 18 cm. Relative force 900. Price 47.50 2586. CENTRIFUGE, Victor No. 2, same as No. 2584, but arranged for 220 volts A. C. and D. C. 50.50 2588. PROTECTIVE DOME, of heavy spun copper, polished, with closely fitting lid with handle. Can be easily attached to any Victor No. 2 Centrifuge. The use of this dome permits a higher speed, and eliminates danger to the operator 10.50 Accessories for No. 2 Centrifuges. 2589. TWO-TUBE HEAD, with attached trunnion rings and 50 cc round bottomed bronze shields, with rubber cushions 9.70 2590. TWO-TUBE HEAD, with Babcock trunnion cups and rubber cushions, for determining the per- centage of butter-fat in milk or cream 11.40 For other ACCESSORIES, see list at end of section on Victor Centrifuges. CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 137 2596. 2598. 2600. 2602. 2604. 2606. 20"-. Nos. 2594-2608. CENTRIFUGE, Victor No. 4, for heavy work and wide range of speed. The motor, arranged for both 110 volts A. C. and D. C., is entirely shut off from the centrifuge chamber, eliminating any danger of ignition of combustible vapors from sparking. The protective dome is cast as an integral part of the motor housing, and is provided with a heavy hinged lid. A rheostat in the base permits five different ranges of speed. A variety of multiple tube heads may be used and greater speed can be obtained than with the No. 2 or No. 3. Complete with four-tube head with attached trunnion rings, four 15 cc round bottomed bronze shields with rubber cushions, and attachment cord and plug, without glassware. Specifications : — R. P. M. (A. C.),2300. Relative force (times gravity), 830. R. P. M. (D. C.), 2700. Relative force (times gravity), 1140. Height over all with cover closed, 18% inches. Height over all with cover open, 29% inches. Width over all, 18% inches. Weight, 100 pounds. Average spread, 28 cm. Price . $105.70 CENTRIFUGE, Victor No. 4, same as No. 2594, but arranged for 220 volts A. C and D. C. 109.20 CENTRIFUGE, Victor No. 4, same as No. 2594, but with eight-tube head with attached trunnion rings and eight 15 ce round bottomed bronze tubes with rubber cushions. Specifications same as No. 2594, except: — R. P. M. (A. C.), 2300. R. P. M. (D. C.), 2600. Relative force (times gravity), 830. Relative force (times gravity), 1060. Price ." 113.15 CENTRIFUGE, Victor No. 4, same as No. 2598, but arranged for 220 volts A. C. and D. C. 116.65 CENTRIFUGE, Victor No. 5, similar in construction to No. 2594, but with specially powerful motor, designed to take care of all work from the lightest to the very heaviest. The motor, aranged for both 110 volt A. C. and D. C., is enclosed in the same frame as the No. 4, but is capable of a much wider range of speed. Complete with five point rheostat for regulating speed, large oil wells easily accessible, four- tube 15 ce head with attached trunnion rings, four 15 ce round bottomed bronze tubes, and attachment cord and plug. Specifications : — Height over all with cover closed, 18% inches. Height over all with cover opened, 29% inches. Diameter over all, 18% inches. Weight, 105 pounds. Average spread, 28 cm. Price 118.20 CENTRIFUGE, same as No. 2602, but arranged for both 220 volts A. C. and D. C 121.20 CENTRIFUGE, same as No. 2602, but with eight-tube 15 cc head with attached trunnion rings, and eight 15 cc round bottom bronze tubes with rubber cushions. Specifications same as No. 2602, except: — R. P. M. (A. C.), 3400. R. P. M. (D. C.), 3600. Relative force, 1810. Relative force, 2000. Price 125.65 CENTRIFUGE, same as No. 2606. but arranged for both 220 volts A. C .and D. C 128.65 R. P.M. (A. C.), 3700. Relative force (times gravity), 2140. R. P. M. (D. C.), 4000. Relative force (times gravity), 2460. 138 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 2615. No. 2632. No. 2633. No. 2634. No. No. No. No. No. No. No. 2635. 2649. 2650. 2651. 2652. 2653. 2656. 2611. 2612. 2613. 2614. 2615. 2616. 2619. 2627. 2628. 2629. 2630. 2631. 2632. 2633. 2634. 2635. 2646. 2647. 2648. 2649. 2650. 2651. 2652. 2653. 2656. 2657. 2658. 2659. Accessories for Nos. 4 and 5 Victor Centrifuges. FOUR-TUBE HEAD, with attached trunnion rings and four 15 ce round bottomed bronze tubes with rubber cushions • $10.20 FOUR-TUBE HEAD, with attached trunnion rings and four 50 ec round bottomed bronze tubes with rubber cushions 15.10 EIGHT-TUBE HEAD, with attached trunnion rings and eight 15 cc round bottomed bronze tubes with rubber cushions 17.65 EIGHT-TUBE HEAD, with attached trunnion rings and eight 50 ce round bottomed bronze tubes with rubber cushions 26.45 FOUR-TUBE COMBINATION HEAD, with trunnion rings, two 15 cc and two 50 ec round bot- tomed bronze tubes with rubber cushions 12.65 EIGHT-TUBE COMBINATION HEAD, with trunnion rings, four 15 cc and four 50 cc round bot- tomed bronze tubes with rubber cushions 23.05 TRUNNION RINGS for Heads Nos. 2611 to 2616. No A B For tubes, cc 15 50 Each 35 .90 Assessories Which Can Be Used With Victor Centrifuges Nos. 2, 4, and 5. BRONZE SHIELD, round bottom, for 50 cc glass tubes for use with No. 2619B Trunnion Ring, including Bubber Cushion No. 2628 75 RUBBER CUSHIONS for No. 2627 Shield each .18 per dozen 1.80 BABCOCK TRUNNION CUP for use with Heads Nos. 2589, 2612 and 2614, including No. 2630 Cushion 1.50 RUBBER CUSHIONS for No. 2629 Cup each .15 per dozen 1.45 BUSHING for reducing size of No. 2627 Shield to take 15 ce tubes 60 GLASS TUBES, 50 ec, plain, with lip each .15 per dozen 1.50 GLASS TUBES, 50 ce, graduated each .80 per dozen 8.00 GLASS TUBES, 50 cc, plain, narrow neck each .20 per dozen 2.00 HART CASEIN GLASS TUBES, 50 cc each .50 per dozen 5.00 BABCOCK MILE TEST BOTTLES, see Milk Testing Apparatus. Accessories Which Can Be Used With Any Victor Centrifuge. ALUMINUM SHIELD for 15 cc glass tubes, with conical bottom 35 BRONZE SHIELD for 15 cc glass tubes, with round bottom and rubber cushion 55 RUBBER CUSHIONS for No. 2647 Shields each .15 per dozen 1.50 GLASS TUBES, 15 cc, plain, with conical bottom each per dozen GLASS TUBES, 15 cc, plain, round bottom each .15 1.50 .10 per dozen 1.10 GLASS TUBES, 15 cc, graduated, with conical bottoms each per dozen GLASS TUBES, 15 cc, plain with narrow neck each .55 5.50 .20 per dozen 2.00 HOPKINS VACCINE TUBES, 10 ec each 2.20 per dozen 22.00 BABCOCE TEST TUBES for human milk each .90 per dozen 9.90 RUBBER CAPS for Tubes Nos. 2649, 2650, and 2651 each .20 per dozen 2.20 SPEED INDICATOR 3.30 PEDESTAL, specially designed for Victor Centrifuges. Dimensions: height, 19 inches; spread over all, 24 inches; diameter of top, 14% inches i 26.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 139 2670. 2672. 2674. 2676. 2677. 2678. 2679. 2680. 2681. 2082. 2683. Nos. 2670-6. CENTRIFUGES, INTERNATIONAL INTERNATIONAL CENTRIFUGES are so well known as to need no comment. The ones listed below are those which have proved most adapted to laboratory needs and will cover practically every requirement of the scientific worker. They are carried in stock for prompt shipment. Prices upon any others not listed will be furnished upon request, and deliveries can be made within a reasonable length of time. The centrifuges are mounted in a heavy bell shaped casting which furnishes at the same time a rigid base, a protective housing and a strong bearing for the motor. Ample provision is made for oiling. The lower end of the shaft of the motor runs on a ball step immersed in oiL A speed control rheostat is supplied with each centrifuge. The prices of the centrifuges whose description follows, do not include heads or equipment. Select the ones adapted to your needs from the list of accessories. We carry in stock parts for which there is the greatest demand. Other types or parts will be obtained upon short notice. CENTRIFUGE, International No. 1, Type B, for 110 volts alternating current. With rheostat for speed control, but without heads or tubes. Specifications: — Height, cover closed, 23 inches. Height, cover open, 33 inches. Diameter, 17 inches. Shipping weight, about 270 pounds. Speed with four-tube 15 ce head and tubes, 3600 r. p. m. Relative force times gravity, 2015. Average spread, 28 cm. Speed with eight-tube 50 cc head and tubes, 3000 r. p. m. Relative force, 1600. Average spread, 32 cm. Speed with Board of Health Head, 3000 r. p. m. Relative force, 900. Average spread, 18 cm. Price $117.60 CENTRIFUGE, International No. 1, Type B, current CENTRIFUGE, International No. 1, Type B, speed control but without heads or tubes. Specifications : — Height, cover closed, 18 inches. Height, cover open, 28 inches. Diameter, 17 inches. Shipping weight, about 160 pounds. Speed with four-tube 15 cc head and tubes, 4000 r. p. m. Relative force times gravity, 2491. Average spread, 28 cm. Price . same as No. 2670, but for 220 volts alternating 117.60 for 110 volts direct current. With rheostat for Speed with eight-tube 50 cc head and tubes, 3000 r. p. m. Relative force times gravity, 1600. Average spread, 32 cm. Speed with Board of Health Head, 3000 r. p. m. Relative force, 900. • Average spread, 18 cm. 102.00 CENTRIFUGE, International No 1, Type B, same as No. 2674, but for 220 volts direct current 105.60 Accessories for International Centrifuge No. 1, Type B. Two-Tube 15 cc Head and attached trunnion rings 3.60 Four-Tube 15 cc Head and attached trunnion rings 8.40 Eight-Tube 15 cc Head and attached trunnion rings 14.40 Two-Tube 50 cc Head only without trunnion rings 4.20 Four-Tube 50 cc Head only without trunnion rings 8.40 Four- Tube Combination Head, with two attached 15 cc trunnion rings only and places for two 50 cc trunnion rings 8.40 Eight-Tube Combination Head, with four attached 15 cc trunnion rings only and places for four 50 cc trunnion rings ' 15.60 140 CENTEAL SCIENTIFIC CO., CHICAGO, IT. S. A. 2684. 2685. 2686. 2687. 2688. 2689. 2696. No. 2696. Two-Place Head only for Goetz tubes or separatory funnels $4.20 Eight-Tube 50 cc Head only 14-40 Board of Health Disk, without tubes 14.40 Bronze Basket, 5 inches in diameter, perforated, with copper drip can 26.40 Cast Iron Stand for mounting No. 1 Centrifuge 13.20 Two-Bottle Shaker Head for use on No. 1 Centrifuge 24.00 CENTRIFUGE, International No. 2, similar in construction to No. 2670, but larger, affording greater capacity and rendering available more varied equipment. The same equipment of heads and tubes may be used and in addition 100 cc tubes swung in the eight-tube head; also a sixteen-tube head carrying 50 cc tubes or Babeock test bottles. In addition a two-place or a four-place head for Squibb 's separatory funnels of about 150 cc capacity may be used. Other combinations will be found in the list of accessories which follows. Equipped with hand brake for bringing quickly to rest, and device for lifting brushes permitting a very gradual decrease in speed in coming to rest. Complete with rheostat for speed control but without head or tubes, with motor for 220 volts alternating current. Specifications : — Height, cover closed, 28 inches. Height, cover open, 40 inches. Diameter, 24 inches. Shipping weight, about 450 pounds. Speed with 16-tube 50 ee head and tubes, 2000 r. p. m. Eelative force, 954. Average spread, 43 cm. Speed with 8-tube 100 cc head and tubes, 2200 r. p. m. Relative force, 1077. Average spread, 40 cm. Speed with 8-tube 50 cc head and tubes, 3100 r. p. m. Relative force, 1708. Average spread, 32 cm. Speed with Board of Health Head, 3000 r. p. m. Relative force, 900. Average spread, 18 cm. Speed with 4-tube 250 ce head and tubes, 2400 r. p. m. Relative force, 1152. Average spread, 36 cm. Price 186.00 2698. CENTRIFUGE, International No. 2, same as No. 2696, but for 220 volts alternating current. 186.00 2700. CENTRIFUGE, International No. 2, same as No. 2696, but for 110 volts direct current 186.00 2702. CENTRIFUGE, International No. 2, same as No. 2700, but for 220 volts direct current 186.00 Accessories for International Centrifuge No. 2, in Addition to those Listed under Centrifuge No. 1. 2704. Two-Place Head only for Goetz tubes or separatory funnels 7.20 2705. Four-Place Head only for Goetz tubes or separatory funnels 11.50 2706. Eight-Tube Combination Head only for 6 small tubes and 2 Goetz tubes or funnels 18.00 2708. Sixteen-Tube Head only, for 15, 50 or 100 ce tubes, or Babcoek test bottles 22.80 2709. Bronze Basket, 11 inches in diameter, perforated, with copper drip-can 42.00 2710. Metal Shield for 100 cc tubes, Cornell style, with rubber cushion 90 2711. Trunnion Ring for 100 cc tubes 48 2712. Long Metal Cup for 9 inch Babeock bottles in head No. 2708 only, with rubber cushion 90 2713. Special Long Metal Cup for 9 inch Babeock bottles in Heads Nos. 2681, 2685, and 2706, with rub- ber cushion 1.32 2714. Metal Shield for 100 ce Oil Tube No. 2717, with rubber cushion 1.50 2715. Trunnion Ring for Metal Tubes Nos. 2712, 2713, and 2714 48 2716. Glass Tubes, 100 cc, plain, lipped each .25 per dozen 2.30 2717. Glass Oil Tubes, 100 cc, graduated each 3.00 per dozen 30.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 141 No. 2770. 2718. Rubber Cushions for 100 cc Shield, Cornell style each $0.30 per dozen 2.88 2719. Rubber Cushions for 100 cc Oil Tubes No. 27*17 each .55 2720. Cast Iron Stand for mounting No. 2 Centrifuge 14.40 2721. Four-Bottle Shaker Head for use on No. 2 Centrifuge 28.80 Accessories for Both No. 1 and No. 2 International ^Centrifuges. LlTL'S. Metal Shield for 15 ec glass tubes, Cornell style, with rubber eusfiion 65 2729. Reducing Cap for use with 15 ec glass tubes in 50 cc metal shields 18 2730. Metal Shield for 50 ce glass tubes, Cornell style, with rubber cushion 80 2731. Trunnion Ring for 15 cc tubes ". 55 2732. Trunnion Ring for 50 ce tubes 48 2733. Babcock Test Trunnion Cup, with rubber pad, for use in place of 50 ce tubes .72 2735. Square Trunnion Cup for Sputum Bottle No. 2757 for use in place of 50 ec tubes 94 2736. Trunnion Carrier for 150 cc Squibb separatory funnels, for use with Heads Nos. 2704 and 2705 2.40 2737. Trunnion Carrier for Goetz phosphorus tubes for use with Heads Nos. 2704 and 2705 2.20 2738. Glass Tubes, 15 cc, plain each .20 per dozen 1.92 2739. Glass Tubes, 15 cc, graduated in ^J0 divisions each .60 per dozen 5.76 2740. Glass Tubes, 15 cc, round bottom, plain each .12 per dozen 1.20 2741. Glass Tubes, 15 cc, narrow neck each .25 per dozen 2.35 2742. Hopkins Vaccine Tubes, 10 cc, for use in Metal Shield No. 2728 each 1.45 2743. Babcock Test Tubes for human milk, for use in Metal Shield No. 2728 each .55 per dozen 5.50 2744. Glass Tubes, 50 cc, plain, lipped each .25 per dozen 2.20 2745. Glass Tubes, 50 cc, plain, narrow neck each .20 per dozen 2.20 2746. Glass Tubes, 50 cc, graduated in *£ cc divisions to 10 ec; in 1 ee divisions to 50 ce.each .90 per dozen 9.00 2747. Hart Casein Tubes for use in Metal Shields No. 2730 each .60 per dozen 5.76 2748. Squibb Glass Separatory Funnel, 150 cc, for use in Trunnion Carrier No. 2736 2.85 2749. Goetz Glass Phosphorus Tube, with stopper, for use in Trunnion Carrier No. 2737 2.30 2~r>0. Board* of Health Glass Tubes, 2 cc per hundred 5.70 2751. Rubber Stoppers for Board of Health Tubes per hundred 2.20 2752. Board of Health Tubes, set of 20, with 40 stoppers » . , per set 2.40 2753. Rubber Cushions for 15 cc shields, Cornell style per dozen 1.08 L'7.~>4. Rubber Cushions for 50 cc shields, Cornell style per dozen 2.20 2755. Rubber Caps for Tubes Nos. 2738, 2739 and 2740 per dozen 1.08 2756. Molded Soft Rubber Caps for Glass Tubes No. 2745 per dozen 1.15 2757. Square Sputum Bottles, with corks per dozen .73 per gross 6.80 2758. Speed Revolution Counter 1.80 2770. CENTRIFUGAL MACHINE, Hand, for chemical use, consisting of Milk Testing Centrifuge No. 9204C, fitted with a heavily tinned perforated copper basket 7% inches in diameter and 3^4 inches deep, with % inch flange at the top. Can be used for a variety of purposes, such as dry- ing crystals, etc. Where corrosive materials are used, the inside of the iron case should be coated with some resistant material, such as paraffine or acid-proof varnish. The case is pro- vided with an outlet at the bottom for draining 25.00 CENTRIFUGES, Babcock or Milk Testing, see Milk Testing Apparatus. CENTRIFUGE, International Board of Health, see Milk Testing Apparatus. CENTRIFUGES, Soil, see Soil Analysis Apparatus. CENTRIFUGES, Moisture Equivalent, seo Soil Analysis Apparatus. 142 CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 2772. No. 2782. 2772. CENTRIFUGAL MACHINES, of acid proof construction, with basket and drip-can of porcelain. Especially adapted for determining yield of sugar in refinery laboratories, and for drying crystals in the experimental manufacture of chemical salts. The centrifuge is housed in a cast iron frame with enclosed direct connected motor with special bearings. The cast iron drain- ing chamber has an outlet at the bottom and the base is cut away to allow a collecting jar to be placed beneath the outlet. Complete with rheostat for speed control, perforated porcelain basket 6 inches in diameter, porcelain drip-can and interchangeable four-tube head with set of 10 cc plain glass tubes. Dimensions: height over all with cover closed, 22 inches; with cover open, 34% inches; diameter of cast iron chamber outside, 11 inches; maximum speed permis sible with" porcelain basket, 2500 r. p. m.; speed with four-tube head, 3000 r. p. m.; shipping weight, 160 pounds. No A B C D A. C. D. C. For volts 110 220 110 220 Each $128.70 128.70 128.70 128.70 Note: — If larger centrifuges are desired than the preceding, information will be furnished and prices quoted upon receipt of specifications giving purpose for which used, size of basket or number of tubes speed desired, character of driving power, etc. Accessories for Centrifugal Machine No. 2772. 2774. Perforated Porcelain Basket, 6 inches in diameter 23.10 2775. Porcelain Draining Chamber for use with No. 2774 19.80 2776. Perforated Bronze Basket, 8 inches in diameter 113.30 2777. Four-Tube Head, with metal shields for 10 cc tubes, with rubber cushions 13.20 2778. Four-Tube Combination Head, with 2 metal shields for 10 cc tubes and 2 trunnion cups for Gooch crucibles 14.85 2779. Hard Rubber Collars for Gooch crucibles • per pair 2.75 Note: — Gooch Crucibles must be sent in to bo fitted to No. 2779, as they vary in size. 2782. CENTRIFUGAL MACHINE, Sharpies Super-Centrifuge, gear driven, for hand power or belt drive. Designed for the application of extreme speed and centrifugal force to laboratory prob- lems. Operating speed of 25,000 revolutions per minute produces a separating force over 15,000 times as great as gravity. In addition to maximum speed and separating force it has the fur- ther advantage of handling liquids continuously. By means of this centrifuge colloidal particles may be separated from liquids; bacteria and im- purities may be removed from hot agar solutions; calcium soaps from wool fat, and oil soap and fatty acids from gelatine; water from fusel oil; suspended matter from lacquers, acids, glue, etc.; sulphuric acid from oil; pigments from paints and varnishes, and many other determina- tions and separations made which otherwise can be effected not at all or with great difficulty. Especially valuable in the chemical laboratory for slow filtering precipitates such as ferric hydrate, ammonium phosphomolybdate, arsenic sulphide, etc., in routine analysis. CENTRAL SCIENTIFIC CO., CHICAGO. TT. 8. A. 143 2784. 2785. 2786. 2787. 2788. 2790. No. 2784. No. 2785. No. 2790. CENTRIFUGAL MACHINE, Sharpies Super-Centrifuge, Continued. The machine consists essentially of an iron frame cast in one piece. Within this is suspended a seamless tubular tin lined steel bowl, by means of a flexible spindle, with a cone at its upper end, running on ball bearings. By means of the cone bearings wear is automatically taken up. At the lower end of the bowl is a guide or drag which keeps the bowl centered and absorbs vibrations. Parts are easily removed for cleaning and can be readily and economically replaced when worn. The liquid comes in contact only with tinned surfaces except in passing through the feed nozzle, which is of nickel; consequently weak acids or alkalies may be handled continuously or stronger reagents for brief periods. If desired the machine parts may be obtained plated with gold, silver, or platinum, at an additional charge. Height of machine, 24 inches. Size of base, 10^x8 inches. Weight, 50 pounds. Maximum speed of gear driven machine, Diameter of inner bowl, 2 inches. 25,000 r. p. m. Capacity of bowl, 250 cc. Power required to operate, % h. "p. Complete with tin lined bowl, geared crank and pulley, 2x10 inches, for hand or belt drive $125.00 CENTRIFUGAL MACHINE, Sharpies, same as No. 2782, but with turbine wheel attached to shaft for driving with steam or compressed air at 20 pounds pressure. With a pressure of 25 pounds, a maximum speed of 40,000 r. p. m. is attained, producing a centrifugal force of over 40,000 times gravity. Air consumption, 40 cubic feet per minute; steam consumption, 60 pounds of water per hour. Complete with speed indicator 125.00 Extra Inner Bowl, of steel nickel-plated, for use in clarifying or filtering liquids in quantities not exceeding 50 cc. It is not continuous in action. Consists of two parts, threaded to screw together. Liquid is placed in lower part, the top screwed on, the whole bowl is then placed within the regular super-centrifuge bowl. When the bowl revolves, the liquid is instantly drawn into the upper chamber, where the solids are packed against the outer-wall. The liquid again collects in the lower part when the machine is stopped, leaving a perfectly clear filtrate. Quantitative results may be secured with proper care. Especially valuable in handling serums and bouillons in bacteriological work 8.00 Extra Inner Bowl, same as No. 2785, but silver-plated 12.00 Extra Inner Bowl, same as No. 2785, but gold-plated 15.00 Extra Inner Bowl, same as No. 2785, but platinum-plated Price quoted upon application. CENTRIFUGE TUBE BALANCE, for use in selecting glass centrifugf tubes whose weights are approximately equal, in order to prevent centrifuge bearings from wearing unevenly. It will take either 15 ce or 50 cc standard tubes. Finished in black enamel and nickel-plate. Complete with two aluminum shields and two 15 cc plain glass tubes, mounted on enameled iron base with robber feet 18.00 144 CENTEAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. AX\BLE OFTHE CHEMICAL EEMENTSWmi THEIR ATOMIC WIGHTS COMPILED BY DR. F W.CLARKE AND REPORTED TO THE AMERICAN CHEMICAL SOCIETY AJ 771 Helium He. 4.0 Hndiun Rh. IOZ.9 AnUmorwstibtumi Arton 5b. 120.Z A. 39.9 Hydrogen H. 1.008 Ruhidium Rb. B5.4S Em I — Jn. 114.8 Rulhpnium Ru. 1017 Anemc. As. 75.0 lidine L 1239? Sjmarium Scindium _Sl. 1504 St. 44.1 Barium Hi '137 37 Iridium Ir 1931 Bismuth Bi 2D80 kraiLinmiM. — ft. 55.85 Kryplnn Kr. 818 StlMium S« 79 7 EM B 11.0 Silirnn Si. 28.3 Bromine h 7932 lunthannm Ir 139.0 Silver. 'Argintum). SodiUm.(Hatrliim) Slrenliiin __At 10788 III 23.00 Sr. 87.62 Cadmium. Cd. IK4D Itad.ipiumbiiiw Pb. 287.10 Lithium ti. 700 r«f»inm Cs. 13281 Calcium Ca. 40.09 luliriiim III 174 D Sulphur S. 32.07 Carbon C 1200 Kionesmn H( 2432 Tanblum la. 181.0 Ceriun Ct 14025 HanjanesB NIL 5493 Tellurium Te. 127.5 Chlorine 0 3546 Mercury 'Hyuroreyrumi Hi. 200.0 Molybdenum Na 35.0 Neodymura. Nd. K4.3 Tb. 159.2 Cr 52.1 Thallium TI. 2040 SSt Co 5837 Thtmnm Th. E32.42 Columbiunuiiom nil Cb. 93.5 Cu. 8357 Kton IB. 20.8 Thulium Tm. 168.5 Nickel IL 58.68 Tin.iSlinnuml Titanium Sn. 113.0 Ti. 48.1 Dy 162.5 Kitroien It 14.01 Frhium Er. 167.4 Osmium OS. 190.9 Tun8sltn.n«iiiirnimiiiini. Uranium W. 184.0 _J. 238.5 EuropiUB Ell 152.0 Oiy»M D IE.OO Fluorine F 19.0 Mladim Pi 106.7 Platinum. ' PL 195.0 Vanadium. V. 51.2 Gadminium Gallium Ed. 157.3 Ca 69.3 X(?nnn, IB. 128.0 Ytterbium. »«iytitii».!_rb. I7Z.O YHrium T 890 Germanium Glucinum. Btniim Cold. Aimiro COffK 8e. 725 M El 91 Potasiiom.iuttiM) R. 3ilO PraseoeVmium Pr. 148.6 7inc Zn. 65.37 ___Au. I37.Z itscm/nncto Rjjium «i 2214 Zirconium. Zr 90.6 durxicra w na. usonutxrtPHimrt/s No. 2804. 2800. CHAMOIS SKIN, for cleaning instruments, etc. No Size, inches Each . A 6x8 $0.15 B 9x11 .30 C 10x13 .45 D 14x18 1.10 1478. CHARCOAL STICKS, natural willow wood, 4xlx% inches Per dozen .50 2804. CHART, Atomic Weight. Compiled by Dr. F. W. Clarke and reported to the American Chemical Society. Corected up to 1918. Size 42x62 inches. Mounted on linen back on common rollers 2.50 PERIODIC CLASSIFICATION OF THE ELEMENTS ACCORDIXO TO MENDKLEJ EFF ON BASIS out REVISED AND CORRECTED TO 191ft BY DR. F.W.CLARKE. Series Group 0 Group 1 Group Z Group 3 Group 4 Group 5 Group G Group 7 Group B 1 H-l Z Ht-4 U-7 GI-9.1 Bll C-IZ N-14 0-16 F-19 3 Nc-20 Ha- 23 MfZ44 AI-Z7I Si-28.4 P-31 S-32 CI-35« Fc-553 4 A-393 K-39.1 Ca.40l Sc-44J Ti-4ai V-SL2 Cr-5ZI Mn-bS Hi-58.7 C«-59. 5 Cu G3B Zn-654 Ea-70 Ge-7U As-75 S«-79.2 Br-7995 Ru-101.7 6 Kr=8l8 Rb-855 Sr-87.6 Y-89. Zr-90B Cb-94. Mo-96 "• Rh-103 Pd-ioas 7 Aj-10793 Cd 112.4 In 115 Sn-119 Sb-IZ0.2 Te-IZTG I-I2B37 8 XHZ8 Cs=l32.9 Ba-1374 La^l389 Ce-l4DZ5 1 Os-191 10 Ta-131. W-184 lr-193 PH94.8 II AiiH972 H8=cuQ Tl= 234.1 Pb-2QG3 Bi'208 IZ Ra-225 Th-Z3Z5 . U ZJ8.5 amau.sannricca ""' LABOKa^r^iKfri/s No. 2806. 2800. CHART, Mendelejeff Periodic System. The periodic arrangement of the elements according to Mendelejeff, on the basis of O=16, Eevised and corrected up to 1918 by Dr. F. W. Clarke. American nomenclature. Size 42x62 inches. Mounted on linen back on common rollers. 2.50 CHARTS, for Botany, Zoology and Physiography, C3nd for special bulletin. CENTRAL SCIENTIFIC CO., CHICAGO. TJ. S. A. 145 f l.\Ti:UNATIO\ \l. MIITKK STKM No. 2807. 2807. CHART, Metric, showing in full size and in perspective where necessary the nnits of the interna- tional metric system, with units of the English system for comparison. Tables showing the de- rivation of the names of the metric units and their abbreviations, together with tables of metric and English equivalents are included. The chart is 25 by 41 inches, mounted on cloth back, with common rollers i $2.00 2808. CHART, Spectrum, showing 6 spectrum and 12 intermediate colors with two tints and two shades of each. A chart of approximately complementary colors, one showing the relative value of spectrum colors as obtained by a prism, and a set of grays, showing eight tones are included. 2.M 2812. CHART, Spectrum, mounted on linen back with common rollers and containing the following spectra (size of each spectrum 5.5 cm wide, 52 cm long) : K, Rb, Cs, Tl, Na, Li, Ca, Sr, Ba. 5.50 2814. CHART, Spectrum, same as No. 2812, with the following spectra: In, C, Bo, Mn, Pb, Cu, Co, Ni, Fe 5.50 No. 2824. No. 2818. No. 2820. No. 2830 No. 2828. 2816. 2818. 2820. 2822. 2824. CHEESE-CLOTH Per yard CHIMNEYS, Students' Lamp Per dozen CHIMNEYS, Argand, straight, 2x7 inches Per dozen CLAY PIPES, see Pipes, Clay. CLOTH, Emery, see Emery Cloth. CHISEL, Cold, length 6 inches, width of blade %-inch CHISELS, Gouge, cast steel, with wood handle. "Width of blade, inches Total length, inches Each 2826. CHISELS, Plain, cast steel, with wood handle. No Width of blade, inches Total length, inches Each . 13 90 13 .80 .12 1.80 1.20 .18 B 1 14 1.10 B 1 14 1.10 2828. 2830. CHLORINE ABSORPTION APPARATUS, Bnnsen-Fresenius, with flask ground on ...... 1.40 CHLORINE TUBE, 2x100 cm, for showing decomposition of water by chlorine ............ 80 146 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 2864. No. 2862. CLAMPS, ALL KINDS 2838. CLAMPS, Beaker, Cliaddock's. No A B For beakers, ce 75 to 250 250 to 550 Each $0.20 .20 2840. CLAMP, Burette, of stamped steel with rounded jaws; has check nut to adjust to any position, and clamp holder. An excellent clamp for general use $0.40 2842. CLAMP, Burette, same as No. 2840, but with jaws rubber covered 45 2844. CLAMP, Burette, same as No. 2840, but made entirely of brass 80 2846. CLAMP, Burette, same as No. 2844, but with jaws rubber covered 85 2848. CLAMP, Burette, of japanned iron, with coiled spring enabling burette to be adjusted easily and quickly. With rubber covered jaws .60 2850. CLAMP, Burette, or tube, of brass nickel-plated, for screwing into wall or shelf. Open in front leaving graduations uncovered for reading 40 2852. CLAMP, Burette, Bunsen, of stamped steel with rounded jaws, for use with clamp holder No. 2914; for tubes, burettes, etc. Width of opening, 2 inches; total length, 9 inches; diameter of rod, % inches i 30 2854. CLAMPS, Burette, Bunsen, same as No. 2852, but with rubber covered jaws .35 2856. CLAMP, Burette, double, same as No. 2848, for two burettes 70 2858. CLAMP, Burette, double, of brass, jaws cork lined 3.00 2860. CLAMP, Burette, Hofmann's, double 36 2862. CLAMP, Burette, double, designed by Prof. Lincoln of the University of Illinois. Burettes are held perpendicular and are easily removed. A very convenient and rigid clamp, nicely made. 1.10 2864. CLAMP, Condenser, new form, with V shaped jaws of stamped steel, enabling very small tubes to be clamped. For clamping thermometers, burettes, condensers, etc. For tubes up to 2% inches; total length, 11 inches; diameter of rod, % inch .50 2865. CLAMP, Condenser, same as No. 2864, but with rod 12 inches long. Total length, 17 inches. .60 F151. CLAMP, Condenser, same as No. 2864, but with nickel-plated rod 12 inches long 70 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 147 No. 2872. No. 2888. 2868. 2870. 2872. 2874. 2876. 2878. 2880. 2882. 2884. 2886. 2888. CLAMP, Condenser, same as No. 2864, with check nut to adjust to any position, and with clamp holder attached $°-90 CLAMP, Dish, Stoddard's, of brass, white-plated, for holding evaporating and other dishes up to 4% inches in diameter -16 CLAMP, Flask, for flasks and large tubes, of wood, with wire spring. Length, 10^ inches. .60 CLAMP, Test Tube, of wood, improved form with brass spring 12 CLAMP, Test Tube, of spring wire, nickel-plated, with improved finger rests. Length, 6^ inches 16 CLAMP, Test Tube, Chaddock's, of japanned wire, shaped as shown in illustration 20 CLAMP, Test Tube, Stoddard's, of spring wire. Length, 4% inches. (See No. 2918 Clamp Holder.) 10 CLAMPS, Tubing, Cut-off, of brass, nickel-plated. No A B For tubing up to. inches ^6 %6 Each Per dozen -55 .90 CLAMPS, Tubing, Mohr's Pinchcock, of brass spring wire, nickel-plated. No A B C Total length, inches 2% 3 3% For tubing up to, inches r'i,; % % Each 10 .12 .16 CLAMP, Tubing, Mohr's Pinchcock, of rectangular wire, giving a flat bearing surface on the tub- ing 3 mm wide, insuring close contact and safe guarding the tubing. Made of stiff spring brass white-plated, with flat finger grips. Length, 2% inches; for tubing up to % inch 20 CLAMPS, Tubing, Spring Pinchcock, Day's, Patented. Can be placed on or removed from rubber tubing without disconnecting apparatus. The most serviceable pinchcock made. Constructed of strong brass spring wire, white-plated. No A Length, inches 2% 2% For tubing up to, inches 91 6 % Each . 08 .09 148 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 2890. No. 2890 (open). No. 2902. No. 2906. 2890. CLAMPS, Tubing, Screw Compressor, new form, of brass nickel-plated; a combination of Hof- mann's and the old form; can be placed upon rubber tubing without disconnecting apparatus. No A B For tubing up to, inches %e % Each $0.20 .25 2892. CLAMP, same as No. 2890, but extra heavy, for pressure tubing up to % inch inside diameter. 35 2894. CLAMP, Tubing, Bunsen's Screw Compressor, of brass, nickel-plated, for heavy rubber tubing. Size, % by 1% inches 40 2896. CLAMPS, Tubing, Hofmann's improved form, nickel-plated -with open jaw. No A B For tubing up to, inches ]/2 % Each 22 .28 2898. CLAMPS, Universal, with swivel jaws adapting themselves to irregular shapes; with check nut enabling object to be held at any angle. For use with Clamp Holder No. 2914. No A B For tubes up to, inches 3 Total length, inches 8 10 Each 65 .85 2900. CLAMPS, Universal, same as No. 2808, with iaws rubber covered. No A B Each 70 .90 2902. CLAMP, Watch Glass, of brass, nickel-plated, for watch glasses up to 2% inches in diameter .12 2904. CLAMP, Watch Glass, of brass spring wire, for watch glasses up to 3 inches in diameter. . . .10 2906. CLAMP, with brass hook for supporting thermometers and other apparatus; with screw for at- taching to support rods 75 2914. CLAMP HOLDER, of iron with brass screws, for fastening clamps to support rods up to %0 inch in diameter .35 2916. CLAMP HOLDER, same as No. 2914, with swivel, for attaching clamps at any angle 50 2918. CLAMP HOLDER, Stoddard's, an ingenious device for rigidly holding Stoddard Wire Test Tuba Holder No. 2880 in any position. Provides for vertical and horizontal adjustment to any angle, uid will adapt itself to a great many uses in the laboratory. Clamp holder with right angle clamp, but without Test Tube Holde'r No. 2880 • 44 2919. CLAMP HOLDER only of No. 2918 16 2920. RIGHT ANGLE CLAMP only of No. 2918. Has one %2-inch hole and one %-ineh hole. .. .28 2922. BASE AND ROD for use with No. 2918 as shown in illustration. Base is heavy, and stable even with excessive load; rod is 15x%2 inches -60 CENTRAL SCIENTIFIC CO., CHICAGO. TJ. 8. A. 149 No. 2940. No. F157. No. F213. No. F211. No. F153 (in use). CLAMPS, GENERAL LABORATORY The clamps listed in this section differ from the usual chemical laboratory clamps in that they are carefully machined to secure perfect alignment of apparatus with which they are used. All V's are accurately milled, holes are carefully reamed and faces are smoothly planed. They should be selected whenever it is essential to have apparatus assembled with an accurate arrangement of parts. 2930. CLAMPS, Adjustable, steel. These clamps are so constructed that they can be quickly adjusted and will lock themselves the moment the pressure is applied to the screw. The bar is 3% inches from the center of screw. A very desirable clamp for light or medium work. No B C Maximum opening, inches 6 10 18 Each $1.10 1.30 L80 F211. COLLARS, with set screw, allowing a clamped rod to rotate freely, and at the same time prevent- ing motion along the axis. The two smaller sizes are of brass, nickel-plated; the others of iron, neatly japanned. No A B C For rods' of diameter, mm 10 13 19 30 Each $0.40 .50 .60 .80 F213. HOOK COLLARS, with set screw, of substantial construction. The many uses to which such a piece may be put will readily be seen. The two smaller sizes are of brass, nickel-plated and the other of cast iron, neatlv japanned. No ." A B C For rods of diameter, mm 10 13 19 Each 60 .70 .80 F153. CLAMPS, Extension, for holding two rods parallel to each other. (The illustration shows the clamp in use with two rods and an iron table top.) No A B C For rods of diameter, mm 10 13 19 Each . .50 .70 1.00 2940. CLAMPS, Hand Screw, wood, with saw cut threads on screws. No A B C D E Length of jaws, inches 7 10 12 Opening, inches 2 3 4V> 5% Each 55 .65 .80 1.00 1.25 F155. CLAMP, Extension, for holding two rods parallel to each other. By using this clamp it is pos- sible to fasten two rods parallel to each other without slipping the clamp over the end of the rods, as was necessary in the old form. For use with rods of from 10 to 19 mm diameter. $0.70 F157. CLAMPS, Extension, for holding two rods in line. The lower end is reamed to fit the top of the lower rod and is provided with a set screw; upper end is tapped to receive the upper rod. No A B C D For lower rod of diameter, mm 13 19 13 19 For upper rod of diameter, mm 13 19 10 13 Size of thread of upper rod %-16 V-12 1,4 -20 %-16 Each .55 .65 .55 .65 150 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. F163 No. F171. No. F165. No. F173A. No. 2974. F163. CLAMP, Meter Stick. A convenient device for holding the ordinary meter stick in position on a rod, with V opening for clamping it to any rod from 10 to 19 mm in diameter. The meter stick is held firmly in place parallel to the rod by a thumb screw $0.55 F165. CLAMPS, Parallel-Jawed, of brass, nickel-plated, for holding square objects, mirrors, scales, screens, etc. Maximum opening of jaw, 4 cm. Bod 10 mm in diameter. No A B Eod, length, cm 10 20 Each 1.70 1.80 F171. CLAMP, Bight Angle, of brass, nickel-plated. To hold two 10 mm rods accurately at right angles to each other 50 F173. CLAMP, Bight Angle, of iron, neatly japanned. Size B and C have zero indicator for optical bench accessories. No A B C D V opening for rods of diameter, mm 13 19 19 30 Hole for rods of diameter, mm 10 13 6 19 Each 50 .60 .60 1.00 F175. CLAMP, Bight Angle, of iron, neatly japanned, with two V openings at right angles. No A B V openings for rods of diameter, mm 13 19 Each 50 .60 Note: — For less expensive right angle clamps, see No. 2914 Clamp Holder. F177. CLAMP, Bight Angle. One 19 mm V opening. Tapped ^4 -20 to receive 10 mm rod 60 F179. CLAMP, Right Angle, for lens holders, telescope supports, pulleys, etc., with zero indicator for photometer and optical bench accessories. Carefully made so that the rod will be held perpen- dicular to the V. The V opening is for rods 19 mm in diameter. No A B Hole for rods of diameter, mm 10 13 Each 60 .90 F180. CLAMP, Bight Angle, same as No. F179A, with addition of a spring so that it can be moved along the rod without loosening the set screw. Convenient for carrying photometer box. 1.50 2974. CLAMPS, Standard, made of malleable iron, and provided with ball and socket swivel cap on screw. No A B C Opening, inches 3 4 6 Each 70 .85 1.30 CENTRAL SCIENTIFIC CO., CHICAGO. U. 6. A. 151 No. F187. No. F201. F183. CLAMP, Support, Bridge Form.. For use with double rod optical bench or photometer, made up of Xo. F303 End Supports and a pair of 19 mm square rods. Is easily clamped to the rod by a slight movement of the handle seen in the illustration. Provided with an index line or zero indicator in the same plane with the vertical hole, which is 10 mm in diameter $3.00 F185. CLAMP, Support, Screw Adjustment For same uses as No. F179 Right Angle Clamp, but de- signed to give a very fine adjustment in a plane perpendicular to the V. Provided with zero indicator. Range of adjusting screw, over 25 mm, V opening 19 mm, hole 10 mm 6.00 F187. CLAMP, Swivel. Very useful for holding pulleys, mirrors and lens supports where different angular directions are desired. Two 19 mm V openings, which can be clamped at any angle to each other in parallel planes 1.20 For less expensive CLAMP, with swivel, see No. 2916 Clamp Holder. F189. CLAMPS, T, for holding two round rods at right angles to each other in the same plane. No A B For rods of diameter, mm 13 19 Each 65 1.10 F191. CLAMP, Table, of iron, for a table top 8 cm thick or less, with accurately milled Vs at right angles to each other. To be attached to the edge of the table for holding 10 to 19 mm round or square rods, either horizontally or vertically. The broad flange is carefully milled and in- sures stability. The T-screw is swiveled for protection of the table 1.60 F192. CLAMP, Table, same as No. F191. For a table 11 cm thick or less 1.80 F195. CLAMP, Table, wooden jaws, for a table top 8.5 cm thick or less. Designed for use where there is danger of injury to the table top. Upper jaw, 8x18 cm; lower jaw, 8x10 em. The large surface of jaws gives increased stability. The lower jaw is swiveled. Tapped %-12 to receive 19 mm rod 2.25 F197. CLAMP, Table. Similar to No. F195, but without the wooden jaws. The flange at the top is broad so that injury to the table top is prevented. Tapped %-16 to receive 13 mm rod 75 F245. CLAMP, Telescope, for telescopes, lenses and cylinders of any form and size as well as irregular objects up to 8 cm in diameter. Mounted on nickel-plated rod 20 cm long by 13 mm in diameter 3.00 F201. CLAMP, Telescope. Made of brass, for holding telescopes from 2 to 5 cm in diameter. The teles- cope is held in place by a leather strap and is therefore not liable to injury as is the case when metal clamps are used. A No. F133 Support Rod, 20 cm in length, is included, which may be placed either as shown in the illustration or in a position at right angles to this. The clamp is also tapped to receive a No. F131 Support Rod for carrying a scale 3.50 152 CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. F203. No. 3000. No. 3002. No. 3004. CLAMP, Stone's Tension, modified form, for use in experiments where it is desired to maintain a strain on a wire or cord and enable an individual operator to readily adjust the tension with- out the co-operation of a second person. This clamp is substantially made of cast iron and neatly finished. Will fit any table or board 7 centimeters thick or less. Wires, cords, etc., are securely clamped by an eccentric lever, as shown in the illustration $0.50 2990. CLIPS, Spring, of wood, for holding tubes, etc per dozen .20 3000. CLOCK, Interval. Alarm may be set to ring at the expiration of any interval from a quarter of a minute up to two hours. Does not start until the alarm is wound, and stops with the ring- ing of the alarm. Valuable in all experiments in which action for a definite length of time is necessary, as the operator is free to go on with other duties without fear of overrunning the time. Many uses of this timer will readily present themselves. Well made and reliable. $4.00 For TIME SWITCH for use with No. 3000, see No. 13810. 3002. CLOCK, Laboratory. This is the best clock we can furnish, adapted to the needs of the average laboratory. It is an eight-day Waltham movement, weight-driven clock, and we guarantee it to be a reliable timekeeper. The dial is 12 inches in diameter with seconds divisions. It is provided with hour and minute hands and a full sweep seconds hand for timing laboratory experiments. The pendulum is full seconds length, and provided with an adjustable platinum contact and a mercury well of improved construction, adjustable from the outside of the case, is mounted in correct position. The clock is completely enclosed in a polished oak case, with glass front and glass covered open- ing in the sides opposite the works, and binding posts on the outside for attaching battery and sounder 150.00 3004. CLOCK, Laboratory. An eight-day clock with good movement, driven by two weights. The dial is 12 inches in diameter and the pendulum beats seconds. The clock is provided with mer- cury contact adjustable from the outside of the case, and with binding posts for electrical con- nections. Complete in polished oak case with glass door 55.00 3006. CLOTH, Tracing, thin, good quality. Width, inches Per yard 30 .90 36 1.00 38 1.25 42 1.75 3008. CLOTH, Cotton, Turkey Bed, used to show bleaching effect of chlorine per yard .25 CENTRAL, SCIENTIFIC CO., CHICAGO. U. 8. A. 153 f No. 3010. No. 3014. No. 3016. No. 3018. No. 3020. No. 3022. No. 3024. No. 3026. COLOR COMPARISON TUBES 3010. COLOR COMPARING CYLINDERS, Helmet, for the estimation of iron in -water, consisting of *wo graduated tubes of the same size and graduation, with stop-cocks and metal feet.. per pair $6.00 3014. COLOR COMPARISON TUBES, Camp, graduated for manganese determination in steel. Larger tube has glass stopper ground in per set 6.00 COLOR COMPARISON TUBES, Eggertz, for the estimation of carbon and manganese in steel by the colorimetric method. No A B C Capacity, cc 30 50 100 Graduated in, cc Mo Mo M> 3016. Per set of two 3.00 3.60 5.00 3017. Per set of four 6.00 7.20 10.00 COLOR COMPARISON TUBES, Eggertz, same as No. 3016, but with ground in glass stopper. No A B C Capacity, cc 30 50 100 Graduated in, ec Mo Mo M; 3018. Per set of two 3.90 4.50 5.90 3019. Per set of four 7.80 9.00 11.80 COLOR COMPARISON TUBES, Julian's, same as No. 3016, but with bent ends to permit mixing of contents without using a stopper. The lower portion of the tube is ungraduated. No A B C Graduated from, cc 5 to 30 10 to 50 10 to 70 Graduated in, ec Mo Vio % 3020. Per set of two 3.30 4.20 4.80 3021. Per set of four 6.60 8.40 9.60 COLOR COMPARISON TUBES, Julian's, same as No. 3020, but with funnel tops to facilitate pouring in the sample. No A B C Graduated from, cc 5 to 30 10 to 50 10 to 70 Graduated in, cc Mo Mo % 3022. Per set of two 3.50 4.40 5.00 3023. Per set of four 7.00 8.80 10.00 3024. COLOR COMPARISON TUBES, Nessler, usual form for ammonia test, of clear colorless glass with polished bottoms. No A B C Graduated at, ee 50 100 50 & 100 Each 65 .80 .90 COLOR COMPARISON TUBES, Nessler, American Public Health Association Standard. Tall form of clear glass with polished bottoms. Graduations agree within 6 mm and are about 210 mm on 50 cc tube and 325 mm on the 100 cc tube from the bottom. (See Standard Methods of Water Analysis for 1915, pages 16 and 18.) In sets to agree. No A B C Graduated at, ce 50 100 50 & 100 3026. Each .85 1.30 1.60 3027. Per set of six 5.80 8.60 10.55 3028. Per set of twelve 12.00 18.00 22.50 154 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 3029. 3030. 3032. 3040. 3041. 3042. 3044. No. 3030. No. 3040. No. 3032. No. 3044. 3045. 3046. STAND for Nessler Tubes, of wood stained black, with base covered with milk glass plate. For twelve tall form 50 cc tubes. Without tubes $5.00 CAMERA for use with color comparison tubes. Improved form, so constructed that the shadow of the edge of the box cannot be thrown on the tubes; with blue and ground glass 12.00 COLOR TUBE, of brass, 24 inches long, 2% inches in diameter, closed at end by polished plate glass, held in place by a screw cap. Easily cleaned 12.00 COLORIMETERS COLORIMETER, Campbell-Hurley, for use in determining carbon in steel, for water and urine analysis, and in general colorimetric work. The telescope attachment furnishes a circular field divided vertically, rendering comparisons rapid and exact. The color of the standard solution is controlled by raising and lowering a glass plunger in a reservoir attached to one tube. Com- plete as illustrated with standard cylinder graduated to 100 cc in 1 cc divisions, and with cylin- der for unknown graduated to 100 cc in 10 ce divisions. (See Journal of the American Chemical Society, Vol. XXXIV, No. 7, for July 1912) 20.00 GRADUATED CYLINDER only for No. 3040, for unknown solution 1.25 GRADUATED CYLINDER only for No. 3040, with attached reservoir and glass plunger, for standard solution 4.00 COLORIMETER, Duboscq, the standard instrument for the determination of nitrogen, urea, ammonia, creatine, and ereatinine in blood and urine according to the methods of Dr. Otto Folin. Also used for a variety of other determinations in physiological and analytical chemistry. Will yield results accurate to within one per cent. Height of glass cylinders, 10 em , '. 120.00 Accessories for No. 3044. GLASS CYLINDER, 10 cm high 3.50 Glass Plunger, 10 cm high 7.50 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 155 No. 3050. No. 3050A, 3050. COLORIMETER, Hess-Ives Tint Photometer, for comparing different shades and hues of light colored materials or liquids with each other and with fixed standards. The instrument is used like a telescope, presenting to the eye a circular field with vertical hairline central division, one side of which is filled with light passing through a slit directly from a standard white magnesia block, while the other is filled with light passing through a slit from the sample whose color is to be evaluated. The slits are adjustable in width, and are provided with graduated scales from which a direct comparison of the degree of whiteness of two samples may be read. The light coming from the slits is thoroughly mixed and spread across the half fields by means of a patented revolving optical mixing wheel inserted between the slits and the field lens. Comparisons of colors may be made just as readily by making successive measurements through three color screens, pure red, green and blue-violet. The instrument eliminates entirely the per- sonal equation and offers a fixed standard of color measurements which may readily be reproduced. This instrument is especially adapted for use with oils, paper, flour, sugar, soaps, pigments, etc. Complete as described with motor for operating optical mixing wheel, on adjustable supports $175.00 3050A. CABINET for Xo. 3050, constructed of hardwood, nicely finished and provided with drawers and cabinets for the storage of accessories. This cabinet provides a convenient and portable dark room for color measurements 60.00 3051. DAYLIGHT LAMPS for use with Xo. 3050, providing a definite and constant illumination. No A B For volts 110 220 Each . 20.00 20.00 156 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 9 10 « No. 3048. 3048. COLORIMETER, Dunning, for estimating the quantity of phenol-sulphone-phthalcin excreted when applying the Rowntree-Gerahty renal functional test. Complete with colorimeter box, empty ampoule, and 13 calibrated test ampoules varying in color, in polished wooden box, 2%x3:%x5 inches. (See Journal of Pharmacology and Experimental Therapeutics, Vol. I, No. 6, for July 1910, page 579; also the Journal of the American Medical Association, Vol. LVII, No. 10, page 811) $6.00 PHENOL-SULPHONE-PHTHALEIN AMPOULES, for use with No. 3048, containing sterile, bio- logically standardized solution of the mono-sodium salt, of strength 6 mg to each cc; in box of 10 ampoules per box 1.00 3049. 3052. COLORIMETER, Kuttner's Micro, for directly estimating haemoglobin and sugar in the blood; uric acid, creatine, and creatinine in blood and urine; and for determining the renal function according to the method of Rowntree and Gerahty. The instrument consists of a closed upright box 2.5x2.5x8.5 cm, with openings for the graduated and the standard color tubes. The tubes are viewed through a window in the front provided with a Helmholtz double plate, which shows the colors in a continuous band, rendering the comparison very exact. A sliding door forms the front of the box and affords protection to the prism. The size of the outfit enables it to be carried in the pocket. Complete with housing of hard rubber with Helmholtz double prism and sliding door; one each pipettes 25 cmm, 0.1 cc, 0.2 cc, and 2 cc; two graduated 10 cc test tubes; one transfer pipette; graduated solution tube holding 140 cmm; and pocket carrying case with sufficient space for several standard color tubes. (See Journal of the American Medical Association July 17, 1915, pages 245 and 246; and April 29, 1916, pages 1370-1373) 18.00 Extra Parts for Kuttner Micro-Colorimeter. 3053. Colorimeter Housing, of hard rubber, with prism 8.00 3054. Pipette, graduated to 25 cmm 1.00 3055. Pipette, 0.1 cc, graduated in 0.01 cc 1.00 3056. Pipette, 0.2 cc, graduated in 0.02 ec 1.00 3057. Pipette, 2 cc, graduated in 0.2 cc 1.00 3058. Pipette, Transfer 20 3059. Test Tube, graduated to 10 cc .90 3060. Tube, Solution, for diluting unknown to match standard color, graduated to 140 cmm 1.50 3061. Pocket Carrying Case, with space for several standard color tubes 2.50 REAGENTS FOR KUTTNER MICRO-COLORIMETER. In glass stoppered bottlea 1 oz. 2 oz. 4 oz. Acid, Acetic, 1% solution for determining uric acid in blood .25 .40 Acid, Hydrochloric, normal solution for determining creatine in urine. ... .25 .40 Acid, Hydrochloric, ],{0 normal solution for determining haemoglobin. ... .20 .35 Acid, Picric, C. P., saturated solution for determining sugar in blood, creatine and creatinine in urine, and ereatinine in blood .50 1.00 Acid, Uric Reagent, for determining uric acid in renal calculi, urine, blood 90 Colloidal Iron, 5% solution for determining uric acid in blood and urine, and creatinine in blood .30 .50 Phenol-Sulphone-Phthalein, in sterile ampoules per box of 10 1.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 157 No. 3080. REAGENTS FOR MICRO-COLORIMETER, Continued. In glass stoppered bottles 1 oz. 2 oz. 4 oz. Sodium Acetate, C. P., saturated solution for determining uric acid in blood .. ... 25 .40 Sodium Carbonate, saturated solution for determining uric acid in renal calculi, urine, blood .25 .40 Sodium Carbonate, 10% solution for determining sugar in blood .20 .35 Sodium Fluoride, 2% solution for determining sugar in blood 40 Sodium Hydroxide, 10% solution for determining creatinine and crea- tine in urine, creatinine in blood, and uric acid in renal calculi .30 .50 STANDARD COLOR SOLUTION TUBES FOR USE WITH KUTTNER MICRO-COLORIMETER. TESTED AND APPROVED BY DR. KUTTNER. 3068. Haemoglobin Test Standard Tube, equivalent to 15 grams haemoglobin or 20 cc oxygen (Oo) 2.00 3069. Carbonyl Haemoglobin Standard Tube, equivalent to 20% oxygen (O2) 5.00 3070. Sugar Test Standard Tubes, a set of two, A and B, the former being equivalent to 0.1 per cent, of sugar, the latter having twice that concentration. Xo A B Per tube 1.00 1.00 3071. Phenol-Sulphone-Phthalein Test Standard Tubes, a set of three, the No. 1 tube reading directly in percentage, the Xos. 2 and 3 tubes being weaker in the proportions 2 and 4. Xo 1 2 3 Per tube 1.00 LOO 1.00 3072. Uric Acid Test Standard Tubes for determining uric acid in blood, a set of two, A and B, the former being equivalent to 0.01 mg and the latter to 0.005 mg. Xo A B Per tube 1,00 1.00 3073. Uric Acid Test Standard Tube for determining uric acid in nrine and stone, equivalent to 0.02 mg L50 3074. Creatine and Creatinine Test Standard Tubes for nrine, a set of two, A and B, the former equivalent to 0.01 mg, the latter to 0.02 mg. Xo A B Per tube LOO 1.00 3075. Creatinine Test Standard Tubes for blood, a set of two, A and B, the former equivalent to 0.01 mg, the latter to 0.02 mg. Xo A B Per tube LOO 1.00 3080. COLORIMETER, Myers, a simple and inexpensive outfit for clinical purposes, consisting of a box containing two tubes 26x1.2 cm graduated from 5 to 25 cc. Comparison of colors is made in the nngraduated part through an opening 2.2x1 cm against a white glass background. The un- known is diluted by the addition of water from the diluting pipette, until the colors match. Calculations are very simple. Complete with housing, filling pipette with rubber bulb, holder for pipette and two graduated tubes, in card-board box with directions for use. (See the Journal of Laboratory and Clinical Medicine, VoL I, No. 10, for July 1916, page 760) 8.00 158 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 3082. No. 3088. No. 3089. 3082. COLORIMETER, Kober Nephelometer, for use in accurate colorimetric and nephelometrie deter- minations in chemical and biological work, with any depth of liquid up to 110 mm. The opti- cal parts are arranged to give a Lummer-Brodhun field, with the light from one side forming a square area enclosed by the circular area of light from the other side. The plungers are made of opaque black tubing with glass ends fused on, as are also the glass cups for colori- metrie uses. The cups for nephelometrie uses are made of clear glass tubing with black opaque glass bottoms fused on. The cups are raised and lowered by a screw with a double milled head, which gives the effect of a double adjustment. An accurately divided scale is provided, and the verniers are adjustable enabling the instrument to be set quickly at zero. The framework can be tilted like a microscope and securely clamped in any position. The source of light for nephelometrie work is a concentrated filament lamp in front of which is mounted a condensing lens to bend the rays of light parallel. The reflecting mirrors are in pairs so that any inequalities in the light falling on the two sides of the instrument may bo corrected. The entire instrument is enclosed in a metal housing which effectually cuts out any stray light and protects the parts from dust. Complete with 2 long and 2 short Colori- metric Cups No. 3090, 2 long and 2 short Nephelometrie Cups No. 3091, Lamp-house with 110 volt lamp, cord and plug, mounted on a black polished board with switch; with directions for use. (See the Journal of Biological Chemistry, Vol. XXIX, No. 2, for March 1917, page 155) , $105.00 Parts and Accessories for No. 3082. 3083. Lamp-House only, without lamp 27.50 3084.- Concentrated Filament Lamp for 110 volts 2.00 3085. Zero Gage 30 3086. Plungers, of black glass with clear fused bottoms per pair 4.00 3087. Colorimetric Cups, of black tubing with blue bottoms, for use with artificial light. No A B Style long short Per pair 4.50 4.50 3088. Colorimetric Cups, of black tubing with white bottoms, for use with daylight. No '. . . . A B Style long short Per pair 4.00 4.00 3089. Colorimetric Cups, of white tubing with blue bottoms, for use with artificial light. These are adapted for uses requiring that the liquid be kept under observation by the operator. No A B Style long short Per pair 3.50 3.50 3090. Colorimetric Cups, of white tubing with white bottoms, for use with daylight. No '. . . . A B Style long short Per pair 3.00 3.00 3091. Nephelometrie Cups, of white tubing with black bottoms. No A B Style long short Per pair 4.00 4.00 3092. Portable Dark Room for use with No. 3082 . . 35.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. No. 3094. NO. 3098. Nos. 3100-4 No. 3102. 3094. COLORIMETER, Schreiner's, as used in the Laboratory of the Bureau of Soils, United States Department of Agriculture. All parts of the instrument which come in contact with the solu- tions are of glass. The Colorimeter consists essentially of two graduated glass tubes which contain the standard and the unknown colorimetric solutions, with two smaller glass immersion tubes by means of which the length of the column of liquid in the graduated tubes may be changed. These tubes are mounted on the colorimeter stand by an improved method which makes their adjustment exceedingly simple and permits a rapid and easy setting while the comparisons are being made. Complete with graduated and plain tubes. (For full description see Journal of the American Chemical Society, Volume XXVII, September 9, 1905, and Bul- letin Xo. 31, United States Department of Agriculture, Bureau of Soils) $20.00 3095. TUBES, Graduated, for No. 3094, with 100 scale divisions, 2 mm apart per pair 5.00 3096. TUBES, Immersion, for Xo. 3094, 26 cm long with polished bottoms per pair .90 3098. COLORIMETER, Ukena's Comparator, widely used in determining carbon and manganese in iron and steel by the Eggertz method. Complete with stand, ground glass plate, and 10 Eggertz carbon tubes with ground stoppers, graduated to 30 cc in i{0 cc divisions 35.00 3100. COLORIMETER, United States Geological Survey Standard Outfit, for determining color in watel analysis. The method consists in comparing the color of the water under examination with that of a series of glass disks, rated in color values according to the platinum-cobalt scale of parts of platinum per million. Colorimeter complete with 4 aluminum tubes, one with clips for holding disks, and others respectively 50, 100 and 200 mm long, for holding water to be tested; six standard disks of amber colored glass mounted in aluminum; in compact morocco covered case. (See Bulletin 151 of the United States Geological Survey) 38.50 3102. TURBIDITY SCALE, United States Geological Survey Standard, made of aluminum, 8 inches long and graduated in parts per million. To one end is attached a tape 4 feet long, similarly graduated. Into the other end is fastened a nickel-plated brass screw eye containing a piece of rolled platinum wire to be viewed. The depth of its disappearance to the eye indicates the turbidity. Complete in case. 7.50 3104. COLOR AND TURBIDITY OUTFIT, consisting of Nos. 3100 and 3102, combined in morocco cov- ered case . 45.00 160 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 3120-2. COMBUSTION APPARATUS 3120. COMBUSTION APPARATUS, C. M. Johnson's, for the determination of carbon in iron, steel, ferro- alloys, etc. With this outfit a single combustion can be completed in 25 minutes. Complete as illustrated with Hoskins Electric Combustion Furnace, mer- cury pressure gage, drying jar for solid absorbents, ( safety jar for potassium hydroxide solution, calcium ' chloride and soda lime jars, mercury valve, fused silica combustion tube, jar for granular zinc, jar for phosphorus pentoxide, absorption tube for carbon dioxide, and connections. (See "Rapid Methods for the Chemical Analysis of Special Steels, Steel Mak- ing Alloys, and Graphite," by C. M. Johnson.) No. No A B h With furnace and rheostat for, volts 110 220 Each $50.00 50.00 3122. COMBUSTION APPARATUS, C. M. Johnson's, same as No. 3120, but with Multiple Unit Elec- tric Combustion Furnace No. 6226. No A B With furnace and rheostat for, volts 110 220 Each 50.00 60.00 Parts for Johnson's Combustion Apparatus. Hoskin's Electric Combustion Furnaces. No A B For volts 110 220 6210. Furnace only 25.00 25.00 6211. Furnace with rheostat 33.50 33.50 Multiple Unit Electric Combustion Furnace, for use on either 110 or 220 volts. 6226. Furnace only 25.00 6227. Furnace with rheostat (voltage must be specified) 33.50 3186B. Combustion Tube, of opaque fused silica for Nos. 3120 and 3122, 24 inches long and % inch inside diameter i 6.00 3123. Mercury Pressure Gage, (A) to indicate leakage of joints or stoppage of flow 90 3124. Jar for Solid Absorbent, (B) such as potassium hydroxide sticks 1.50 3125. Safety Jar, (C) for potassium hydroxide solution 1.50 3126. Calcium Chloride Jar, (D) 1.50 3127. Soda Lime Jar, (E) 1.50 3128. Mercury Valve, (F) to prevent back flow 80 3129. Jar for Granular Zinc, (H) to absorb acid, lead, sulphur, and chlorine vapors 80 3130. Jar for Phosphorus Pentoxide, (I) to absorb water 60 3131. Absorption Tube, for Carbon Dioxide, (J) to be weighed for calculating percentage of carbon 1.00 Combustion Tube, Clay, C. M. Johnson's, see No. 3178. 3134. MILLING MACHINE, C. M. Johnson's, for obtaining iron and steel samples for use in combus- tion apparatus 42.00 3136. "Rapid Methods for the Chemical Analyses of Special Steels, Steel Making Alloys, and Graphite' ' by C. M. Johnson, describing No. 3120 Combustion Apparatus 3.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. 161 Nos. 3138-40. 3138. COMBUSTION APPARATUS, Vanier's, for determining carbon in iron and steel by the combus- tion method. Complete as illustrated, with Hoskins Electric Combustion Furnace with rheo- stat, two four-liter aspirator bottles, potash bulb, calcium chloride tube, fused silica combus- tion tube, zinc tube, sulphuric acid bulb, Vanier 's Combined Absorption Bulb and Drying Tube (patented), two 3%x% inch Alundum combustion boats, % Ib. of E. B. Alundum and with necessary connecting tubing, supports, clamps, glass rods, etc., but without oxygen tank. No A B With furnace for, volts 110 220 Each $62.00 62.00 3140. COMBUSTION APPARATUS, Vanier's, same as No. 3138, but with Multiple Unit Electric Com- bustion Furnace No. 6226. No A B With furnace and rheostat for, volts 110 220 Each 62.00 62.00 Parts for Vanier Combustion Apparatus. Hoskins Electric Combustion Furnaces. No A B For volts 110 220 6210. Furnace only 25.00 25.00 6211. Furnace with rheostat 33.50 33.50 Multiple Unit Electric Combustion Furnace, for use on either 110 or 220 volts. 6226. Furnace only 25.00 6227. Furnace with rheostat (voltage must be specified) 33.50 1614F. Aspirator Bottles (H), four -liter, with rubber tube outlet at bottom, for use in keeping pressure constant, the lower one being filled with water each 1.75 3141. Potash Bulb (A), for purifying oxygen before entering tube 70 2320A. Calcium Chloride Tube (B), for drying the oxygen gas 1.40 3186B. Combustion Tube (D), of Opaque Fused Silica, glazed, 24 inches long and % inch inside diameter 6.00 3143. Vanier Zinc Tube (E), to be filled with granulated zinc for removing sulphur and acid fumes 1.10 3144. Vanier Sulphuric Acid Tube (F), for absorbing moisture 1.90 124. Vanier Absorption Bulb (G), for carbon dioxide, a combined potash and drying tube, to be weighed for determining percentage of carbon in sample 10.50 No. 3152. No. 3150. 3150. COMBUSTION BOATS, of Alundum, especially adapted for the determination of carbon in iron they may be used repeatedly. With handle. 3152. and steel. Since the alundum is not affected by iron oxide Furnished in fine mixture only. Thickness of wall, ^ inch. No '. A B C D E Length, inches 3V2 3% 4^ 5 5% Width, inches V2 % % % % Depth, inches Bore, inches Hie J9i6 Diameter outside, inches % % Each 75 1.00 3164. COMBUSTION CAPSULES, of Alundum, for ashing coal, flour, etc. Will withstand high tem- perature and can be used repeatedly. Made in mixture BA 84. No A B C D ' Diameter, inches l%g 1%G 1% 1% Height, inches %e % % % Capacity, ce 10 18 25 Each 25 .30 .40 .35 3166. COMBUSTION CAPSULES, of Best American Porcelain, without lip, as recommended for the de- termination of ash in coal or coke by the Joint Committee of the American Chemical Society and the American. Society for Testing Materials. (See Journal of Industrial and Engineering Chemistry, January 1917). No A B Diameter, inches 1% 2 Depth, inches % l^ie Each 20 .20 3170. COMBUSTION CAPSULES, of Opaque Fused Silica, for ash determinations and ignitions. Depth, % inch. No A B C D Diameter, inches 1% 1% 2 2% Capacity, cc 10 15 20 35 Each 75 .76 1.13 1.25 For other CAPSULES, see No. 2408. CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 163 No. 3182. Nos. 3178, 79 and 80. 3178. COMBUSTION TUBES, Clay, Vitrified, C. M. Johnson's, for use in carbon determinations in iron and steel. (See Journal of Industrial & Engineering Chemistry, VoL V, No. 7, for July 1913, page 581.) No A B Length, inches 23% 27% Diameter inside, inches % 1^6 Diameter outside, inches lUr. 1*4 Each $4.25 5.25 3179. TAPEEED CLAY CONNECTORS, for Combustion Tubes Xo. 3178, wi^iout rubber sleeve. For tube A B Each 1.75 2.00 3180. BXTBBER SLEEVES for use with Nos. 3178 and 3179. For tube A B Each 1.75 2.00 3182. COMBUSTION TUBES, of Best American Porcelain, glazed inside and outside, 60 cm long. Thickness of wall, about 3 mm. Diameter inside, mm 15 18 25 Each 3.25 4.10 4.75 Note: — For special lengths add or subtract 1/100 of price for each em of difference from stock lengths. COMBUSTION TUBES, Opaque Fused Silica, melting point about 1500 degrees C.; unaffected by sudden changes in temperature. Length, 60 cm; thickness of wall, 2 mm. No A B C Diameter inside, mm 15 18 22 3184. Each unglazed 438 5.25 5.75 3186. Each glazed 5.63 6.00 7.00 3187. COMBUSTION TUBES, Pyrex Glass, for use in oxidation and reduction experiments, etc. No A B C Length, mm 200 300 450 Diameter inside, mm 5 10 19 Each 16 .22 .60 3188. COMBUSTION TUBES, Pyrex Glass, 100 cm long. Thickness of wall, 2 to 3 mm. Diameter inside, mm 12 18 20 25 Each 90 1.50 1.80 2.00 For COMBUSTION TUBING see No. 7206. COMBUSTION TUBES, Transparent Quartz. These tubes can be furnished in any length and with wall of three different thicknesses; thin (0.5 mm), medium (0.75 mm) and heavy (1 mm). The prices given are per 10 cm of length. Bore, mm 1 2 3 5 10 15 20 30 40 50 3190. Per 10 cm, thin wall. 42 .60 .90 1.20 1.92 2.82 3.90 5.70 9.00 12.00 3191. Per 10 cm, medium wall 60 .90 1.20 1.80 2.88 4.20 5.70 8.52 13.50 18.00 3192. Per 10 cm, heavy wall 90 1.20 1.50 2.40 3.90 5.70 7.50 11.40 18.00 24.00 No. F521. No. F523. F521. F523. COMPASS, Eagle Pencil. The most universally used school compass. Pen, pencil, divider and compass combined. Provided vrith set nut. Size 5% inches over all. Complete with extra leads Each .30 Per dozen 3.00 COMPASS, Pencil. Easily attached to a common pencil. Solid steel leg, durable and accurate. Without pencil Each .15 Per dozen 1.50 164 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. F2617. No. F2625. Metal cap needle, brass case, card dial, beveled glass; the three F2615. COMPASSES, MAGNETIC. larger sizes with ring. Diameter, mm Each F2617. COMPASS, .MAGNETIC. Agate cap needle, brass case, brass dial, 2° divisions, beveled glass, with cover. Diameter, mm 10 $0.12 16 .20 25 .40 40 .65 50 .75 40 1.80 50 2.00 Each F2619. COMPASS, MAGNETIC. Agate cap needle. A low priced but high-grade compass, with dial of enameled card graduated in 5° divisions. The needle is of special steel, heavily magnetized. The case is brass, gunmetal finish, and has a diameter of 38 mm and a thickness of 16 mm. A heavy beveled glass serves as a cover, making the whole practically dust and water-tight $0.70 F2621. COMPASS, MAGNETIC. Agate cap needle, 37 mm aluminum pointer and stop for needle. Brass case, raised metal dial with 2° divisions. Especially useful in building galvanoscopes, tangent galvanometers, etc. Diameter, 50 mm 2.50 F2623. COMPASS, MAGNETIC. Agate cap needle, brass case, raised card dial with 2° divisions, beveled glass top. Diameter, 45 mm. Similar to No. F2621, but without pointer .90 F2625. COMPASS, SIGHT, watch case form, 50 mm diameter, with raised dial and full circle divisions. Bar needle 30 mm long, with agate cap. Sights and slip cover 11.50 COMPRESSION PUMPS, see Blowers; Pumps, Air. Our Receiving Room, where New Goods are Inspected and Packed for Stock. CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 165 No. 3236. No. 3220. No. 3222. No. 3224. No. 3225. No. 3228. CONDENSERS No. 3240. 3220. CONDENSERS, Allihn's, of glass with bulb condensing tube, .with adapter sealed on. Length of water jacket, inches 6 8 12 15 25 Length over all, inches 12 14 - 19 22 33 Each $1.10 1.30 1.80 2.00 3.00 ',',-22. CONDENSER, Hopkins Reflux, with inner jacket 25 cm long. Excellent for quick condensation, as the cold water jacket in the center offers a large condensing surface to the vapor. Length of outside jacket, 27*£ em; total length, 38 em. (See Journal of the American Chemical Society, for December, 1908) 3.30 3224. CONDENSERS, Liebig's, of glass with rubber connections and adapter. No A B C D E F Length of water jacket, inches 10 12 15 20 25 30 Length of condenser tube, inches 20 22 25 30 37 42 Each » 1.10 1.30 1.40 1.70 2.30 2.60 322o. CONDENSER TUBES only for No. 3224, H inch in diameter. Length, inches ." 20 22 25 30 37 42 For condenser jacket, inches 10 12 15 20 A 25 30 Each 30 .33 .40 .45 '.60 .65 3228. CONDENSERS, Liebig's, all of glass, with inner tube permanently sealed to jacket, with adapter. Length of water jacket, inches 10 12 " 15 20 25 30 Length over all, inches 17 19 22 28 33 38 Each 1.40 1.60 1.90 2.50 3.50 4.50 02:>0. CONDENSERS, Liebig's, of glass, with coiled condenser tube sealed in water jacket, with adapter sealed on. ,. .. Length of water jacket, inches 8 12 15 25 Length over all, inches 14 19 22 33 Each 2.00 2.60 3.25 6.00 :;2.".2. CONDENSERS, Liebig's, of polished brass, 1% inches in diameter, fitted with glass condensing tube and rubber connections. Length of brass jacket, inches 15 20 30 Length over all, inches 25 30 42 Each 3.90 4.50 600 ::2:!4. CONDENSER, Soxhlet's Spherical, of copper, tinned inside and nickel-plated; diameter, 4 inches 3.60 .S236. CONDENSER. Sulphurous Acid, Fischer's, with two glass stop-cocks on vertical tubes 3.75 3238. CONDENSER, Sulphurous Acid, Liebig's, with two glass stop-cocks on horizontal tubes. . . . 3.75 3240. CONDENSERS, Zinc, with heavy block tin worm, for use with Distilling Apparatus No. 4148. No " A B C D E For still, capacitv, gallons % 1 235 Height over all, inches ti:^ 10% 14% 15% Diameter outside, inches 7 8% 9% 12% Diameter of tin tube, inches :is % % % % Each 5.50 7.00 8.75 11.50 15.00 3242. CORD, Chalk Line, Masons', i/$c inch; in hanks of 20 feet Per hank .08 3244. CORD, Fish line. Silk, braided, 25 yards on card -. .Per card .35 3245. CORD, Twisted Flax, fine quality, in %-lb. tolls Per ball .80 166 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 3246. 3248. 3250. 3252. 3253. 3256. Nos. 3246-56. CORES, XX Quality, regular length. No 0 1 2 3 4 5 6 7 8 9 10 Diam. at small end, inches . . %•> 9ie % ] %•> ]%., J%2 vie % J Wj % -%•> Per dozen $0.05 .05 .06 .07 .08 .09 .10 .11 .13 .15 .17 Per gross .30 .30 .35 .40 .45 .50 .55 .60 .70 .90 1.00 No 11 12 13 14 15 16 18 20 22 24 26 Diam. at small end, inches. . We % "He 1 m« 1%* 1%2 3 H4> I1 %2 115^,, 11%., Per dozen .19 .20 .22 .25 .30 .40 .45 .50 .60 .75 .85 Per gross 1.05 1.15 1.25 1.45 1.65 2.00 2.35 2.85 3.45 4.20 5.10 CORES, XX Quality, short taper. No 1 2 3 4 5 6 7 8 Diam. at small end, inches. . ll,^2 1%2 1%2 1%2 %6 % Hie % Per dozen .05 .05 .06 .07 .08 .09 .10 .13 Per gross .30 .30 .35 .40 .45 .50 .60 .75 No 9 10 11 12 13 14 Diam. at small end, inches . . . 2%2 1!He i * 1!Kf 1 I1/ifi Per dozen .15 .17 . 19 .21 , 21 .24 Per gross .85 .90 1, 10 1.15 1.25 1.40 No 15 16 18 20 22 24 26 Diam. at small end, inches. . 1% l^e 1 ^ie 1 Vie 1% ] %,; 1% Per dozen .27 .30 .35 .40 .45 .55 .65 Per gross 1.60 1.75 2.00 2.25 2.75 3.25 3.75 CORES, XXXX Quality, regular length, far superior for laboratory work to the XX or XXX quality in soundness and freedom from holes. No 0 1 2 3 4 5 6 7 8 9 10 DAam. at small end, inches. . %2 Per dozen , 08 Per gross 45 No Diam. at small end, inches. . 1 Per dozen 35 Per gross CORES, XX Quality, Nos. 0 to 11 assorted, in gross packages only Per gross .75 CORES, XX Quality, Nos. 12 to 26 assorted, in gross packages only Per gross 3.00 CORES, Selected Grade, regular length, finest quality, for use in chemical laboratories. An es- pecially light cork, practically free from holes, specially recommended for use in laboratories where distillations and extractions are made with volatile liquids. .08 .08 .09 .10 .11 .13 .15 .18 .22 .27 .30 .45 .45 .50 .55 .65 .75 .85 1.00 1.25 1.60 1.80 11 12 13 14 15 16 18 20 22 24 26 ;fte .35 % .38 .40 1 .45 .55 1%2 .65 1%2 .75 .90 11%2 1.15 H%2 1.40 H%2 1.70 1.00 2,10 2.30 2.70 3.05 3.80 4.50 5.10 6.80 8.40 10.00 No 0 1 2 3 4 B Diam. at small end, inches %2 'Ha % J%2 ]%2 n/6" Per hundred 45 .45 .55 .65 .80 1.00 Per bag of 500 2.00 2 .00 2.50 3.00 3.60 4.50 No 6 7 8 9 10 11 12 Diam. at small end, inches %p % Hie % 2%2 1;Hfi % Per hundred 1.10 1.35 1.60 2.00 2.25 2.35 2.50 Per bag of 500 5.00 6.00 7.20 9.00 10.15 10.75 11.25 No 13 14 15 .16 17 18 19 20 Diam. at small end, inches i%6 1 ~^ViK 1%2 !%:> 1%2 !%•> 1H&2 Per hundred 2.65 3.00 3.50 4.25 5.00 5.50 6.00 8.00 Per bag of 500 12.00 13.50 15.75 19.25 22.50 25.00 27.00 36.00 CENTRAL, SCIENTIFIC CO., CHICAGO. U. 8. A. 167 No. 3258. No. 3274. No. 3272. 3658. CORKS, Flat Specie Corks, XX Quality, with slight taper; for wide mouth bottles. No A B C D E Diam. at large end, in. % % 11% 1% Diam. at small end, in. % % % 11% Length, inches % % % % % Per dozen $0.16 .16 .18 .20 .25 Per gross 95 .95 1.05 1.20 1.50 F 1% .30 1.80 1% .35 2.10 H 1% .45 2.50 J 1% 1% .50 2.80 K 1% 1% .55 3.20 L 2 1% .65 3.70 2% 2 .75 4.25 .90 5.30 Q 2% 2% lio 6.40 T 2% 2% U 3 2% V 3% 3% W 4 3% X 4% 4% Y Z 5 6 4% 5% 1.25 7.25 1.45 8.30 3264. 3266. 3268. 3270. 3272. 3274. 3278. 1.60 1.80 2.75 4.00 5.50 7.00 10.50 9.30 10.30 16.50 24.50 32.50 41.00 65.00 inch, with punch $0.40 C 9 D 12 No N P Q E Diam. at large end, in. ZVt, 2% 2% 2% 2% Diam. at small end, in. 2% 2% 2% 2% 2% Length, inches % Per dozen 80 Per gross 4.75 CORK BORER, hard brass, smallest size, CORK BORERS, hard brass, in sets, with punch for each set. No A B Number in set 3 6 Diameter of borers, inches ^ie^e ^ie'Tie ?is'% ?W< Per set 60 L20 2.00 3.00 CORK BORERS, of hard brass in sets, with individual handles, and punch for each set. No A B C D Number in set 3 6 9 12 Diameter of borers, inches ?ie~^ie ?is~%6 %6~% $i«~% Pet set 1.05 2.00 3.50 5.20 CORK BORERS, of steel tubing, in seta, with individual handles, and punch for Borers differ by }4g inch in diameter. No A B Number in set 3 6 Diameter of borers, inches %-% %-%e Per set 1.25 2.50 3.50 CORK BORING MACHINE. Can be screwed firmlv to table. With this machine it is possible to drill rapidly both rubber and cork stoppers. Complete with 8 interchangeable steel drills of from %6 to % inch diameter 15.00 CORK BORER SHARPENER, steel cone with knife 1.75 CORK EXTRACTOR, folding form. Can be used in place of corkscrew. Especially valuable when corks have been pushed inside bottle 20 E 15 164.40 E 15 7.50 each set. C 8 168 CENTRAL SCIENTIFIC CO., CHICAGO, TI. 8. A. R.u.bbe.r Stoppers — orvct— Tapered Cbrk-3 No. 8146. No. 3320. 3280. 8146. 3286. 3292. 3296. 3298. 3300. 3304. 3306. 3308. CORK GAGE, of aluminum, for use in determining the proper size of cork or rubber stoppers for bottles, flasks, etc. For rubber stoppers from 00 to 12 and cork stoppers from 1 to 26 $0.10 CORK KNIFE, with good quality steel blade 4 inches long, and round wood handle 25 CORK MATS, Suberite, of compressed cork, for supporting beakers, etc. Diameter, 12 cm. Thickness, cm 1 2 4 Each , 30 .36 .60 CORK PRESSES, rotary form. No A B For corks up to, inches % 1%, Each 1.00 1.30 CORK RINGS, Suberite, of compressed cork, for supporting flasks, etc. Highly recommended as a substitute for straw rings on account of their appearance and durability. Diameter inside, mm 30 60 90 120 150 Each 28 .56 .80 .95 1.40 CORK SHEET, of compressed cork faced on both sides with white glazed paper. Designed especially for mounting insects in entomological work. Size of sheets 18x24xa4 inch. Per sheet 1.00 CORK SHEETS, XX Quality, size 4x12 inches. Thickness, inches % %Q ^4 Each 20 .30 .40 Per dozen 2.00 3.00 4.00 CORKSCREW, wood handle •. 10 CORKSCREW, self-pulling 50 CORKSCREWS, twisted wire Per dozen .10 3318. 3320. 3321. 3322. COUNTING APPARATUS COUNTER, Hand Tally, for use in counting colonies of bacteria, and for other laboratory opera- tions. Fits the fingers of the left hand as shown in the illustration. Registers up to 100,000 . 2.25 COUNTING APPARATUS, Stewart, for counting colonies of bacteria. Consists of a hardwood box 12x8x6 inches, in which is placed a 16-candle power incandescent lamp and an adjust- able support for carrying the Petri dish, illuminated by oblique rays from the lamp, which do not pass into the eyes of the operator. A ruled glass plate is provided on top of the box and the count is made by viewing the colonies on the Petri dish through the glass plate. (See Journal of Medical Besearch for January 1906) 12.00 READING LENS for use with No. 3320 1.50 RULED COUNTING PLATE only of No. 3320 6.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. 169 No. 3340. A B No. 3328. No. 3330. No. 8341. :;:ii4. COUNTING APPARATUS, Wolffhuegel's, for counting colonies of bacteria. Mounted on oak base with large drawer; furnished with background plates, black and white; surface of the plates is covered bv rulings 12 cm square $8.50 .-!.;^5. RULED GLASS PLATE only for No. 3324 3.50 3328. COUNTING PLATE, Frost's, printed in black with white lines, on good quality Bristol board. The cross lines divide the figure into square centimeters. Four of these, just above the cen- ter, are subdivided. The numbers, 40, 60 and 80, give the area of the disks bounded by the circles just below them. The area of each sector, a and b, is one-tenth of the area enclosed by its circle 10 3330. COUNTING PLATE, Jeffer's, similar to No. 3328, but divided by concentric circles into equal areas, which are subdivided by radii or segments of radii into smaller integral portions. The numbers refer to the number of equal sections within the area enclosed by the circle just beneath the number. Within the sectors a and b the areas enclosed between the three outer circles are further subdivided into half-spaces. (See Journal of Applied Microscopy and Laboratory Methods, Vol. I, No. 3) 10 8344. MAGNIFIER for use in counting colonies of bacteria, magnifying 2^ diameters. Recommended for use by the American Public Health Association. (See Standard Methods of Bacteriolog- ical Analysis of Milk, for 1916, page 5) 1.00 3336. CREMATOR, DeKhotinsky Electrically Heated, for flaming platinum loops. In inoculating cul- ture tubes or making sputum smears the spattering occasioned by flaming the platinum loop in the Bunsen burner flame is a source of great danger to the health of the operator. This trouble is entirely done away with in the DeKhotinsky Cremator, in which the flaming of the loops may be performed with perfect safety. The rapid flaming requires only a few moments and is complete, since the bright ted heat to which the loop is subjected removes all carbonized material. The apparatus consists of a tube of heat resisting material 4 inches long by % inch inside diameter, closed at one end and wound with Chromel wire. This tube is mounted in a neatly finished brass tube of 1% inches outside diameter, and the space between the two tubes is filled with magnesia-asbestos mixture. This tube is mounted on a base of asbestos board, fitted with binding posts for electrical connection and with a suitable support for the handle of the platinum loop. No A B For volts 110 220 Each 10.00 11.00 3340. CROSS SECTION CHART, made of extra quality blackboard cloth, with lines in white, accurately spaced and permanent. Its surface takes crayon marks and permits their erasure as easily as a blackboard. Can be rolled up when not in use. Size of ruled surface, 36x36 in 4.00 3344. CROSS SECTION PAPER, one millimeter divisions with heavy centimeter ruling. In sheets 17x17 cm on transparent onion skin paper. Per quire .30 3346. CROSS SECTION PAPER, accurately ruled, printed from an engraved plate. One millimeter divisions with heavier centimeter ruling; size 40x50 cm Per sheet .20 Per quire 4.00 3347. CROSS SECTION PAPER, same as No. 3346, continuous ruling in one millimeter divisions, 50 cm wide Per yard .33 3350. CROSS SECTION PAPER, ruled in ifoth inch divisions, size 16x21 inches Per sheet .08 Per quire 1.50 33o2. CROSS SECTION TABLET, containing 75 sheets of paper metrically ruled with heavy lines every cm and light lines every 2 mm, with note ruling and marginal line on opposite side .18 3354. POLAR CO-ORDINATE PAPER, printed from an engine divided plate, about 17 cm in diameter. Per quire .45 170 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Nos. 3368-70. No. 3372. CRUCIBLES, ALL KINDS 3360. CRUCIBLES, Alundum, for general laboratory use. These crucibles will stand any temperature available in the laboratory, and this with their high thermal conductivity, makes them valuable for eoal analysis, drying materials, igniting filters, etc. Furnished in fine mixtures only. No A B C D E Capacity, ce 10 20 25 30 40 Diameter, inches 1 Mo 1% IVa 1% 1% Height, inches 1%-. 1%6 1% 1% 1% Each $0.23 .30 .35 .35 .35 3361. COVERS, Alundum, for No. 3363 Crucibles. No B E For crucibles, cc 20 40 Each 30 .35 3364. CRUCIBLE, Alundum, specially designed for determining moisture in coal. Diameter, 2% inches; height, 1% inches; capacity, 80 cc ! 35 3366. CRUCIBLES, Alundum Filtering, for ranid filtration; save 75 per cent, of the time usually re- quired. Not affected by solutions of acids or alkalis and can readily be dried to constant weight. Recommended by Spencer for use in sugar analysis. Medium porosity carried in stock. Fine and coarse porosities can be supplied on short notice. No A B Capacity, ce 25 35 Diameter, inches '. 1% 1% Height, inches 1l/2 1 n/i6 Each 30 .35 3368. CRUCIBLES, Alundum Melting, highly' refractory, and well adapted to experimental electric furnace work. They are not suited for use where slags are encountered on account of their absorbent nature. Furnished in fine mixtures only, except No. 3368D which is porous. Price of No. 3368C includes cover. ' No A B C D Diameter, inches 1% 2% 2% 3 Height, inches 2 2% 4% 3% Each 75 1.00 2.00 1.25 3370. CRUCIBLE, Alundum Melting, similar to No. 3368, but of composition especially adapted for work requiring an extremely refractory body. Platinum has been melted in this crucible. Diameter, 1% inches; height, 3a/4 inches 1.50 3372. CRUCIBLES, Denver Fire Clay, for assay work ; without covers. No A B C D E Capacity, grams 5 10 15 20 30 Height, inches 2% 3 3% 3% 3% Diam. at top, inches 2% 2% 2% 3 3% Approx. number in original barrel 850 500 400 350 250 Per dozen 60 .75 .85 .95 1.40 Per 100 in original barrel 3.40 4.60 5.25 5.75 8.50 3373. COVERS for No. 3372V Per dozen 45 .45 .45 .65 .75 Per hundred in original barrel 3.00 3.00 3.00 4.50 - 5.00 CENTRAL SCIENTIFIC CO., CHICAGO. TT. S. A. 171 No. 3381. No. 3386. No. 3390. No. 3394. No. 3388. 3376. CRUCIBLES, Denver Fire Clay, high form, for gasoline or open furnace work; without covers. No D E F G J K L Height, inches 4 4% 5 5% 6% 7% 8 Diam. at top, inches 2% 3 3% 3% 4% 4% 5>4 Approx. number in original barrel 450 300 250 175 75 50 40 Per dozen $0.90 1.35 1.50 2.05 3.90 4.75 8.45 Per 100 in original barrel 5.25 7.95 8.90 12.30 23.40 28.45 50.50 COVERS for No. 3376. Per dozen 40 .55 .60 .65 .90 1.40 1.60 Per hundred in original barrel 2.75 3.90 4.00 5.25 6.50 10.50 12.00 3377. 3380. 3381. 3384. 3386. 3388. 3390. 3392. 3394. CRUCIBLES, Denver Fire Clay, tall narrow or French form; for gas or gasoline furnaces; 'with- out covers. No Height, inches Diam. at top, inches Approx. number in original barrel. Per dozen Per 100 in original barrel COVERS for No. 3380. Per dozen Per 100 in original barrel. 6 4 2% 450 .90 5.25 .45 3.00 8 5 300 1.65 9.75 .45 3.00 9 5% 3 250 2.10 12.60 .75 6.00 CRUCIBLE, Clay Filtering, C. M. Johnson's, very strong, resisting pressure. Will produce clear filtrates and withstand the full heat of a Meker burner. Especially adapted for use in de- termining vanadium and chromium. Diameter, 1% inches; capacity, 25 ce 1.25 CRUCIBLES, Copper, spun and polished, with covers. No :...' A B C D E Capacity, cc 20 30 50 100 250 Diameter, inches 1% 1% 1% 2% 3% Height, inches 1% 1% 2 2% 3% Each ...' 65 .75 .85 1.10 2.20 CRUCIBLES, Wrought Iron, light, with covers. Capacity, cc , Diameter, inches ." Height, inches Each 20 CRUCIBLES, Nickel, spun from pure sheet nickel, with covers. No A B Capacity, cc 20 30 Diameter, inches l1^ 1% Height, inches 1% 1% Each 1.20 1.35 .20 50 2% .22 100 2% 2 .36 C 50 1% 2 1.45 D 100 2% 2% 2.40 200 3% 2% .40 E 250 3% 5.00 CRUCIBLE, Nickel, Kawin's, of heavy pure nickel, for use in muffle furnaces for burning off filter paper in silica determinations in iron. Diameter, 28 mm; height, 15 mm 45 CRUCIBLE, Nickel, Pennock and Martin's, for the rapid and accurate determination of sulphur in coal and coke; consists of a pure nickel crucible of 40 ce capacity, with perforated lid for insertion of ignition wire, mounted upon an aluminum base. Diameter of crucible, 1% inches; height, 1% inches. (See Journal of the American Chemical Society, for December 1903, page 1265) 2.65 172 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. fl Hg^ _^_ _ m_ f"f~- ^~^ \ ) 1 j^^-r^S ^ ^ lr 1 p I..S.CQ. j f • VL ^ mi *a!sy No. 3396. Nos. 3400-1. Nos. 3404-5. No. 3408. No. 3411. No. 3412. For CRUCIBLES, Platinum, see Platinum Ware. 3396. CRUCIBLES, Plumbago or Black Lead, Dixon's, without covers. No. 0 00 000 0000 1 2 3 Capacity about, fluid ounces 1% 2348 12 16 Height outside, inches 2 2^4 2% 3 3% 4% 5% Diam. at top, outside, inches 1% 1% 2% 3% 3% 4% Each $0.65 .65 .65 .65 .80 .92 1.10 No .. ... 4 5 6 7 8 9 10 Capacity about, pints 1% 1% 2% 2y» 3 31/) 4 Height outside, inches 5% 6 6% 6% 7% 7% 7 in/ Diam. at top, outside, inches 4% 4% 5% 5% 5% 6 gi^ Each 1.45 1.67 1.95 2.14 2.43 2.70 3.00 3397. COVERS for No. 3396. To fit Crucible, No 0 00 000 0000 1 2 3 Each 30 .30 .30 .30 .42 .42 .42 To fit Crucible, No 4 5 6 7 8 9 10 Each .42 .42 .50 .50 .50 .50 .50 3400. CRUCIBLES, Best American Porcelain, high form, glazed throughout, without covers. No 000 00 0 1 2 3 4 5 Capacity, cc 5 10 15 30 57 95 155 280 Diameter at top, mm 26 30 35 41 52 62 72 87 Height, mm 19 25 27 35 43 50 59 72 Each 09 .12 .15 .24 .30 .35 .45 .55 3401. COVERS for Crucibles No. 3400. No 000 00 0 1 2 3 4 5 Diameter, mm 32 35 42 47 59 73 81 95 Each 05 .05 .05 .07 .09 .12 .12 .15 3404. CRUCIBLES, Best American Porcelain, wide form, glazed throughout, without covers. No 000 00 0 1 2 3 4 5 Capacity, cc 8 12 17 30 50 90 145 265 Diameter at top, mm 32 37 41 46 56 67 81 96 Height, mm •. 19 21 25 29 36 44 52 65 Each 12 .15 .18 .25 .34 .43 .50 .62 3405. COVERS for Crucibles No. 3404. No 000 00 0 1 2 3 4 5 Diameter, mm 39 44 47 52 65 76 88 107 Each 05 .05 .07 .07 .08 .12 .15 .18 3408. CRUCIBLE, Caldwell's Form, Best American Porcelain, with removable perforated plate to fit in bottom. Size No. 3; capacity, 25 cc. Without cover .55 3409. COVER only for No. 3408 .07 3410. PERFORATED DISK only for No. 3408 .20 PERFORATED DISKS, Platinum, for No. 3408 Crucibles, see Platinum Ware. 3411. CRUCIBLE, Best American Porcelain, Cylindrical Shape, glazed throughout except on outside- bottom surface. Diameter of rim, 30 mm; height, 32 mm; capacity, 15 cc .25 3412. CRUCIBLES, Gooch Form, Best American Porcelain, glazed throughout except outside bottom surface. Perforations about >/. mm in diameter. Without covers. No 2 3 4 Capacity, cc 10 25 35 Diameter at top, mm 27 35 40 Diameter at bottom, mm 18 22 25 Height, mm 30 40 43 Each 30 .40 .45 3413. COVERS for No. 3412. Diameter, mm 35 42 47 Bach 05 .05 .07 CENTRAL SCIENTIFIC CO., CHICAGO. TT. 8. A. 173 No. 3414. No. 3416. NOS. 3428-9. 3414. CRUCIBLE, Gooch, for Bitumen in Asphalt, Best American Porcelain, with large filtering sur- face. Height, 24 mm; width at top, 45 mm; width at bottom, 35 mm $0.50 3416. CRUCIBLES, Rose's, of unglazed porcelain, complete with perforated cover and delivery tube. Xo 1 2 3 Capacitv, cc 15 30 60 Diameter at top, mm 30 35 50 Height, mm 38 40 50 Each .50 .80 .90 3417. COVERS only of No. 3416. Xo 1 2 3 Diameter, mm 38 42 59 Each .10 .15 .20 3418. CRUCIBLES only of No. 3416. Xo 1 2 3 Each .20 .27 .30 3419. DELIVERY TUBES only, with flange, of No. 3416. No 1 2 3 Each .25 .40 .50 3422. CRUCIBLES, Transparent Quartz, of tall, narrow (so-called platinum) shape, 'without covers. No A B C D E F G H Capacity, ec 10 20 30 40 50 60 80 100 Diameter at top, mm 28 35 40 45 50 54 58 65 Each 3.60 6.00 8.40 10.20 12.00 13.80 16.80 19.80 3424. CRUCIBLES, Transparent Quartz, Gooch Form, same diameter as No. 3422 and with 7 holes 2 mm in diameter in the bottom. Without covers. No A B C D E F G H Capacity, cc 10 20 30 40 50 60 80 100 Each 5.40 9.00 12.60 15.30 18.00 20.70 25.50 29.70 3425. CRUCIBLE COVERS, Transparent Quartz, for Xos. 3422 and 3424 Crucibles. For crucibles, Xo A B C D E F G H Each 1.20 1.80 2.40 2.70 3.00 3.30 3.60 3.90 3426. CRUCIBLE COVERS, Rose's, Transparent Quartz, for No. 3422 Crucibles, with delivery tube. For crucibles, Xo. Each .. 3428. CRUCIBLES, Sand, Dixon's Assay, round form, without covers. Xo A B C Diameter outside, inches 1% 1% 2% Height outside, inches 2% 3 3% Each 10 .10 .10 Per 100 5.50 6.50 7.00 No J K L Diameter outside, inches 4% 4% 5% Height outside, inches 6% 7*4 8 Each 50 .55 .75 Per 100 40.00 45.00 64,00 3429. COVERS for No. 3428 Crucibles. No A B C D E Each 05 .06 .07 .07V2 .08 Per 100 4.50 5.00 6.00 6.50 7.00 No J K L M N Each . 15 .20 .21 .22 .24 A B 3.00 3.60 Sizes same as Battersea. D E F G H 2% 2% 3 3% 3% 4 4% 5 5% 5% .10 .15 .17 .20 .35 8.00 12.00 13.00 17.00 30.00 M N P Q B 5% 6% 7 7% 8% 8% 9% 10 11 12 1.00 1.25 1.80 2.50 4.00 80.00 110.00 160.00 220.00 350.00 F .10 8.50 P .26 G .12 10.00 Q .28 H .14 12.00 R .30 Per 100 13.50 16.50 18.00 19.00 20.00 21.00 24.00 25.00 174 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 3432. No. 3440. 3432. 3433. 3436. 3438. 3440. 3446. 3448. No. 3446. No. 3448. No. 3438. CRUCIBLES, Opaque Fused Silica, wide form, 99.8% SiO2. May be subjected continuously to temperatures up to 1200°C., and for short periods to much higher temperatures. Not affected by rapid changes of temperature, nor by acids, except hydrofluoric, and above 400 degrees C., phosphoric. No 000 Diameter, inches Height, inches Capacity, cc • 4 Each . . 00 1% 10 .75 0 1% 1 15 .75 1 1% 25 .94 2 2% 17/16 40 1.13 3 2% 1% 65 1.57 CRUCIBLE COVERS, Opaque Fused Silica. For crucible, No 000 Diameter, inches 1% Each . 63 00 1% .63 1 2% .75 2 2% .94 3 2% 1.13 CRUCIBLE, Opaque Fused Silica, Caldwell Form, with flanged bottom for perforated platinum or porcelain disk. Diameter at top, 1% inches; height, 1% inches 1.88 PERFORATED PORCELAIN DISK for No. 3436, see No. 5366. CRUCIBLES, Silver, spun from pure sheets, with cover. No A B C D E F Capacity, cc 20 30 50 75 100 150 Diameter, inches 1% 1% 1§4 2 2% 2% Height, inches 1% 1% 2 2& 2y2 2% Approx. weight, grams 35 45 '60 80 100 150 Each 3.75 4.80 6.30 8.40 10.80 15.75 CRUCIBLES, Skidmore's Normal School Retort and Crucible,' spun of thin iron enabling it to be easily brought to a red heat in the flame of an ordinary burner. Can be used as an open or closed crucible, or retort. Specially adapted for use in making oxygen, in oxidation and reduction experiments, and in dry or steam distillations. No A B Capacity, ounces 1% 6 Each 1.05 1.65 CRUCIBLE HOLDER for use with any ordinary 60 degree funnel. Especially efficient, as the ring covers only about % inch of the unper rim of the crucible. Can be used with Gooch, Cald- well, Alundum or Johnson's Clay Crucibles. Made of one piece of soft rubber. No A B For crucibles, top diameter, mm 27 35 Each . 30 .35 CRUCIBLE HOLDER, Bailey's, of rubber, to take No. funnel, as shown. Rubber holder only Gooch crucible. C 40 .40 For use with a 2 inch .35 CENTRAL SCIENTIFIC CO., CHICAGO. TT. S. A. 175 No. 3468. No. 3466. No. 3474, CRUSHING AND GRINDING APPARATUS The crushers, grinders, mills and pulverizers listed in this section have been carefully selected to meet every requirement of the experimental and testing laboratory. They are all American made and have been" in use for enough years under varied conditions to insure their serviceability and durability. In describing them, the attempt has been made in every case to state the particular uses for which they are best adapted, based on the experience of our trade. We wish to direct especial attention to the Brann line of crushers, grinders and pulverizers, of which a complete line is carried in stock for immediate delivery. 3460. CRUSHING PLATE, Bucking Board, of chilled iron, with rim, for powdering ores, rock, ete. Complete with rubber of same material with set-in wooden handle. No A B Size, inches 18x24 24x36 Weight, pounds 100 160 Each $10.00 17.50 3464. CBUSHING PLATE, Bucking Board, of hardest. Chrome Steel, with rubber of same material 8x7 inches, weighing 30 pounds, with wooden handle. Faces of plate and rubber are machined. Metal does not grind off into sample. Recommended by the Chemist's Committee of the United States Steel Corporation. Size, 18x24 inches; weight, 120 pounds. (See Journal of Industrial & Engineering Chemistry, Vol. I, No. 2, for February, 1909) 110.00 3466. CRUSHER, Weatherhead's, for hand operation, for crushing and pulverizing at one operation. Can be used for any material, from clay to pig iron. Cover of machine is designed for use as small hand mortar, using eud of handle as pestle. Diameter of crusher, about 12 inches; height, about 8 inches; weight complete, 100 pounds 25.00 3468. CRUSHER, Braun Simplex Ore, for hand operation, for crushing small samples of ore. Fineness of the product can be easily controlled by turning two regulating screws provided with hand- wheels. The machine can be easily cleaned by removing with one blow of a hammer a wedge which holds the stationary jaw in place; the entire operation of opening and closing can be completed in one minute. Crushing plates are of hardest steel, and can be reversed or easily renewed when necessary. Capacity, 100 pounds of ore per hour reduced to *4 inch and smaller. Height of machine over all, 18 inches; width, 15^ inches; length, 20 inches; size of jaws, 6x3 inches'; opening of jaws, 2 inches; diameter of wheels, 16 inches; shipping weight, 190 pounds. 40.00 CRUSHER, Simplex Ore, same as No. 3468, but for power as well as hand operation. Power re- quired, l-> h. p.; speed, 200 revolutions per minute. Shipping weight, 197 pounds 45.00 CRUSHER, Simplex Ore, same as No. 3468, but with tight and loose pulleys for power. . . . 57.00 CRUSHER, Chipmunk, Improved Type VC, for power, with all steel frames, rigidly secured together with strong studs. Bearings are of best phosphor-bronze which can be taken up when worn or easily renewed. The fineness of the product is readily controlled by the hand wheel in front. The stationary jaw lifts out permitting easy and thorough cleaning of interior. When operating, the vibratory jaw is given a forward and downward motion at lower end compelling the dis- charge of the crushed material. A special feature of this machine is its large capacity for the size of the jaws. Dimensions: length over all, 18 inches; height, 19 inches; width, 19 inches; size of jaws, 3x6 inches; opening of jaws, 2Vjx3 inches; dimensions of pulleys, lGx21o inches; speed, 400 revolutions per minute; power required to operate, 1 h. p.; capacity, 300^ to 400 pounds per hour ; shipping weight, 235 pounds 74.00 3470. 3472. 3474. 176 CENTEAL SCIENTIFIC CO., CHICAGO, II. 8. A. No. 3482. No. 3488. No. 3492. 3476. CRUSHER, Chipmunk Improved Type VC, same as No. 3474, but with tight and loose pulleys for permanent connection to line shaft or motor. Shipping weight, 270 pounds $85.00 3478. CRUSHER, Chipmunk Improved Type WC, of similar construction to No. 3474, but much larger. Dimensions: length over all, 22 inches; height, 26 inches; width, 22 inches; size of jaws, 9x4 inches; opening of jaws, 2%x4 inches; dimensions of pulleys, 20x3 inches; speed, 400 revolu- tions per minute; power required to operate, 2 h. p.; capacity, 1000 to 1500 pounds per hour; shipping weight, 460 pounds 132.00 3480. CRUSHER, Chipmunk Improved Type WC, same as No. 3478, but with tight and loose pulleys for permanent connection to line shaft or motor. Shipping weight, 515 pounds 149.00 Prices on renewal parts for Simplex and Chipmunk Crushers quoted upon application. 3482. GRINDERS, Braun Sample, for Rock, for hand operation. A laboratory machine which will pul- verize 4 ounces of hard quartz rock to 60 mesh in two minutes, or to 100 mesh in 3 minutes. All parts such as gears, are enclosed, making machines dust proof, eliminating danger, and prevent- ing loss of any material. Bucket is readily removed and revolving plate lowered to facilitate cleaning. Dimensions: height over all, 31 inches; width, 21 inches; diameter of hand wheel, 16 inches; diameter of grinding plates, 6 inches; shipping weight, 180 pounds. Complete with one set of grinding plates 70.00 3483. RENEWAL PLATES for No. 3482 per set 8.50 3486. GRINDER, Braun Sample, for Coal and Coke, for hand operation. Will pulverize 2 pounds of coal to 20 mesh in one minute, or 2 ounces to 80 mesh in five minutes; will reduce 2 pounds of coke to 20 mesh in 6 minutes, or 2 ounces to 80 mesh in 7 minutes. Shipping weight, 180 pounds. Complete with one set of grinding plates 75.00 Note: — This machine can be operated by power, using hand wheel as pulley. Power required, % h. p.; speed, 200 revolutions per minute. 3488. GRINDER, Braun Sample, for Coal and Coke, for power, same as No. 3486, but fitted with tight and loose pulleys for permanent installation. Shipping weight, 190 pounds. Complete with one set of grinding plates 85.00 3489. RENEWAL PLATES for Nos.' 3486 and 3488 per set 8.50 3492. GRINDER. Braun Sample, for Iron Ore, for power, with special 7 inch carbon steel grinding plates, with low phosphorus content. A high speed machine for power only; will pulverize 1 pound of iron ore to 100 mesh in 1% minutes. Equipped with special bearings, .heavy balance wheel and tight and loose pulleys. Dimensions: length over all, 24 inches; width, 16 inches; height, 31 inches; dimensions of pulleys, 7V£x2% inches; speed of pulle3Ts, 600*revolutions per minute; speed of grinding plates, 960 revolutions per minute; shipping weight, 290 pounds. Power required to operate, 1 h. p. Complete with one set of grinding plates 133.00 3493. RENEWAL PLATES for No. 3492, of carbon steel per set 23.00 3496. GRINDER, Braun Sample, for Iron Ore, for power, similar to No. 3492, but smaller and of lighter construction. Designed for intermittent use. Grinding plates, 6 inches in diameter, of special carbon steel, mounted vertically. Equipped with enclosed machine cut gears, and tight and loose pulleys, 12x2 inches. Dimensions: height over all, 31 'inches; width, 24 inches; shipping weight, 190 pounds. Speed of pulleys, 500 r. p. m.; of grinding plates, 800 r. p. m. Power required to operate, 1 h. p. Complete with one set of grinding plates 95.00 3497. RENEWAL PLATES for No. 3496 , per set 20.50 Note: — Prices on renewal parts for any of the preceding Sample Grinders quoted upon application. CENTRAL SCIENTIFIC CO., CHICAGO. TJ. S. A. 177 No. 3512. No. 3516. 3500. 3502. 3504. 3508. 3510. 3512. 3513. 3516. GRINDER, Laboratory Ore, with Hardened Steel Mortar and Pestle, for power, for reducing ore and rocks to an impalpable powder. The pestle is attached to a sliding rod held down by a spring at the top, so as to produce constant pressure on the mortar, which revolves slowly in the same direction as the pestle, producing a combined rolling and sliding motion similar to that in hand grinding. A scraper operates to keep the ore in the center of the mortar. By dropping one of the posts on the platform and raising the pestle, the mortar can be quickly removed. The machine is so constructed that no oil or foreign substance can contaminate the sample. Height of machine, 18 inches; diameter of mortar, 4*4 inches; power required to oper- ate, 14 h. p., at a speed of 250 r. p. m.; shipping weight, 40 pounds. (For complete descrip- tion see Bulletin 422, of the United States Geological Survey, "The Analysis of Silicate and Carbonate Rock," by W. F. Hillebrand, page 55) ..................... .' ............ $80.00 GRINDER, Hance Conical Plate No. 1, for hand operation, for grinding dry materials, such as drugs, grains, feed, coal, etc., to any degree of fineness down to 30 mesh. Grinder only for bolting to table, with 22-inch fly-wheel for hand power ............................. 50.00 GRINDER. Hance Conical Plate No. 1, same as No. 3502, but equipped with 10x3 inch tight and loose pulleys for power ............................................................ 50.00 GRINDER, Hance Conical Plate No. 2, for power, similar in construction to No. 3502, but much larger, with 14-inch grinding plates: mounted on substantial wooden support. Height over all, 48 inches; floor space, 18x31 inches; speed, 200 r. p. m.; power required to operate, 5 h. p.; size of pulleys, 12x4 inches; shipping weight, 385 pounds ............................ 125.00 GRINDING MILLS, Laboratory and Drug, for hand, operation, for grinding herbs, roots, grains, feed and other drv substances. Xo ........... ." Height, inches Diam. of wheels, inches Weight, pounds Each GRINDING MILL, for hand operation, for bolting fb table or bench. For pulverizing hard sub- stances for analysis, such as ores, bone, etc. Grinding surfaces are made of very hard mate- rial. Diameter of hand wheel, 19% inches; weight complete, 25 pounds ............... 17.70 EXTRA GRINDING PLATES for No. 3512 ................................... per set 4.00 GRINDING AND PULVERIZING MILL, for hand operation, for soils, grains, dry bone, lime- stone, rock phosphate, etc. Compact, strong, and durable. Height, 11 inches: length. 12 inches; width, 9 inches; dimensions of throat, 3x2 inches; diameter of handwheel, 19 inches; weight complete, 47% pounds ...................................................... 10.00 8% 15 6.30 3 15 10% 22% 9.40 5 17 12% 36 13.70 17 62 18.80 178 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 3518. 3520. 3522. No. 3534. No. 3536. GRINDING AND PULVERIZING MILL, for power, same as No. 3516, but fitted with single pulley, 12x3 inches $15.00 GRINDING AND PULVERIZING MILL, for power, same as No. 3516, but with tight and loose pulleys, 12x3 inches 20.00 GRINDING AND PULVERIZING MILL, Nixtamal, for hand operation, for soils, herbs, grains, coal, dry bone, limestone, etc. Will pulverize limestone fine enough to pass through a 100 mesh sieve. Capacity (grain) 5 pounds per minute. Total weight, 24 pounds. Complete with three sets of grinding disks, coarse, medium and fine 17.50 3524. GRINDING AND PULVERIZING MILL, for power, similar to No. 3522 but larger, with hop- per, and for power drive. Height, 24 inches; length, 12 inches; dimensions of pulley, 12x2% inches; speed of pulley, 300 r. p. m.; power required to operate, 2 to 3 h. p.; capacity per hour (cereals), 240 to 500 pounds; weight, 65% pounds 50.00 3526. GRINDING AND PULVERIZING MILL, for power, with automatic feed, adapted for grinding soils, coals, sand, gravel, stones, grit, cereals, etc. Will take large material and run either way, to right or left. The automatic feed is used for small material, while large pieces are fed directly into the mill. Height, 46 inches; height from floor to shaft, 24 inches; floor space, 23x30 inches; length over all, 36 inches; speed, 500 to 1000 r. p. m.; power required, 2 to 3 h. p.; dimensions of pulley, 8x4 inches; weight, 300 pounds; capacity per hour, 300 to 400 pounds 76.00 3528. GRINDING AND PULVERIZING MILL, for hand operation, specially designed for grinding small samples of wheat for flour analysis. Can also be used for coal, ore, grains, etc. Burrs are made of special hard steel alloy. Adjustable for different degrees of fineness. Parts can be easily taken apart for cleaning. For hand power, with crank handle of rolled steel, 9 inches in length. Shipping weight, 10 pounds 7.00 3530. GRINDING AND PULVERIZING MILL, for hand or power, same as No. 3528, but with hand- wheel, which can also be used for pulley. Flexible connection between hand-wheel and mill permits easy release of mill for thorough cleaning. Shipping weight, about 20 pounds 11.50 3532. GRINDING AND PULVERIZING MILL, for hand or power, same as No. 3530, but with a bolter which oscillates under outlet to separate ground material into two grades. With two interchangeable bolter boxes, each having a different grade of cloth. Shipping weight, about 25 pounds 21.50 3534. GRINDING AND PULVERIZING MILL, for power, same as No. 3532, but without handle, taking a 1 inch belt i 21.50 3536. GRINDING AND PULVERIZING MILLS, for power, same as No. 3534, but mounted on pedes- tal base with motor, for bolting directly to floor. Can be connected to any incandescent lamp socket. Shipping weight, 75 pounds. Complete with two bolter boxes. No A B C D A.C. B.C. For volts 110 220 110 220 Each 60.00 63.00 55.00 58.00 3537. EXTRA BOLTER BOXES for Nos. 3532, 3534, and 3536 each .80 CENTRAL SCIENTIFIC CO., CHICAGO. TJ. S. A. 179 No. 3552. No. 3554. 3540. GRINDING MILL, Enterprise No. O, for hand power, recommended by the Joint Enbber Insula- tion Committee, for grinding samples of rubber and insulating compounds for analysis. (See Journal of Industrial and Engineering Chemistry, Vol. IX, No. 3, for March 1917, page 313) $2.50 3342. MTIiT., Bagassee Cutter, for hand operation, for cutting slices from bagassee and other fibrous material for analysis. The thickness of the slices can be controlled by a special regulating device from thinnest shavings to slices % inch thick. With automatic feed 10.00 3544. MTT.T. Single Specimen Ball, for power, for pulverizing small samples of any material. Consist- ing of a porcelain jar with flint pebbles, mounted as shown with 9x1 inch pulley for power drive. Size of jar outside, 5.2x5.7 inches; floor space, 9x11 inches; speed, 80 to 120 r. p. m.; shipping weight, 50 pounds; capacity dry, *4 ounce to 1% pounds at a charge; capacity wet, 1'4 gallon 15.00 3546. 'MTT.T. Double Specimen Ball, same as No. 3544, but with two jars mounted to revolve on same axis. Floor space, 9x18 inches; shipping weight, 75 pounds 22.50 3547. EXTEA PORCELAIN JARS for Mills Nos. 3544 and 3546, size 5.2x5.7 inches; capacity, 1 quart each 5.00 3550. MTT.T. Single Bacilli, for power, with jars of special design for handling tubercle and other bacilli. Size of jar, 5.75x6.5 inches; size of pulley, 9x1 inch; floor space, 9x11 inches; speed, 80 to 120 r. p. m.; shipping weight, 65 pounds; capacity dry, % ounce to 2 pounds at a charge; capacity wet, i£ gallon 18.00 3552. "MTT.T. Double Bacilli, same as No. 3550, but with two jars mounted to revolve on same axis. Floor space, 9x18 inches; shipping weight, 90 pounds 27.00 3554. 'MTT.T. Single Assay, for hand or power, for reducing to an impalpable powder any materials, either hard or soft, particularly those which must not come in contact with metals. Widely •used in assay, cement, and soils laboratories. Size of jar, 8.75x9.65 inches; height of mill, 19 inches; floor space, 14x25 inches; size of pulleys, 9x1 inches; speed, 60 to 75 r. p. m.; shipping weight, 125 pounds; capacity dry, 1 ounce to 5 pounds at a charge; capacity wet, 1 gallon. With handle for hand operation 37.50 180 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 3556. No. 3562. No. 3564. No. 3558. 3556. MILL, Single Assay, with Specimen Jar, for hand or power. Size of assay jar, 8.75x9.65 inches; size of specimen jar, 5.2x5.7 inches; floor space, 14x35 inches; height, 19 inches; size of pulley, 9x1 inches; shipping weight, 140 pounds; speed, 60 to 75 r. p. m.; capacity of assay jar, dry, 1 ounce to 5 pounds; wet, 1 gallon; capacity of specimen jar, dry, 14 ounce to 1% pounds; we't, i/4 gallon. With handle for hand operation $48.75 3558. MILL, Double Assay, for hand or power, same as No. 3554, with two porcelain jars, 8.75x9.65, mounted to revolve on same axis. Floor space, 14x35 inches; shipping weight, 200 pounds. With pulley 9x1 inch for power, provided with handle for hand operation 67.50 3559. EXTRA PORCELAIN JARS, 8.75x9.65 inches, with capacity of 1 gallon. For Mills Nos. 3554 to 3558 each 10.50 3560. EXTRA PORCELAIN BALLS for Mills Nos. 3544 to 3558. Diameter, inches y2 % 1 Per pound 60 .60 .50 3562. MILL, Swift B Drug, for hand operation, easily adjusted to any degree of fine grinding; can be opened, cleaned and closed in 10 seconds without changing degree of fineness as adjusted. Can be used for a variety of materials, such as feed, cereals, roots, herbs, soils, etc. Capacity of hopper, 3 pounds; floor space, 24x24 inches; height over all, 30 inches; diameter of grinders, 7% inches; diameter of fly-wheel, 34 inches; weight complete, 115 pounds 35.00 3564. MILL, Grinding and Pulverizing, for power, with tight and loose pulleys. Can be regulated to grind coarse or fine while running. Adapted for grinding leather samples, cotton seed, cereals, feed, etc. Height, 20 inches; length, 15 inches; speed, 250 r. p. m.; power to operate, % h. p.; capacity of hopper dry, 5 pounds; capacity of grinder, i/j pound per minute; shipping weight, 73 pounds 30.00 3566. MILL, Rolling, Crown, for assay and dental laboratories. Eolls are of crucible steel, ground and polished; pinions are cut from steel bar. Eolls can be easily removed from frame. Di- mensions of rolls: diameter, 2 inches; length, 3 inches. Shipping weight, 54 pounds; dimen- sions of box, 18x11x8 inches 33.00 3568. MILL, Rolling, Crown, same as No. 3566, but mounted on heavy iron column. Dimensions over all, 49x17x17 inches; shipping weight, 150 pounds 41.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 181 No. 3600. No. 3602. No. 3604. No. 3608. 3570. TVTTT.T., Sugar Cane, for extracting the juice from cane or other plant materials. With 2 rolls, 4x4 inches; with single gearing for hand power. Capacity, 125 pounds of cane per hour.. . $50.00 3572. MTT.T., Beet Shredding, with knives and plates of steel. External parts tinned to prevent rust- ing. Easily taken apart for cleaning. Capacity, 4 ounces per minute. Weight, 18 ounces. . 1.75 3578. PULVERIZER, Braun, Type IT. A., with tight and loose pulleys for power use. The grinding plates are made of special alloy possessing a high degree of wearing quality and durability. They are specially designed to secure best possible service, and can be easily replaced. The large and small lugs (shown in the illustration) act as breakers and carriers while the outer surfaces effect the pulverizing. The grinding plates are held in place in such a way that no screw heads or bolt heads protrude, and can be quickly and easily removed. The machine opens up so that every particle of material can be brushed into the pan. The interior is smooth finished with all parts easily accessible for cleaning. The pulverizer is fed through a spout in the door and will take particles up to % mesh and reduce to 100 mesh at one grind- ing. Length of machine, 23 inches; width, 14 inches; height, 14% inches; size of pulleys, 9x2% inches; speed, 850 r. p. m.; power required to operate, 1 h. p.; shipping weight, 275 pounds; capacity (quartz ore), 1 pound to 100 mesh in 1 minute 108.00 3579. EXTRA GRINDING PLATES for Braun Pulverizer per set 8.50 For SAMPLERS, RIFFLE PLATES, etc., see Sampling Apparatus. 3590. CULTURE DISHES, Petri Plates, in pairs, of clear glass with thin flat bottoms, well annealed to withstand sterilizing. No A B C D E F G Diameter of upper dish, mm 50 75 90 100 100 120 150 Depth, mm 10 10 10 10 15 20 20 Per pair .23 .23 .26 .28 .28 .50 .64 3592. COVER, of Porous Earthenware, for culture dishes 100 mm in diameter, to prevent spreading of growth by water of condensation during incubation 20 3594. COVER, of Porous Earthenware, same as Xo. 3592, but glazed 25 3600. CULTURE DISHES, Moist Chambers, made of clear white glass, with cover. No A B Diam. of upper dish, mm 198 240 Depth of lower dish, mm 70 80 Each 2.25 2.50 3602. CULTURE DISH HOLDERS, Ravenel, of nickel-plated spring wire, to hold dishes 100 mm in diameter for incubation or sterilization. No A B To hold, dishes 3 6 Each 50 .60 3604. CULTURE DISH HOLDER, for 100 mm dishes, of polished copper, with inside tray for removing dishes. Size, 9 inches high by 4% inches in diameter 3.25 3605. CULTURE DISH HOLDER, same as No. 3604, but made of sheet iron 1.80 3608. CULTURE DISH HOLDER, for 100 mm dishes, round form, of polished copper, nickel-plated, with five shelves, door and handle. Size, 8x5 inches 9.00 182 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 3644. No. 3640. 3616. CULTURE FLASKS, Kollc, of Pyrex glass, with neek indentation to prevent the culture medium from flowing out. Extensively used in the preparation of typhoid vaccine. Capacity, 320 cc; number in original ease, 84 each $0.75 per dozen in original case 8.10 3618. CULTURE FLASK, Freudenreich's, with ground on cap. Capacity, 25 cc 55 3620. CULTURE FLASK, Freudenreich's, same as No. 3618, but with side" tube 75 3622. CULTURE FLASKS, Miquel, with flat bottom and ground on cap. Capacity, cc 50 75 Each 1.00 1.25 CULTURE SLIDES, see Microscope Accessories. CULTURE TUBES, see No. 13358 Test Tubes. 3628. CUPELS, Bone Ash, highly absorbent. Diameter, inches 1% 1% 1% Per dozen 45 .55 .60 Per 100 3 00 3.75 4.25 3630. CUPELS, Casite, extremely hard when cold, standing transportation without damage. When heated they become soft and as absorbent as the best bone ash. Diameter, inches ~: l1^ 1% • 1% Per dozen 25 .35 .40 Per 100 1.65 2.50 2.75 CUPEL HOLDER, see Blowpipe Apparatus. 3634. CUPEL RAKE, of iron, 24 inches long — '.'. 60 3636. CUPEL SHOVEL, of iron, 24 inches long 60 3638. CUPEL MOLDS, of brass, finely finished. Diameter, inches l1^ 1% 1% Each 1.75 2.00 2.25 3640. CUPEL MOLDING- MACHINE, Iler's, with foot pedal for securing pressures, leaving both hands free. Capacity, 500 cupels per hour. Shipping weight, 40 pounds. For both I1/! and IVi inch cupels ." i 30.00 3642. CUPEL MOLDING- MACHINE, same as No. 3640, but equipped for making 1^4 , 1%, 1% and 2 inch cupels 40.00 3644. CUPEL TRAY, of -iron, with detachable handle, for 16 cupels 1.00 CUPS, Annealing, see Annealing Cups. CUPS, Porous, for use with batteries, see Batteries. CUPS, Swimming, see Swimming Cups. CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 183 No. 3650. Nos. 3652-4. No. 3656. No. 3658. No. 3660. No. 3662. No. 3664. 3650. 3652. 3654. ' 3656. 3658. 3660. 3662. 3664. 3668. 3670. 3672. 3674. CYLINDERS, Hydrometer Jars, of heavy glass, with lip. Size B C D E P Height, inches 6 8 10 12 15 Diameter, inches 1% 1% 1%- 2 2 Each *0.30 .36 .40 .50 .65 CYLINDERS, Hydrometer Jars, of heavy glass, with flange. Size B C D E F Height, inches 6 8 10 12 15 Diameter, inches 1% 1% 1% 2 2 Each 30 .36 .40 .50 .65 CYLINDERS, Hydrometer Jars, of heavy glass, with flange ground to take glass plate. Size BCD E F G Height, inches 6 8 10 12 15 15 Diameter, inches 1% 1% 1% 223 Each 35 .40 .45 .55 .75 1.05 CYLINDERS, Hydrometer Jars, with enlarg?d top to prevent overflow. Size A B Height, inches 12 14 Diameter of body, inches 1% 1% Each '. 70 .80 CYLINDERS, Graduated, with double graduations to read up and down, with lip. Capacity, cc 5 10 25 50 100 200 250 500 1000 Graduated in, cc Mo Mo % % ! 2 2 5 1° Each 35 .40 .50 .60 .70 1.00 LIO 1.50 2.00 CYLINDERS, Graduated, Mixing Bottles, with glass stopper, up and down. Capacity, cc 10 25 50 100 200 250 Graduated in, cc Mo % % 1 2 2 Each 70 .90 1.10 1.20 1.50 1.65 G H 15 18 3 3 .95 1.50 G H 15 18 3 3 .95 1.50 H 18 3 1.75 C 16 .90* 2000 10 4.00 With double graduations to read CYLINDER, Graduated, for use with No. 7360 Brown-Duvel Moisture Tester. 500 1000 2000 5 10 10 2.60 3.00 6.00 Graduated to 2? .65 CYLINDER, Graduated, new design with enlarged top, for use with No. 7360 Brown-Duvel Mois- ture Tester. Reads directly in percentage of moisture up to 16 per cent., when 50 gram sample is used. (See Bulletin 56 of the United States Department of Agriculture) ...... 85 CYLINDERS, Graduated, decision or Normal, with single graduations, to meet the requirements of United States Bureau of Standards. With unofficial factory certificate. Capacity, cc ......................... 10 25 50 100 250 500 1000 Graduated in, cc ..................... Mo ui % 1 2 5 10 Each .................................. 1.50 2.30 2.60 2.30 3.40 3.75 5.30 Each with Bureau of Standards Certificate. 3.50 4.30 4.60 4.30 5.40 6.00 7.30 CYLINDERS, Graduated, Mixing Bottles, Precision or Normal, glass stoppered, with single grad- uations, to meet the requirements of the United States Bureau of Standards. With unofficial factory certificate. Capacity, cc ......................... 10 25 50 100 250 500 1000 Graduated in, ce ..................... Mo % % 1 2 5-10 Each .................................... 1.80 2.60 2.90 2.60 3.70 4.05 5.60 Each with Bureau of Standards Certificate. 3.80 4.60 4.90 4.60 5.70 6.75 7.60 GRADUATES, Conical, etc., see Graduates. CYLINDERS, Urinometer, see Urinometers. 184 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Nos. 3754-6. Nos. 3750-1. No. 3784. No. 3776. No. 3780. 3750. DEFLAGRATION GLOBE for combustions in oxygen. Diameter of globe, 9 inches; diameter of opening, 2 inches. Globe only $1.70 3751. SUPPORT and Cup for No. 3750 1.30 3754. DEFLAGRATION SPOON, of iron, with % inch cup. Length over all, 15 inches 07 3756. DEFLAGRATION SPOON, of brass, with % inch cup. Length over all, 15 inches 10 3758. DEFLAGRATION AND COMBUSTION SPOON, Parker's, with removable % inch cup which can be placed at one end for combustion and at the other for use in deflagrations. Total length, about 15 inches 15 DEFLAGRATION Spoons for Sodium, see Spoons. DESICCATORS 3770. DESICCATORS, Scheibler, with wide flanges and covers finely ground to fit. Diameter, inches 4 5 fi 8 10 Each 1.10 1.50 1.80 5.50 9.50 3772. DESICCATORS, Scheibler, for vacuum, same as No. 3770, but with tubulature in cover to take rubber stopper. Diameter inside, inches 6 8 10 Each 3.10 6.60 11.00 3774. DESICCATORS, Scheibler, same as No. 3772, but complete with rubber stopper, glass stop-cock, and desiccator plate with 26 mm holes. Diameter inside, inches 6 8 10 Each. 6.50 10.50 16.00 3776. DESICCATORS, Scheibler, same as No. 3772, but with glass stop-cock and hook ground in tubulature in cover. Diameter inside, inches 6 8 10 Each 6.50 10.00 14.50 l!778. DESICCATOR, Atwater, with triangle. Diameter inside, about 4 inches 3.50 JJ780. DESICCATORS, Fruehling and Schultz, with porcelain plate profusely perforated with small holes. Diameter inside, inches 8 10 Each 10.00 14 00 3782. DESICCATORS, Fruehling and Schultz, same as No. 3780, but with glass stop-cock and hook ground in cover. Diameter inside, inches 8 10 Each 14.00 18.00 3784. DESICCATORS, consisting of a bell jar ground to fit tightly upon a heavy glass plate. A porce- lain dish is supplied for containing the drying agent, and for holding dishes and crucibles. No A B Diameter of bell jar, cm 15 20 Diameter of porcelain dish, cm 12 14.5 Glass plate, cm square 20 25 Each 3.25 4.70 CENTRAL SCIENTIFIC CO., CHICAGO. U. 8. A. 185 No. 3796. No. 814. No. 3802. No. 3785. No. 3804. No. 3808. No. 3814. No. 3790. 3785. DESICCATOR DISHES, Acid Dishes only of No. 3784, of porcelain. Diameter, cm 12 14.5 Each $0.80 1.10 814. DESICCATOR, Triangular, for use in corner of balance case; of glass, 2 inches on a side, 1% inches high 1.00 3790. DESICCATOR CABINET, of glass, with wood frame carefully constructed to provide an airtight enclosure. Complete with three removable perforated steel trays. Finished in white enamel with nickeled trimmings. Dimensions inside: length, 12% inches; height, 10% inches; depth, 7ys inches 8.00 3794. DESICCATOR PLATES, of aluminum, with 7 holes, each 26 mm in diameter. Diameter, inches 4% 5^ 7% To fit desiccator, inches 5 6 8 Each 1.25 1.25 1.80 3796. DESICCATOR PLATES, porcelain, glazed on one side, with three small feet and with holes 26 mm in diameter; intended for use in Scheibler Desiccators. No 1 2 3 4 5 Diameter, mm 95 115 140 190 240 Diameter, approximate, inches 3% 4% 5% 7^ 9% Number of holes 3 4 5 6 8 Each 80 1.00 1.25 1.90 2.40 3798. DESICCATOR PLATES, glazed porcelain, with three small feet and with seven holes, each 26 mm in diameter. Diameter, inches 4% Each 1.00 3800. DESICCATOR PLATES, glazed porcelain, without feet; with holes 30 mm in diameter. Diameter, mm 190 Diameter, approximate, inches 7% Number of holes 7 Each 2.00 3802. DESICCATOR PLATES, glazed porcelain, profusely perforated with small holes. Diameter, mm 140 190 Each 1.25 2.00 3804. DESICCATOR TRIPODS, of glass, with feet, to stand inside desiccators, for holding dishes and crucibles. No A B C For desiccator, diameter, inches 4 5 6 Each 50 .60 .65 3808. DIALYZER, Bell Glass Form, consisting of open top bell glass, with large end covered with parchment paper, suspended in glass jar. Diameter of bell glass, 7.5 cm; size of glass jar, 5x7 inches 1.50 10040. DIALYZER PAPER, Parchment, of vegetable origin, medium thickness, in sheets 18x24 inches i per sheet .05 per quire .60 10042. DIALYZER PAPER, Parchment, genuine animal product in sheets 17x22 inches. . .per sheet 1.70 3814. DIAMOND for writing on glass, mounted in hard rubber handle 2.50 3815. DIAMOND for writing or etching on glass, with high grade, sharp diamond point, wooden handle and protecting cap 3.50 DIAMOND GLASS CUTTERS, see Glass Cutters. 3816. DIAMOND INK for writing on glass, in one ounce ceresine bottles 40 DIGESTERS, see Autoclaves. 5% 1.25 230 9 8 2.50 230 2.50 186 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 3820. No. 3822. No. 3828. No. 3830. 3820. 3822. 3828. 3830. 3832. 3834. 3830. 3842. No. 3832. No. 3834. No. 3836. DIES, Figures, of steel, from 0 to 9, for stamping steel, bullion, etc. Face, inches % %6 % Per set $0.65 .90 1.50 DIES, Letters, of steel, complete set from A to Z, and period, for stamping steel, bullion, etc. Face, inches % %$ % Per set 2.00 2.70 4.50 DISHES, ALL KINDS DISHES, Acid, see No. 3785. DISHilS, Aluminum, for milk analysis, see No. 3850. DISHES, Crystallizing, of thin blown glass, with flat bottom, straight sides, and ground edges. No A B C D E F G Approx. diameter, mm 50 80 100 125 150 190 250 Approx. depth, mm 35 40 50 65 75 95 125 Each 12 .15 .20 .36 .48 .80 1.85 DISHES, Culture, see Culture Dishes. DISHES, Evaporating, Resistance Glass, flat bottom, heavy walled, with lip; may be used instead of porcelain. No A B C D Diameter, mm 60 80 105 125 Approximate capacity, cc 50 100 200 400 Each 18 .26 .40 .60 DISHES, Evaporating, Best American Porcelain, highest quality, with lip, glazed inside and out- side up to No. 5; larger sizes glazed inside, but only partly outside. No 000 00 0 1 2 3 4 5 6 Diameter, mm 60 70 80 85 90 100 110 120 145 Approximate capacity, cc 35 60 80 100 140 175 210 300 385 Each 12 .18 .20 .30 .35 .40 .45 .55 .70 No 6A 7 8 8A 9 10 11 12 13 Diameter, mm 162 185 215 230 265 305 360 400 460 Approximate capacity, cc.... 535 765 1285 1430 2200 3250 5700 10000 16500 Each 80 .90 1.20 1.50 1.80 3.00 4.00 9.00 18.00 DISHES, Evaporating, Best American Porcelain, glazed inside, but only partly outside, with heavy welted rim and lip. No 12 13 Diameter, mm 400 460 Approximate capacity, cc 10000 16500 Each 12.00 20.00 DISHES, Evaporating, Best American Porcelain, shallow form, with lip, glazed inside but only partly outside. No Diameter, mm , . Height, mm Approximate capacity, cc Each 1 70 15 45 .20 2 80 20 60 .25 3 95 23 95 .40 4 105 30 160 .50 5 120 34 200 .60 140 40 350 .75 DISHES, Evaporating, Opaque Fused Silica, round bottom, glazed throughout, with lip. affected by sudden or extreme changes of temperature, nor by ordinary reagents. No A B C D E Diameter, mm 51 70 82 89 9? Depth, mm 21 25 30 22 30 Approximate capacity, cc 25 45 80 90 100 Each 1.25 1.45 1.57 1,70 2.00 7 160 48 550 .90 Not F 108 44 200 2.30 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 187 No. 3844 No. 1820. No. 1821. No. 3856. No. 3858. 3843. DISHES, Evaporating, Transparent Quartz, hemispherical, with lip. 3844. 3846. 3848. 3850. 2408. 1820. No A B C D E F Diameter, mm 30 50 60 75 100 125 Capacity, ec 10 25 50 100 200 250 Each $3.00 4.80 7.20 10.80 18.00 25.80 DISHES, Graniteware, flat bottom, with sloping sides. No A B C Approx. diameter, cm 15 ig 22 Manufacturer's rated capacity, quarts % 1 2 Each : 30 .35 .40 DISHES, Iron, see Sand Baths. DISHES, Lead, for use with hydrofluoric acid in etching glass. Diameter, mm 50 75 100 Each 09 .14 .20 DISHES, Lead, Bottle Caps, for moisture in milk. Used also in the ether extraction of confec- tionery, according to the new method proposed by the Association of Official Agricultural Chemists. (See Journal of the Asociation of Official Agricultural Chemists, Vol. II, No. 1 Part II, page 73.) No A B C Size, inches 2%x% 2%xl %6 3%*% Per 100 2.50 2.50 2.50 DISHES, Milk, Aluminum, with straight sides and flat bottom. No A B C D Diameter, mm 50 65 75 100 Depth, mm ... t 12 15 20 25 Each 20 .30 .36 .40 DISHES, Milk, Best American Porcelain, with straight sides and flat bottom, glazed inside and outside. No 1 3 4 Outside diameter, mm 45 69 72 Depth, mm 12 13 16 Capacity, cc 13 25 45 Each 25 .35 .40 DISHES, Moisture, Aluminum, with cover of same fitting outside. Cover can be fitted on bottom to keep parts together when dish is open. Extensively used in soil laboratories for determin- ing moisture. No A B 1821. 3856. 3858. Diameter, mm 50 63 Height, mm 22 44 Each 25 .30 DISHES, Moisture, Aluminum, same as No. 1820, but with dish and cover numbered to agree, ordering please state what numbers are desired. No A B Each 30 .35 C 89 50 .50 In C .55 DISH, Moisture, Aluminum, with flat bottom, sloping sides, and inverted cover fitting tightly on inside. Diameter at top, 55 mm ; height, 15 mm 50 DISHES, Nickel, spun from pure sheet, polished; round bottom, with lip. No A B C D Diameter, mm 50 70 89 100 Capacity, cc 40 100 200 300 Each 1.10 1.45 2.20 3.00 188 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 3860. No. 3862. No. 3866. No. 3864. No. 3868. No. 3870. No. 3872. No. 3874. DISH, Nickel. Sugar, see No. 834. DISHES, Platinum, see Platinum Ware. 3860. DISHES, Preparation, of clear white glass, low form, with loose fitting cover. No A Diameter, mm 50 Height, mm 30 Each $0.35 3862. DISHES, Preparation, Stender Dishes, with grooved covers ground to fit. No A B C D Diameter, mm 36 50 60 60 Height, mm 19 25 28 89 Each 14 " .18 .25 .25 3864. DISHES, Boasting, Denver Fire Clay, very shallow. Diameter, inches 3 4 5 6 Each 12 .15 .20 .30 Per dozen 1.20 1.50 1.75 2.75 3866. DISHES, Silver, spun from pure sheet, polished; round bottom with lip. No A B C D Diameter, mm 50 70 89 100 Capacity, ec 40 100 200 300 Weight about, grams 45 75 125 175 Each 4.75 8.90 13.10 18.40 3868. DISH, Staining, of glass, with cover and grooves to hold ten 3 inch slides. Length outside, 3% inches; width outside, 2% inches 30 3870. DISH, Staining, Embryological Cup, of solid glass with concavity in center, with one surface ground for writing. Dimensions 38x38x17 mm, with concavity 33 mm in diameter and 11 mm deep 08 DISHES, Staining, Syracuse Watch Glasses, see Watch Glasses. STAINING JABS, see Jars, Staining. DISHES, Stender, see Dishes, Preparation. 3872. DISH, Sugar, Opaque Fused Silica, flat bottom, without lip. Diameter, 51 mm; depth in center, 25 mm ; approximate capacity, 40 cc 1.56 3874. DISH, Tannin, Opaque Fused Silica, flat bottom, without lip. Used also for ashing coal. Diam- eter, 82 mm; depth in center, 25 mm; approximate capacity, 75 cc 1.56 DISHES, Weighing, see Balance Weighing Scoops. CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 189 Nos. 3880-2. 3880. 3882. 3884. 3888. 3890. 3891. 3894. 3896. 3898. 3900. 3902. 3904. 3906. 3908. 3910. 3912. 3914. No. 3900. No. 3906. No. 3904. No. 3912. DISSECTING INSTRUMENTS BLOWPIPE for zoological work, nickel-plated, 125 mm long $0-12 BLOWPIPE for zoological work, nickel-plated, 188 mm long with very small orifice; especially suited for very small vessels .25 BRISTLES, shoemaker's. Extra quality; useful as seekers for tracing out fine ducts and vessels per 100 .20 FOECEPS, Artery, Dressing Forceps, of steel, nickel-plated, with corrugated jaws. Length, 11.1 mm 1.40 FOECEPS, Artery, Dieffenbach's, self-closing, of steel, nickel-plated, with corrugated curved jaws. Length, 60 mm .85 FOECEPS, Artery, Dieffenbach's, same as No. 3890, but straight 85 FOECEPS, Bone Cutting, of steel, nickel-plated, very heavy and strong. The blades fit ac- •^curately and are easily separable for cleaning. Length, mm '. 200 225 Each 4.00 4.50 FOECEPS, Bone Cutting, of steel, nickel-plated, with strong curved blades. Length, 125 mm 1.50 FOECEPS, Dissecting, Fine, of steel, nickel-plated, with smooth handles; fine, straight, smooth- points. Length, 110 mm 10 FOECEPS, Dissecting, Fine, of steel, nickel-plated, with smooth handles; fine straight, smooth points. Length, 95 mm .25 FOECEPS, Dissecting, Fine, of steel, nickel-plated, with smooth handles; fine curved, file-cut points and guide pin. Length, 1 20 mm 50 FOECEPS, Dissecting, Fine, of steel, nickel-plated, with corrugated handles; fine, straight, file- cut points, with guide pin. Length, 115 mm 55 FOECEPS, Dissecting, Fine, of steel, nickel-plated, with corrugated handles; fine, curved, file- cut points, with guide pin. Length, 115 mm 65 FOECEPS, Dissecting, Medium, of steel, nickel-plated, with corrugated handles; medium fine, straight, corrugated points, with guide pin. Length, 115 mm 55 FOECEPS, Dissecting, Medium, same as No. 3903, but with curved points. . Length, 110 mm .60 FOECEPS, Dissecting, Heavy, of steel, nickel-plated, with corrugated handles; heavy, straight, corrugated points, with guide pin. Length, 115 mm 50 FOECEPS, Dissecting, Heavy, of steel, nickel-plated, with corrugated handles; heavy, straight, file-cut corrugated points, without guide pin. Length, 125 mm 50 FOECEPS, Blowpipe, Cover Glass. Pinning, Weight, etc., see general heading, Forceps. 190 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. ABC No. 3974. No. 3951 (full size). No. 3958. NO. 3926. No. No. Nos. No. No. 3932. 3934. 3936-8. 3940. 3942. No. No. No. 3944. 3946. 3948. 3920. HOOK AND CHAINS, triple hooks, nickel-plated, with sharp points $0.30 3924. KNIFE, Cartilage, all steel, nickel-plated, corrugated handle; 50 mm cutting edge. Total length, 165 mm 80 3926. KNIVES, Cartilage, Heavy, Prosecting Knives, with heavy, steel blade, extra thick at back, set in ebony handle. Length of cutting edge, mm 70 90 Each 90 1.00 3928. KNIFE, Cartilage, Large, all steel, with flat ground blade, 135 mm long. Suitable for cartilage work and large dissections. Total length, 250 mm 3.75 3932. NEEDLE, Dissecting, of steel with plain wood handle 110 mm long; with straight sharp point. Length, 130 mm per dozen .30 3934. NEEDLE, Dissecting, same as No. 3932, but with bent sharp point per dozen .35 3936. NEEDLE, Dissecting, best quality, with curved sharp point 30 3938. NEEDLE, Dissecting, same as No. 3936, but with curved blunt point 30 3940. NEEDLE, Dissecting, same as No. 3936, but with half spear point 30 3942. NEEDLE, Dissecting, with full spear point, with double cutting edge 30 3944. NEEDLE, Dissecting, with harpoon shaped point, with two cutting edges 30 3946. NEEDLE, Dissecting, hook shaped 30 3948. NEEDLE HOLDER, of brass, nickel-plated, with screw chuck, with one straight needle. Length, 85 mm .15 3950. NEEDLE HOLDEK, same as No. 3948, but with one bent needle 15 3951. NEEDLES, of steel, for use with Nos. 3948 and 3950 Holders. Length, 50 mm. Style A B C D Known as straight spear bent hook Per dozen .08 .45 .12 .25 OIL STONE for sharpening Scalpels and Knives, see Nos. 9608 to 9612. 3958. PAN, Dissecting, of tinned metal, with metal loops at the bottom for fastening limbs of animals during dissection; size, 285x235x25 mm, unlined 35 3959. PAN, Dissecting, same as No. 3958, lined with wax on bottom 55 3962. PAN, Dissecting, of heavy tinned metal, japanned, with metal loops for fastening limbs of ani- mals during dissection. Dimensions, 290x190x30 mm deep 40 3963. PAN, Dissecting, same as No. 3962, but with bottom covered with black wax, to which small objects may be pinned 60 3966. PAN, Dissecting, of seamless agateware. Dimensions, 300x200x30 mm deep 35 3967. PAN, Dissecting, same as No. 3966, but with bottom covered with cork, to which small objects may be pinned .55 RAZORS, Section, see Microtome Knives. 3974. SAW, Bone, of steel, nickel-plated, parts separable for sterilization. Length of blade, 200 mm; total length, 300 mm \ 3.30 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 191 B C Nos. 3984-8. D E No. 3980. No. 3982. C No. 3996. No. 3990. They are suitable 3080. 3982. 3984. 3988. 3990. SCALPELS Scalpels are carried in three grades. Grade C is made from a good grade of steel, carefully ground and sharpened, for the ordinary elementary laboratory work of the student. Grade B is made from carefully selected steel evenly honed. They are well finished, and can be used for the more advanced laboratory work by either student or instructor. Grade A is made of the best English steel, tempered with the greatest care. The blades are hol- low ground and finely honed. They will take and retain an edge such as is demanded for the most delicate dissections. They can be used in the most precise work in the private or research laboratory. SCALPELS, REGULAR SHAPE SCALPELS, Grade C, with black wood handles. No A Length of cutting edge, mm 25 Each $0.40 SCAIiPELS, Grade C, all steel, easily sterilized. No. . B 38 .40 C 50 .45 Length of cutting edge, mm 25 Each SCALPELS, Grade B, with ebony handles. No Length of cutting edge, mm Each SCALPELS, Grade A, with ebony handles. No A Length of cutting edge, mm 25 Each 65 SCALPELS, Grade A, all steel, easily cleaned and sterilized. No Length of cutting edge, mm Each .. SCALPELS, SPECIAL SHAPES 3996. SCALPELS, Grade A, with ebony handles. Style " A Length of cutting edge, mm 35 Each ... .60 A 25 .50 B 32 .65 A 25 .85 B 35 .70 B 32 .50 C 38 .65 B 32 .85 C 35 .70 .45 C 38 .50 D 45 .65 C 38 .85 D 10 .60 B 38 .45 D 45 .50 E 50 .70 D 45 .85 E 50 .80 192 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. SCISSORS, DISSECTING Dissecting scissors are carried in three grades, A, B, and C, and in three degrees of fineness, designated as fine, medium and heavy. Grade C scissors are made of ordinary cutlery steel, and are suitable for ordinary student labora- tory work. Grade B scissors are made of the best grade of cutlery steel, nickel-plated, and are suitable for precise and delicate work in the advanced and research laboratory. Grade A scissors are made of the best grade of cutlery, steel, finely finished. They are made with slide lock instead of screw lock, being easily separated for cleaning and sterilization. These scissors can be used for dissecting and surgical work where freedom from bacterial contamina- tion is essential. 4002. SCISSORS, Grade C, Heavy, nickel-plated, with screw lock, with straight sharp points. Length, 1 25 mm $0.45 4004. SCISSORS, Grade B, Fine, with screw lock. Fine, straight sharp points. Length, 110 mm. .85 4006. SCISSORS, Grade B, Fine, with screw lock. Fine, sharp points, curved upwards. Length, 110 mm 1.00 4008. SCISSORS, Grade B, Fine, with screw lock. Fine, sharp points bent at angle to side. Length, 110 mm 80 4010. SCISSORS, Grade B, Medium, with screw lock. Medium fine, straight sharp points. Length, 1 15 mm 85 4012. SCISSORS, Grade B, Heavy, with screw lock. Heavy, straight points, one sharp and one blunt. No A B C D Length, mm 125 140 150 175 Each 1.00 1.25 1.50 2.00 4016. SCISSORS, Grade A, Fine, with slide lock enabling them to be easily taken apart for cleaning and sterilization. Fine, straight, sharp points. Length, 115 mm 1.20 4018. SCISSORS, Grade A, Fine, with slide lock, with fine sharp points curved upwards. Length 115 mm 1.40 4020. SCISSORS, Grade A, Fine, with slide lock, with fine sharp points, bent at angle to side. Length, 115 mm 2.25 4022. SCISSORS, Grade A, Heavy, with slide lock. Heavy straight points, one sharp and one blunt. Length, mm ' 105 115 125 Each 90 1.00 1.10 4024 SCISSORS, Grade A, Heavy, with slide lock. Heavy straight points, both blunt. Length, 140 mm 1.50 4028. SCISSORS, Dissecting, Coronary Artery, screw lock. Fine, straight points, with one sharp and one probe point 1.50 4030. SCISSORS, Invertebrate Dissecting, for the most delicate work. Very fine, sharp points, with all metal handle. Length of cutting edge, 10 mm; total length of scissors, 140 mm 4.00 CENTRAL SCIENTIFIC CO., CHICAGO. TT. 8. A. 193 No. 4036. No. 4038. No. 4040. No. 4044. No. 4046. No. 4048. No. 4054. No. 4056. No. 4064. No. 4060. 4036. SECTION LITTER, of German silver, with blade 16x18 mm; total length, 100 mm $0.22 4038. SECTION LITTER, with two German silver blades, set in ebony handle. Width of large blade, 10 mm; width of small blade, 6 mm 50 4040. SECTION LITTER, similar to No. 4038, but with 6 mm blade only 50 4042. SECTION LITTER, with ebony handle, and thin, flexible, German silver blade, 12 mm wide .60 4044. SECTION LITTER, with ebony handle and thin, flexible, German silver blade, 20 mm wide .65 4046. SECTION LITTER, with ebony handle and thin, flexible, German silver blade, 38 mm wide .70 4048. SECTION LITTER, with ebony handle and perforated bowl 18 mm in diameter, for handling delicate specimens 60 SECTION RAZORS, see Microtome Knives. 4054. SEEKER or Probe, all steel, nickel-plated, with octagonal handle and bent, blunt point, as used in the anatomical laboratory of the University of Chicago. Length, 145 mm 35 4056. SEEKER or Probe, all steel, nickel-plated, with hexagonal handle. One end terminates in a fine, sharp point, while the other is curved, with sharp edge and sharp point. Length, 155 mm .40 4060. SHEARS, Cartilage, of steel, nickel-plated, with screw joint. Length of cutting edge, 60 mm; total length of shears, 230 mm 4^0 4064. TENACTJLTJM, ebony handle, steel shank, with tapering sharp hook. Length, 160 mm 45 4066. TEN ACTJLUM, same as Xo. 4064, but with steel handle. Length, 160 mm 90 DISSECTING INSTRUMENT CASES 4072. DISSECTING CASE, Leatherette, of best quality brown leatherette, almost equal to leather in appearance and durability, single-fold, lined with heavy cloth, and having cloth flaps, button fastener, and loops for 6 instruments 30 4074. DISSECTING CASE, Leatherette, similar to No. 4072, but two-fold, with loops for 12 instruments .55 4076. DISSECTING CASE, Morocco, of genuine morocco leather, two-fold, lined with velvet, and hav- ing chamois flaps, button fastener, and leather loops for 11 instruments 1.50 4078. DISSECTING CASE, Morocco, similar to No. 4076, but three-fold, with loops for 17 instruments 1.80 394 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 4086. No. 4092. No. 4098. No. 4100. DISSECTING INSTRUMENTS IN SETS The following sets have been made up of the instruments which have proved most popular for work in botany, zoology, anatomy, and histology. We will make up special sets to meet any requirements, using preferably the cases in the preceding list. 4084. DISSECTING- SET, consisting of No. 4072 single-fold Leatherette Case, with the following Grade B and C instruments; No. 3898 Forceps, No. 3932 Needle, No. 3934 Needle, No. 3980B Scalpel, No. 4002 Scissors and No. F661 Rule $1.35 4086. DISSECTING SET, consisting of No. 4072 single-fold Leatherette Case, with the following Grade B and C instruments: No. 3898 Forceps, No. 3948 Needle Holder, No. 3950 Needle Holder, No. 3980B Scalpel, No. 4002 Scissors, and No. F661 Rule 1.60 4090. DISSECTING SET, consisting of No. 4072 single-fold Leatherette Case, with the following Grade B instruments: No. 3904 Forceps, No. 3906 Forceps, No. 3948 Needle Holder, No. 3950 Needle Holder, No. 3984C Scalpel, No. 4004 Scissors, and No. F661 Rule 3.25 4092. DISSECTING SET, consisting of No. 4074 two-fold Leatherette Case, with the following Grade B and C instruments: No. 3898 Forceps, No. 3902 Forceps, No. 3932 Needle, No. 3934 Needle, No. 3980B Scalpel, No. 3980C Scalpel, No. 4002 Scissors, No. 4004 Scissors, No. 4064 Tenaculum, and No. F661 Rule 3.85 4094. DISSECTING SET, consisting of No. 4074 two-fold Leatherette Case, with the following instru- ments: No. 3902 Forceps, No. 3914 Forceps, No. 3980A Scalpel, No. 3980C Scalpel, No. 4002 Scissors, No. 4004 Scissors, No. 3948 Needle, No. 3950 Needle, No. 8978 Section Razor with folding handle, and No. F661 Rule 6.50 4096. DISSECTING SET, consisting of No. 4076 two-fold Morocco Case, with the following Grade A in- struments: No. 3904 Forceps, No. 3906 Forceps, No. 3924 Cartilage Knife, No. 3948 Needle, No. 3950 Needle, No. 4056 Seeker and Tenaculum, No. 3988C Scalpel, No. 3996A Scalpel, No. 4010 Scissors, and No. F661 Rule 6.50 4098. DISSECTING SET, consisting of No. 4078 three-fold Morocco Case, with the following instru- ments: No. 3908 Forceps, No. 3912 Forceps, No. 3914 Forceps, No. 3990A Scalpel, No. 3990B Scalpel, No. 3990D Scalpel, No. 4004 Scissors, No. 4006 Scissors, No. 4012A Scissors, No. 3924 Cartilage Knife, No. 4066 Tenaculum, No. 4056 Seeker, No. 3920 Triple Chain and Hook, No. 3880 Blowpipe, 2 No. 3890 Artery Forceps, No. 3891 Artery Forceps, and No. F661 Rule. . 14.00 4100. DISSECTING SET, Anatomical, consisting of No. 4076 two-fold Morocco Case and the following Grade A instruments: No. 3882 Blowpipe, No. 3914 Forceps, No. 3890 Artery Forceps, No. 3924 Cartilage Knife, No. 4054 Probe, No. 4056 Seeker and Tenaculum, No. 3988C Scalpel, No. 3996A Scalpel, No. 3996B Scalpel, No. 4012D Scissors, No. 3920 Triple Chain and Hooks, and No. F661 Rule 900 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 19o No. 4120. 4138. 4102. DISSOLVING TUBE, Freas, for dissolving solids which are difficultly soluble without the aid of heat or mechanical agitation, and filtering the solution at the same time. The crystals are placed in A upon a plug of asbestos or cotton. Suction is applied at B, which is then closed, and a circulation starts upward through D and E down through C and F on account of the different densities of the liquids. This will continue until the entire solution is of the same density. Length over all without stop-cock, 37.5 cm; capacity, about 250 cc. With stop-cock, but without bottle or rubber tubing $5.00 DISTILLING APPARATUS FOR WATER 4120. DISTILLING APPARATUS, Acme Automatic Water Still. Made to hang on wall and can be placed wherever gas and water connections may most conveniently be made with pipes or rub- ber tubing. Occupies space 12x4 inches on the wall, projecting only 14 inches in its widest part. Fitted with removable cover to permit inspection if desired. Arranged to secure maxi- mum amount of water for the minimum consumption of gas. Made of copper and brass, tin lined and nickel-plated. Capacity, one gallon per hour and one half. With gas burner. 25.00 4122. DISTILLING APPARATUS, Automatic Water Still, of heavy spun copper, nickel-plated, without seams. Can be used on Tripod No. 4123 over Buusen burner or any convenient source of heat. Diameter of still, 11 inches; height, 13 inches; capacity, 3 quarts per hour with burner using 10 cubic feet of gas. With block tin outlet tube; without burner 29.00 4123. TRIPOD SUPPORT for No. 4122 Distilling Apparatus. Diameter of rim, 10 inches; height 7 inches 1.75 4136. DISTILLING APPARATUS, Peerless Automatic, built on an entirely new principle, as the boiler is so shaped that the steam is forced through the water to its center where it passes in a compact body into the condensing tube, thus reducing the amount of condensation on the side walls of the still. Because of this feature, it produces distilled water at a very low expense for gas. The parts are readily accessible for cleansing. The boiling vessel is of cast iron and not easily burned out or injured, by rough handling. The condensing tube is of heavy tinned copper, suf- ficiently large to insure perfect condensation with a very small stream of water. Finished in bright aluminum and lacquered brass. With gas burner. Capacity, gallons 1 3 Each 21.00 42.50 4138. DISTILLING APPARATUS, Ralston's New Process. May be used on any stove and does not require water under pressure. The storage of the distilled water within the still prevents th? reabsorption of gases. Although not entirely automatic, it is so constructed that it cannot boil dry; it requires little care or attention. It is made of copper and pure tin. Capacity, from 1 to 3 quarts per hour, depending on the amount of heat used. Weight, 7 Ibs.; diameter, 9 inches; height, 14 inches , 12.00 196 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 4126-7. (Patent Pending). Sectional Diagram Showing Details of Construction. 4126. 4127. DISTILLING APPARATUS, Cenco Polar, Electrically Heated. This still has been scientifically designed and carefully constructed in accordance with well established engineering principles relating to the efficient evaporation and condensation of water, and possesses certain features not found in other stills. The condenser has no tubes to become limed up or leaky but consists of three concentric cyl- inders; the outer one forming the jacket of the still is cooled by radiation, while the inner two are cooled by a constant stream of water circulating between them in a spiral motion. The boiling chamber is designed to maintain a small volume of water at constant level, spread out to afford as large a surface as possible for evaporation. The vapor flue, through which the steam from the boiling water ascends, is high and wide, preventing any carrying over of impurities due to foaming or bursting of bubbles, or to the velocity of the vapor. The steam separator at the top of this flue efficiently separates the dry vapor from the liquid particles, rolling them back into the boiler. The high temperature of the cooling water — from 160° to 180°F. — which is made possible by the large area of condensing surface, effectually cooks out of the raw water any odors or dissolved gases, which pass out through vents in the cover of the still. This hot water is slowly fed to the boiler as required and consumes but little heat in bringing it to the boiling point. The heaters are of the well known Westinghouse Bayonet type, designed for greatest efficiency. The interchangeable base makes it possible to lift out the top part of the Cenco'Polar Still and set it in another base, equipped for gas or steam heat. This is a feature peculiar to the Cenco Polar Still. All parts of the still are easily accessible for cleaning, as the still can be taken apart without difficulty and can be set up when received with equal ease. The heat exchange, just above the outlet for distilled water, reduces the temperature to within a few degrees of that of the room. By throttling down the supply of cooling water, distilled water at any temperature up to 200°F. can be obtained. The coil of block tin pipe, through which the distilled water passes on its way through the heat exchange, is surrounded by the cold condensing water just as it enters the still from the tap; consequently there is no oppor- tunity for vapor to escape. An aerator can be supplied at a small additional charge when it is desired to use the distilled water for drinking purposes. Complete as described, constructed throughout of cold rolled copper heavily tinned, with West- inghouse Bayonet Heaters, attachment cord and three-heat switch for use on either A.C. or D.C. circuits. Sizes A to C are nickel-plated outside; D to F are furnished in burnished cop- per. All stills are furnished on flat base as illustrated, but may be had mounted on legs with- out extra charge if specified when ordering. Wall brackets are furnished for attachment to the wall at a small extra charge as listed below. With full instructions for setting up and operating. No A B C Capacity, gallons per hour 1 2 3 Height, inches 12 13% 15 Diameter, inches 10 11 12 For 110 volts $80.00 125.00 225.00 375.00 For 220 volts 87.50 132.50 235.00 375.00 D 5 20 E 10 28 15 700.00 700.00 F 15 32 18 900.00 900.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A, 197 No. 4132, sho-wing construction. No. 4133, shown mounted on legs. EXTRA ELECTRIC HEATERS for Nos. 4126 and 4127. Tor No A B C D E P 4128. Each, for 110 volts $30.00 35.00 45.00 50.00 60.00 75.00 4129. Each, for 220 volts 37.50 42.50 45.00 50.00 60.00 75.00 4130. AERATOR, for use with Cenco Polar Stills, for the introduction of pure sterile air into the water when desired for drinking purposes. For No A B C D E F Each 4.50 5.50 6.50 7.50 9.50 14.00 4131. WALL BRACKETS for use with Cenco Polar Stills, for attachment to wall. For No A B C D E F Per pair 6.00 6.50 7.00 8.00 8.50 9.50 4132. DISTILLING APPARATUS, Cenco Polar, same as No. 4126, but equipped with interchangeable base and burner for coal or natural gas. Finished in burnished copper and polished brass. No A B C D Capacity, gallons 1 2 5 Each 60.00 100.00 125.00 175.00 4133. DISTILLING APPARATUS, Cenco Polar, same as No. 4126, but equipped with interchangeable base and steam coil for steam heat, under a pressure of 10 to 20 pounds. Finished in bur- nished copper. No A B C D Capacity, gallons 1 2 5 Each 60.00 100.00 125.00 175.00 Note: — Nos. 4132 and 4133 may be had in nickel-plated finish at an additional cost of $5.00. STILLS OF LARGE CAPACITY We are prepared to furnish information and prices upon distilling plants of large capacity, up to 1000 gallons per hour. We can place at the disposal of prospective purchasers the engineering knowledge and technical skill of the Jewell Polar Company, gained through years of successful experience in still design and manufacture. Write us at length about your particular problem. 398 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 4148. No. 4142. No. 4152. No. 4153. 4142. 4148. 4149. 4152. DISTILLING APPAKATUS, Stokes Automatic, steam heated. These stills have two features which render them unusually effective in the production of pure distilled water. First, they utilize the heat generated in the still to preheat the incoming water to the boiling point, thus requir- ing a very small quantity of live steam to keep them in operation after once started. Second, by preheating the feed water before it enters the distilling chamber ammonia and other gases are liberated and permitted to escape into the atmosphere through an opening in the condenser provided for this purpose, preventing their reabsorption by the distilled water. The distilling chamber and condensing cylinder are of cast iron galvanized to withstand corrosion. The con- denser tubes are brass, heavily tinned inside and out. These stills may readily be flushed for cleaning by means of a valve connecting with the drain, or the copper lid may be removed and the inner chamber scrubbed. They are self-contained, requiring only the two connections for steam and water, and are shipped ready to set up. Capacities are based on a steam pressure of at least 20 pounds. B 2% 4 no 65.00 No. Capacity per hour, gallons Height, feet Weight, pounds Each . C 5 D 10 35 $27.00 110.00 325 165.00 E 25 7 7.10 275.00 F 60 1200 500.00 G 100 71/2 1500 650.00 DISTILLING APPARATUS FOR SPECIAL USES DISTILLING APPARATUS, copper retort, tin lined, with removable head, connected with pure block tin condensing worm, enclosed in zinc vessel, with proper inlets and outlets. 12.85 B 1 17.00 C B 1 10.00 22.05 C 2 13.30 D 3 29.25 E No. Capacity, gallons Each RETORTS only of No. 4148. No A Capacity, gallons % Each 7.35 CONDENSING VESSEL only of No. 4148, s?e Condensers No. 3240. DISTILLING APPARATUS, for the destructive distillation of heavy oils and other liquids or solids requiring a high heat. The distillation may be made by live steam or by direct heat, with or without agitation by hot air blown through as desired. The still is of heavy cop- per with brass fittings. Capacity, % gallon 17.50 D 3 17.75 39.00 E 5 24.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 199 No. 4156. No. 4168. No. 4170. No. 4172. No. 4158. No. 4160. No. 4162. 4153. DISTILLING APPARATUS, similar to No. 4152, but larger and heavier, with cover bolted on and jointed delivery tube. (For illustration, see page 198.) No A B C D Capacity, gallons 1 2 3 5 Each . ". '. $26.50 39.60 46.20 52.80 4156. DISTILLING APPARATUS, for destructive distillation of oils, heavy liquids and solids at high temperatures. Made of heavy copper with brazed seams; with flanges held together by 6 thumb screw clamps. Can be easily taken apart to remove residue. No ". A B C Capacity, gallons • % 1 2 Each . '. 33.00 37.50 49.50 4158. DISTILLING APPARATUS. Hortvet's, for determining volatile acids in wines or vinegars, designed by Dr. Julius Hortvet of the Minnesota State Food and Dairy Commission. (See Journal of "industrial and Engineering Chemistry. Vol. 1, No. 1, for January 1909, page 31) Y 8.00 4160. DISTILLING APPARATUS. Hulett's, for Mercury, as used by the United States Bureau of Mines. Consists of a 500 ec flask with long neck ending in a stop-cock, side tube, condens- er and receiver with ground connections. (See Bulletin 42 of the United States Bureau of Mines) 12.00 4162. DISTILLING APPARATUS, Salleron's, of copper, for use in the determination of the per- centage of alcohol in wine, beer, cider, etc. Capacity, y3 pint. Complete with alcohol lamp, hydrometer reading from 0 to 100 degrees Proof and Tralle and 100 cc graduated cylin- der 13.00 Note: — For HYROMETERS for Beer, see No. 7676. DISTILLING APPARATUS for the determination of ammonia in water, see Water Analysis Apparatus. 4168. DISTILLING TUBE, for fractional distillation, plain form; length, 9 inches; diameter, % in. .20 4170. DISTILLING TUBE, with one Isulb; length, 8 inches; diameter, % inch 36 4172. DISTILLING TUBE, with two bulbs; length, 10% inches; diameter, % inch 50 200 OENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 4174. No. 4176. NO. 4178. No. 4180. No. 4182. No. 4184. No. 4186. No. 4188. 4180. 4182. 4184. 4186. 4188. DISTILLING TUBE, Glinky's, with glass valves. Length over all, 15 inches $2.40 DISTILLING TUBE, Hempel's, filled with glass beads. Length over all, 16 inches 3.50 DISTILLING TUBE, Knight, for use in the separation of xylenols and higher homologues from phenol and the cresols. The dimensions are so proportioned as to provide a layer of liquid in the bottom bulb which serves as a condensing medium for the xylenols and higher homo- logues, while allowing the phenol and cresols to pass through. (See Journal of Industrial and Engineering Chemistry, Vol. X, No. 1, for January 1918, page 16) 2.25 DISTILLING TUBES, LeBel-Henninger's. No Number of bulbs Each A 2 1.50 B 3 2.00 c 4 2.50 D 5 3.00 DISTILLING TUBES, Wurtz's, with two bulbs. Length over all, 12 inches 90 DISTILLING TUBES, Young's Form, for the distillation of small quantities. With rod and 15 disks. Length over all, 18 inches 3.00 DISTILLING TUBE, similar to No. 4184, but with 20 disks and 21 constrictions. Length over all, 18 inches 4.50 DISTILLING TUBES, with pear-shaped bulbs. No A B Number of bulbs 4 12 Length over all, inches 10 20 Each 3.00 4.50 NO. 4192. No. 4194. No. 4196. 4192. DIVIDER, Plain, of brass. Length, 4% inches 60 4194. DIVIDER, Spring. The popular Yankee polished steel spriflg divider, 5 inches long 50 4196. DIVIDER, Wing, of polished steel, sharp points, 6 inches long, with set screw 40 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 201 No. 4202. No. 4204. No. 4218. No. 4220. No. 4222. DRAWING INSTRUMENTS 4200. DRAWING BOARDS, pine wood, with side ledges clamped. No A B C Size, inches 16x22 20x24% 23x31 Each $1.25 1.50 2.25 DRAWING COMPASS, steel spring bow pencil compass. Made of German silver, nickel-plated. Steel points, metal handle ; length 3 % inches $1.25 DRAWING DIVIDER, steel spring bow divider. Metal handle, steel points; length, 3% inches. 2.10 4202. 4204. 4214. DRAWING INKS in the following colors: blue, brick red, brown, carmine, green, indigo, orange, scarlet, vermilion, violet, yellow and waterproof black Per % ounce bottle .35 In ordering please state the color desired. 4215. DRAWING- INKS in nicely finished hardwood tray. Choice of five different colors, selected from list under Xo. 4214 2.30 In ordering please state the colors desired. 4218. DRAWING INSTRUMENTS for elementary work, of brass, in cloth covered case lined with vel- vet. Contains ruling pen, 5-inch; compass, 4%-inch, with fixed needle point, pen and pencil points and lengthening bar; and plain dividers, 3%-inch 2.50 4220. DRAWING INSTRUMENTS, of German silver with steel points, in cloth covered ease lined with velvet. Contains ruling pen, 5%-inch; compasses, 6-inch, with fixed needle point, pen and pencil points and lengthening bar; dividers, 4^-lnch; bow pen, 3-inch; and box of leads 7.50 4222. DRAWING INSTRUMENTS, of German silver, American made, of excellent quality, design and finish, in cloth covered case lined with velvet. This is a high grade set; greatly superior to the cheaply made imported sets. All points and blades are ground and polished to the exact de- gree of fineness required to secure the best results. Complete with 5%-inch ruling pen with aluminum handle; e^-inch compass and divider of improved design, with 4-inch lengthening bar, pencil and pen points; handle for use with pencil and pen points for ruling work; 3%-inch bow pen; box of leads; hollow handled screw driver and extra points for divider 10.65 202 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 4224. No. 4230. No. 4238 (in use). No. 4244. HHHHHH *• PARAGON DPAWIN. No. 4236. No. 4242. 4224. DRAWING PEN, Bow, steel spring, with steel points and metal handle $2.25 4226. DRAWING PEN, Ruling, spring blade, metal handle 1.75 4230. BLACKBOARD DRAWING INSTRUMENTS a set of four pieces, consisting of a 24-inch T square, a 36 inch straight edge, a 24-inch triangle graduated in inches, and a 15% inch protractor. Per set 4.50 4231. T SQUARE only of No. 4230. l.OQ 4232. STRAIGHT EDGE only of No. 4230 75 4233. TRIANGLE only of No. 4230 1.50 4234. PROTRACTOR only of No. 4230 2.10 4236. BLACKBOARD COMPASS, of wood, 15 inches long, with crayon holder and rubber foot. . .60 4238. BLACKBOARD T-SQUARE, Upright T-Square, for use in making mechanical drawings on a blackboard. This device fits into the ordinary chalk tray and is provided with two sets of guid- ing rollers which keep the blade parallel to the blackboard and yet free from it. An adjust- able slide is provided for drawing horizontal lines and both vertical and horizontal blades are graduated. The Upright T-Square is used in the same manner as the Draftsman 's T-Square and is of service in any subject requiring drawings, sketches, plots, tabulations or diagrams. No Length, inches For blackboard height, inches Each 4240. DRAWING PAPER, slightly grained surface. No Size sheet, inches Per quire 4242. DRAWING PENCILS, Faber, polished. No Each 4244. RULES, Parallel, ebony. Length, inches Each A 15x20 .80 B 19x24 1.00 40 42 4.25 C 22x30 • 1.40 4H .12 9 1.25 B 46 48 4.25 D 27x40 3.50 6H .12 12 1.40 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. 203 No. 4254. No. 4249C-D. No. 4260. No. 4264. 4246. 4248. 4249. 4250. 42.12. 42.14. 42.1(5. 4258. 4260. 4261. 4264. SCALE, Triangular, boxwood, one edge graduated for 12 inches in scales of ««,.., %, sHoi %, %, %, %, 1, 1% and 3 inches to the foot For STRAIGHT EDGE, see No. 12974. TRIANGLES, Celluloid. No Angles, degrees Longest side, inches Each TRIANGLES, Hard Rubber. No Angles, degrees Longest side, inches Each , TRIANGLES, Pearwood, framed. No Angles, degrees Longest side, inches Each T SQUARES, pearwood blade and head, fine quality Length, inches Each No. 4258. other edges have $0.50 A 30&60 6 .30 A 30&60 6 .20 A 30 & 60 6 .15 B 30&60 8 .45 B 30&60 8 .30 B 30&60 8 .18 24 .30 C 45 6 .45 C 45 6 .30 C 45 6 .18 30 .45 D 45 8 .60 45 8 .33 D 45 8 .25 36 .60 DRAW KNIFE, polished cast steel, razor blade, 8-inch 1.30 DRAW PLATE, of hardened steel, for drawing wire to smaller sizes. Numbers are not standard gauge, but approximate those of the Starrett gauge. With holes numbered from 1 to 30. 4.00 DRILL, Breast, double gears, capacity of chuck 0 to %-inch, two speeds; adjustable breast plate: spindle runs in a hardened steel cone bearing 5.50 DRILL, Hand, single gear, length 10% inches, with 8 'steel drill points from i/j6 to i%4 inch; capacity of chuck 0 to %2 inch; holds either fluted or round shank drills. Frame all steel, pol- ished and nickel-plated 2,65 EXTRA DRILL POINTS for No. 4260, plain round shanks. May be used also with Nos. 4258, 4264 and 4270 Drills. In sets of eight, 1{6 to 1^4 inches Per set .70 DRILL, Hand, double gears, two speeds, capacity of chuck 0 to % inch; knurled nut; frame of malleable iron, japanned 4.65 204 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 4280. No. 4282. No. 4284. 4266. 4267. 4270. 4272. 4274. 4276. 4280. 4282. 4284. 3143. 3144. 4350. DRILL, Hand, Automatic, 9M> inches long, nickel-plated. Eight steel fluted shank drills, from YIQ to n/M inches, enclosed in the handle in numbered compartments. A very useful tool for boring holes in wood, bone, etc $2.00 EXTRA DRILL POINTS, fluted shank, as supplied with No. 4266. In sets of eight. .Per set .80 DRILL, Hand, Automatic, 11 inches long, nickel-plated, with wood handle. Capacity of chuck, 0 to y± inch round-shank drills. Without drill points 2.80 DRILLS, Twist, straight round shank, for wood or metal. Diameter, inches He V6 ^10 % ^16 % 7Ae % Each 14 .16 .20 .28 .36 .50 .72 1.00 DRILLS, Twist, straight round shank. Nos. 1 to 60, Stubs' steel wire gage, mounted on neat iron base which can also be used as a Stubs' Steel and Wire G-age. Indispensable for the labora- tory shop 9-45 DRILL GAGE. Stubs' steel gage Nos. 1 to 60 2.25 DRYING- APPARATUS, Bennert's, for organic analysis, consisting of four drying jars with sealed in tubes. Mounted on board as shown 13.50 DRYING- APPARATUS, Tauber's, with 2 U tubes and 4 jars with sealed in tubes. Mounted on board as shown 16.50 DRYING OVENS, soe Ovens, Drying. DRYING TUBE, Liebig's 40 DRYING TUBE, Vanier's, for zinc, as used in No. 3138 Vanier Combustion Apparatus 1.10 DRYING TUBE, Vanier's, for sulphuric acid, as used in No. 3138 Vanier Combustion Appar- atus 1-90 EBULLIOMETER, Salleron's, of polished copper with jacket around burner; for the rapid estimation of alcohol in wine, beer, etc. Complete in case with directions for use 60.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 205 Removable Coil System. No. F4453. ELECTRICAL INSTRUMENTS, ALL KINDS BATTERIES, Primary and Storage, see general heading Batteries. BELLS, Electric, see general heading Bells. CONDENSERS, Paper and Mica, see Catalog F of Physical Apparatus. DEMONSTRATION ELECTRICAL APPARATUS, see Catalog F of Physical Apparatus. ELECTROLYSIS OF WATER APPARATUS, see Lecture Apparatus. ELECTROLYTIC APPARATUS, see Xo. 5140. F3609. ELECTROMAGNET, 5 ohm resistance, for instrument making $1.00 ELECTROSCOPES, see Radioactivity Apparatus. ELECTROSTATIC APPARATUS, see Catalog F of Physical Apparatus. FURNACES, see general heading Furnaces. F4453. GALVANOMETER, D'Arsonval, Wall Form. This Galvanometer is a superior instrument, com- pact in design, and well finished in every detail. The Magnet is laminated, giving a strong, uniform and permanent field, which is concentrated by a soft iron core. The instrument is mounted on a finely finished hardwood board. Coil System. As noticed from the illustration, one of the principal features of this Galvanometer is its REMOVABLE COIL SYSTEM. The coil is suspended in a frame and forms with it a I'NIT which slides into place by means of guides into a good electrical contact. It is there- fore posible, by securing any number of coil systems, to have a universal instrument with only the additional' cost of the extra systems. Also, if any adjustments or repairs are to be made on the suspension system, the frame can be removed and laid flat on the table. Each Galvanometer is supplied with a 250 ohm DEAD BEAT Coil, with a plane mirror of %-ineh diameter. Extra Coils, Dead Beat and Ballistic, are listed below. The Suspension. The upper suspension, unless otherwise requested, is a steel ribbon (see No. F4515), which has a high tensile strength and a zero set of less than a millimeter. The sensi- bility can be much increased by the substitution of phosphor-bronze suspension. The Reading Device consists of a telescope with achromatic objective and a biekrome scale mounted upon an adjustable arm, which may be entirely removed when not in use. The Housing is of cast aluminum, combining strength with lightness, and is detachable by loosening two thumb screws, giving easy access to the interior. A large window is provided for viewing the moving system. Mounting and Leveling. The galvanometer is suspended on the wall by means of two suspension loops on the hardwood board which supports the magnet and housing. These loops are pro- vided with leveling screws and, with a third leveling screw in the center of the base board, provide a convenient means of leveling the instrument. Sensibility. From the mean of a number of readings the sensibility in megohms was found to be as follows: With dead beat coil of resistance, ohms 5 250 500 At working distance 3.5 33 48 At one meter distance 7.3 68 100 Complete with 250 ohm Dead Beat coil, and jeweler 'a screwdriver 35.00 206 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. F4473. No. F4475. F4454. F4456. GALVANOMETER, D'Ars'onval, Table Form. Same as No. F4453, but mounted on a heavy tripod for table use $37.50 COIL SYSTEMS, Dead Beat, for Nos. 4453-4. No. Resistance, ohms Each F4457. COIL SYSTEMS, Ballistic, for Nos. 4453-4. No Resistance, ohms Each A 5 7.50 B 250 7.50 C 500 8.00 ABC 150 500 1000 8.50 8.50 9.00 F4461. GALVANOMETER, Portable, Student's, 9 cm wide by 9 cm high, with inclined scale. With one volt a deflection of 1 millimeter (1 scale division) will be obtained through 62,500 ohms. Suitable for elementary Wheatstone Bridge work. Complete with zero adjusting device. 11.25 F4463. GALVANOMETER, Portable, D 'Arsonval Type, as used in commercial testing sets, and built for hard service. Gives 1 scale division deflection with 1 volt through about 100,000 ohms. 15.00 F4465. GALVANOMETER, Portable, D'Arsonval Type, as used in our No. F4749 Testing Set. Has a suspended coil system so that all troubles due to the dulling of the pivots as in the old style instruments is entirely obviated. Sensibility, 1 megohm, i. e., gives one scale division deflec- tion with one volt through 1,000,000 ohms. Mounted on a substantial hard rubber top in a finely finished hardwood case 50.00 GALVANOMETER ACCESSORIES F4473. UNIVERSAL SHUNT, Ayrton-Mather. This shunt may be used with any galvanometer, and therefore is far more useful than the ordinary type of shunt. The total resistance is 10,000 ohms, with shunt powers of 1, 5, 10, 50, 103, 500 and 1000. It is also fitted with a position in which the galvanometer is shorted through 10,000 ohms, and one in which both circuits are open All adjustments are made by turning a knob of hard rubber. Mounted in a fine ma- hogany case with hard rubber top 35.00 UNIVERSAL SHUNT, simpler design than No. F4473, but suitable for use with any galvano- meter, and therefore far more useful than the ordinary type of shunt. The total resistance is 5000 ohms, which is sufficiently high for use with any of the galvanometers listed in our catalogs. It is arranged for shunt powers of 1, 10, 100 and 1000, the different adjustments being made by use of a single plug. When the plug is at the zero position the main circuit is complete, but no current can flow through the galvanometer. Mounted in a brass case with wood base and hard rubber top 20.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 207 No. F4481. No. 4694. F4481. D'ARSONVAL KEPAIR KIT. Consists of a neat wooden box containing two pairs of forceps for handling suspensions, a watchmaker's screw driver, suitable for small screws on any gal- vanometer, 6 upper steel suspensions (see Xo. F4515) and 3 lower copper suspensions (Xo. F4483), all conveniently accessible. For use with No. F4453 Galvanometer $3.00 F4482. D'ARSONVAL REPAIR KIT. Same as No. F4481, with phosphor bronze (see No. F4511) in- stead of steel upper suspension 3.00 F4483. LOWER SUSPENSION only, copper, spiral form, as used on No. F4453 Galvanometer 20 F4491. GALVANOMETER MIRROR, plane, % inch diameter 35 F4492. GALVANOMETER MIRROR, plane, % inch diameter 60 F4493. GALVANOMETER MIRROR, concave, 1 meter focus, % inch diameter 1.50 F4494. GALVANOMETER MIRROR, concave, 2 meter focus, »/£ inch diameter 1.50 F4511. GALVANOMETER SUSPENSION RIBBON, Phosphor Bronze, 0.001x0.013 inches.. Per foot .10 F4512. GALVANOMETER SUSPENSION RIBBON, Phosphor Bronze, 0.0007x0.005 inehes.Per foot .10 F451o. GALVANOMETER SUSPENSION RIBBON, Steel, 0.0013x0.004 inches Per foot .10 GENERATORS 4694. GENERATORS, Dynamos, Shunt Wound, 110 volt. The following General Electric Dynamos are adaptable for all kinds of electrical lighting purposes, charging batteries, etc., etc., and are guaranteed to be free from mechanical or electrical defects. The Dynamos are of approved bi-polar construction, of the inter-pole or regulating-pole. type, insuring perfect commutation. The prices include the Dynamos complete with Field Bheostat, Sliding Base and Standard Pulley. No A B Power, kilowatts % % No. of 25 watt lamps Speed, r. p. m Diameter of pulley, inches Width of pulley face, inches Shipping weight, Ibs. Each . No Power, kilowatts No. of 25 watt lamps Speed, r. p. m Diameter of pulley, inches. . . Width of pulley face, inches. Shipping weight, Ibs Each . 20 2500 3% 2 100 143.45 25 1150 4% 3 185 210.40 30 2500 4% F 1% 73 2500 4% O 170 207.90 80 1150 4% 4 390 376.70 120 153.75 H 2Yi 90 1700 4% 3 270 344.75 D 1 40 2500 4% 2 130 178.60 J 3 120 1700 4^2 4 390 376.70 E 1 40 1700 4% 170 202.10 K 5% 220 1700 5% 4 540 471.20 For DEMONSTRATION DYNAMOS, see Catalog E. 208 CENTRAL SCIENTIFIC CO., CHICAGO, V. 8. A. No. 4704. No. 4708. No. F3665. No. F3681. 4704. GENERATOR, Electric Charging Dynamo, for charging storage batteries. Similar to No. 4708, but larger, weighing 23 Ibs. Generates 7 volts, 11 amperes, at 2000 r. p. m $25.00 4706. GENERATOR, Electric Plating Dynamo. Similar to No. 4704, but wound for 4 volts, 15 am- peres 25.00 4708. GENERATOR, Experimental Dynamo. A shunt-wound dynamo particularly desirable for experi- mental purposes. It will light to full power twelve 6 volt 3 C. P. lamps. The field is of the ring type, cast solid with the frame. The coils are form wound, carefully taped and shellacked; they are entirely safe from mechanical injury or breakdown. The armature is of the drum type, laminated, slot wound — it does not heat. The commutator is of hard copper, carefully insulated with mica. The brush holders are of new design, of the radial type, mounted on an adjustable yoke. The brushes are of woven wire, self-adjusting — they do not spark. The bearings are of hard bronze, nicely fitted; workmanship throughout the best. Finished in black enamel. Fitted with 1^-inch grooved pulley. Length of shaft, 6 inches. Weight, 9 pounds. Occupies space 6x4%x6 inches. At speed of 2200 r. p. m., the output is 36 Watts (6 volts, 6 amperes) 12.50 HOT PLATES, see general heading Hot Plates. F3681. INDUCTION COIL, with adjustable vibrator or interrupter, commutator and condenser, wound with insulated wire. (The coils ordinarily sold are French coils wound with bare wire.) Mounted on finely polished mahogany box. No A B C D Spark length, mm 6 13 18 25 Each i 5.00 9.00 12.00 15.00 F3665. INDUCTION COIL, equipped with a patented mechanical circuit breaker, which is mounted in- dependently on a heavy piece of enameled slate. This makes the construction very rigid and increases the efficiency of the coil. The secondaries are built in sections and each section is wound in layers. Three special means of adjustment are provided, allowing a wide range of regulation, so that the coil is adapted for a large variety of work. Complete with a double pole, double throw knife switch. The 150 mm coil will produce a heavy 150 mm spark with an input of 4 volts, 6 amperes (24 watts) ; the other coils take a proportional input. No A B C Spark length, mm 50 75 150 Each 30.00 40.00 75.00 LAMPS, Incandescent, see general heading Lamps. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 209 No. 4496. No. 4512. METERS, POCKET D. C. These meters are of the permanent magnet type and are extensively used for rapidly measuring the polarity, voltage and amperage of batteries. They are exceedingly dead beat, being made so by the relation of the moving system to the magnetic field and not by friction or air vanes, as in other types. Each instrument is packed in a chamois bag. 4492. AMMETER. Range 0-30 amperes $1.00 4494. VOLTMETER. Range 0-10 volts 1.00 4496. VOLT-AMMETER. Range 0-15 volts and 0-30 amperes 1.20 METERS, CENCO DIRECT CURRENT PORTABLE TYPE. A line of dependable electrical measuring instruments at a reasonable price. They are made on the D'Arsonval Galvanometer principle with a rectangular coil of wire rotating in a small annular gap be- tween a core and pole pieces. This gap is traversed by a concentrated uniform field produced by a powerful permanent laminated magnet. The current is carried into and out of the coil by means of non- magnetic springs. The moving element is perfectly balanced between .two highly polished jewels. The throw of the coil is stopped by the coil striking its support. This prevents the bending of the pointer and the destroying of the calibration of the instrument. A large window directly over the moving system shows all of the working parts. The meter is enclosed in a dust proof finely finished metal case on a polished mahogany base. Leads are brought to three of our Cenco binding posts, which are recommended for their convenient size and from the fact that their construction will not allow the knurled nuts to be lost. Ammeters, voltmeters and volt-ammeters can be furnished in the ranges listed below. In each in- strument the calibration is guaranteed to 1 per cent, of the full scale. 4504. AMMETERS, Cenco. No A B C Range, amperes, zero to 1 10 25 Smallest division, amperes 0.01 0.1 0.2 Each 12.00 12.00 15.00 4506. AMMETER, Cenco, with double scale. Ranges, 0-12 amperes in 0.1 ampere divisions and 0-1.2 amperes in 0.01 ampere divisions. . . . .. $13.00 4508. VOLTMETERS, Cenco. No A B C D Range, volts, zero to 5 10 150 250 Smallest division, volts 0.05 0.1 1.0 2.0 Each 12.00 12.00 14.00 15.00 4510. VOLTMETER, Cenco, with double scale. Ranges, 0-150 volts in 1 volt divisions and 0-7.5 volts in 0.05 volt divisions 15.00 4512. VOLT-AMMETER, Cenco, combined instrument with ranges 0-10 volts and 0-10 amperes in 0.1 unit divisions 12.00 210 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Model 155. 4524. 4526. 4532. 4534. 4546. 4548. 4550. 4572. 4574. Model 156. METERS, IMPERIAL— ALTERNATING CURRENT. METERS, SWITCHBOARD. Standard electromagnet construction, hand calibrated scales, which, as iu all A. C. Meters, cannot be used with great accuracy over the first 20 or 25 per cent of their range. Best quality jewel and pivot bearings; brass case, finished in baked enamel and dust proof. Diameter, 4 inches. AMMETEBS. No Eange, amperes Smallest division, amperes Each VOLTMETERS. A 1 0.02 $9.50 B 3 0.05 9.50 C 5 0.1 9.50 D 10 0.2 10.35 E 15 0.25 10.35 F 30 0.5 10.65 No Range, volts Smallest division, volts. Each . A 10 0.2 9.50 B 15 0.25 9.80 C 30 0.5 9.80 D 50 1 10.35 E 150 2.5 11.50 F 250 5 12.65 METERS, WESTON— ALTERNATING CURRENT. METERS, PORTABLE, Model 155. These instruments are perfectly dead beat, extremely sensi- tive and quickly and accurately respond to the most minute as well as to the greatest fluctua- tions in current strength, or in potential difference. They may be used on circuits of any frequency, within the limits of engineering practice of today, without sensible error in their indications. Provided with hardened steel pivots, jeweled bearings and mounted in neatly finished dust-proof wood cases. Dimensions 7x714x3% inches. AMMETER, 0-10 amperes $21.25 4538. VOLTMETER, 0-75 volts 23.15 AMMETER, 0-25 amperes 21.25 4540. VOLTMETER, 0-125 volts 23.15 METERS, SWITCHBOARD, Model 156. These instruments are of a high standard of excellence, indicate the same whether left in circuit for a minute or permanently, may be used on circuits of any ordinary frequency, are entirely dead beat, and are provided with a remarkably uniform scale. Diameter of case, 7.25 inches; depth of case, 3.15 inches. AMMETER, 0-10 amperes 16.90 AMMETER, 0-25 amperes 16.90 4554. VOLTMETER, 0-75 volts 18.15 AMMETER, 0-50 amperes 17.20 4556. VOLTMETER, 0-130 volts 18.15 BOTH ALTERNATING AND DIRECT CURRENT. AMMETERS, PORTABLE, Model 370. Instruments are of the electro-dynamometer type, which may be used either on direct current circuits or on alternating current circuits of any frequency up to 133 cycles per second. Contained in polished mahogany boxes, 8x10*4x5% in., with carry- ing handles, locks and covers. (See illustration on page 211.) The scales are 5% in. long and are of necessity not uniform so that they cannot be used with great accuracy over the first 20 or 25% of their range, e. g., the 10 ampere scale is graduated in tenths from 2 to 10 amperes and this range covers 5 in. of the length of the scale. Parallax is prevented by use of mirror scale plates and knife edge pointers; the entire coil system is mounted in a double closed iron shield; the pointer responds very quickly to changes in the applied current; the instruments are not affected by ordinary changes in external temperature and are free from working errors; and an accuracy of 14 of 1 per cent, of the full scale value is guaranteed on the working part of the scale. For both Alternating and Direct Current. MILLIAMMETERS, single range. No A B C D Range, mil-amperes 50 100 500 750 Approx. resistance, ohms 167 26.5 1.2 0.9 Each $84.40 84.40 84.40 84.40 AMMETERS, double range. No Ranges, amperes Each A 2-1 93.75 B 5-2.5 93.75 C 10-5 93.75 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 211 Model 370. (See page 210.) Model 341. Model 310. METERS, WESTON— (CONTINUED). VOLTMETERS, PORTABLE, Model 341. Those instruments are of the same general description as the Model 370 Ammeters described on page 210. For ordinary measurements, no temperature corrections are necessary. These instruments may be left in circuit continuously, but all ranges above 5 volts are provided with locking contact keys by means of which the circuit may be opened. The 1, 1.5 and 5 volt ranges have a small working error, but on the higher range in- struments the working error is inappreciable. For both Alternating and Direct Current. 4576. VOLTMETERS, single range. No A B C D E F Range, volts 1 5 10 30 120 300 Approx. resistance, ohms 2 18 66 470 2700 6700 Each $81.25 81.25 78.15 75.00 75.00 78.15 4578. VOLTMETERS, double range. No A B C Ranges, volts 15-1.5 120-60 300-150 Approx. resistance, ohms 30-3 2700-1350 6700-3350 Each 87.50 81.25 84.40 WATTMETERS, PORTABLE SINGLE-PHASE, Model 310. These instruments represent the latest development in electro-dynamometer wattmeters and have the same general description as the Model 370 Ammeter described on page 210. The field coils are designed to stand double their normal capacity continuously, and the potential circuits a voltage of 1% times their normal value. A reversing switch is provided by.means of which the direction of the current through the movable coil may be changed without changing the direction through the rest of the poten- tial circuit. This makes it possible to obtain a positive deflection without changing connec- tions. The scales are uniform throughout their entire length. For both Alternating and Direct Current. 4584. WATTMETERS, Single-phase, double voltage and current ranges, volts, but will stand 300 and 150 volts without any damage. Rated voltages of 200 and 100 No A B C D G Normal amperes, series 1 2.5 5 10 20 30 50 Normal amperes, multiple 2 10 20 40 60 100 Maximum amperes, series.... 2 5 10 20 40 60 75 Maximum amperes, multiple. . 4 10 20 40 80 120 150 Kilowatts, field coils in series 0.2 /O.l 0.5/0.25 1/0.5 2/1 4/2 6/3 10/5 Kilowatts, field eoils in mul- tiple 0.4/0.2 1/0.5 2/1 4/2 8/4 12/6 20/10 No. of scale lines 100 100 100 100 100 120 100 Each 93.75 93.75 93.75 93.75 100.00 100.00 100.00 WATTMETERS, PORTABLE POLYPHASE, Model 329. These instruments are of the same gen- eral design as the Model 310 Single-Phase Wattmeters, but are larger, the dimensions being 0%xlO%x8 1/16 in. Each instrument consists of two single-phase wattmeters, electrically inde- pendent, but having their movable coils mounted on a common shaft so thf.t they rotate together. 4586. WATTMETERS, Two-phase, double voltage and current ranges. Rated voltages of 200 and 100 volts, but will stand 300 and 150 volts without any damage. No. Normal amperes, series Normal amperes, multiple Maximum amperes, series Maximum amperes, multiple Kilowatts, field coils in series. . . Kilowatts, field coils in multiple. No. of scale lines Each A 1 2 2 4 0.6/0.3 1.2/0.6 120 143.75 B 2.5 5 5 10 1.5/0.75 3/1.5 150 143.75 C 5 10 10 20 3/1.5 6/3 150 143.75 D 10 20 20 40 6/3 12/6 120 150.00 212 OENTEAL SCIENTIFIC CO., CHICAGO, IT. 8. A. Model 1. Model 45. METERS, WESTON —(CONTINUED). DIRECT CURRENT. METERS, PORTABLE, Model 45. These instruments are of sufficient accuracy for station -work and general testing. The movement is completely enclosed in an iron case (which protects it from stray magnetic fields), securely fastened in a wooden carrying box. This box is provided with a hinge cover which protects the scale and binding posts. Kos. 4602-6 Meters are provided with self-contained shunt. No. 4608 Meter has an. external shunt. 4600. MILLIAMMETER, range 0-100 ma. in 1.0 ma. divisions $31.25 4602. AMMETER, range 0-5 amperes in 0.05 ampere divisions 31.25 4604. AMMETER, range 0-15 amperes in 0.1 ampere divisions 31.25 4606. AMMETER, range 0-25 amperes in 0.2 ampere divisions 31.25 4608. AMMETER, range 0-50 amperes in 0.5 ampere divisions 31.90 4610. MILLIVOLTMETER, range 0-50 mv. in 0.5 mv. divisions 31.25 4612. VOLTMETER, range 0-5 volts in 0.05 volt divisions 31.25 4614. VOLTMETER, range 0-15 volts in 0.1 volt divisions 31.25 4616. VOLTMETER, range 0-150 volts in 1.0 volt divisions 36.90 NOTE. — Double Scale Voltmeters of the above- type will be furnished at a price of $6.25 in addi- tion to the price of the highest range. METERS, PORTABLE, STANDARD, Model 1. These meters are adjusted and calibrated with the greatest care, and when used properly give exceedingly accurate results. They are direct read- ing, portable, permanent, and ' ' dead beat, ' ' and are, in fact, the recognized standard instru- ments for laboratory and general testing. 4626. AMMETER, range 15 amperes, in 0.1 ampere divisions, readable to 0.01 ampere 65.00 4628. AMMETER, range 25 amperes, in 0.25 ampere divisions, readable to 0.025 ampere 65.00 4630. AMMETER, range 50 amperes, in 0.5 ampere divisions, readable to 0.05 ampere 65.00 4632. MILLIVOLTMETER, range 0-20 mv. in 0.2 mv. divisions, readable to 0.02 mv 50.00 4634. MILLIVOLTMETER, zero center, range 10-0-10 mv. in 0.2 mv. divisions, readable to 0.02 mv. 50.00 4636. MILLIVOLTMETER, zero center, double range 10-0-10 and 100-0-100 mv. supplied with key by which either range may be employed 55.00 Any of the above MILLIVOLTMETERS may be supplied with Shunts for ampere readings at an additional cost of 5.00 4638. VOLTMETER, range 150 volts in 1 volt divisions, readable to 0.1 volt 55.00 4640. VOLTMETER, double range, 150 volts readable to 0.1 volt and 15 volts readable to 0.01 volts. 75.00 4642. VOLTMETER, same as No. 4640, but with Reversing Key 77.50 METERS, SWITCHBOARD, Model 24. These small round pattern meters are expressly designed to meet the demand for good but law price instruments for use on switchboards. The total diameter of the front is 6% inches and the total depth 4 inches. They are carefully designed to secure the highest degree of durability and reliability; they are absolutely dead beat, and their indications can be relied upon within 1%. The cases are finished in black japan and are neat in appearance. 4652. AMMETER, 0-10 amperes in .2 ampere divisions 18.75 4654. AMMETER, 0-25 amperes in .5 ampere divisions 19.40 4656. AMMETER, 0-50 amperes in 1 ampere divisions 19.70 4658. VOLTMETER, 0-10 volts in .2 volt divisions 20.00 4660. VOLTMETER, 0-25 volts in .5 volt divisions 20.00 4662. VOLTMETER, 0-50 volts in 1 volt divisions 20.00 4664. VOLTMETER, 0-130 volts in 2 volt divisions 20.65 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 213 b No. 4671 (Vertical). 4674. No. 4674 (Horizontal). No. 4683. No. 4687. No. 4674. METERS, WESTON— (CONTINUED). METER, LECTURE TABLE, D. 0. GALVANO-VOLT-AMMETER. Combines six different electrical measuring instruments: (1) Galvanometer. (2) Milli- Voltmeter, range 25-0-25 mv. in 1 mv. divisions. (3) Mil- Ammeter, range 25-0-25 ma. in 1 ma, divisions. (4) Voltmeter, range 5-0-5 volts in 0.2 volt divisions. (5) Voltmeter, range 125-0-125 volts in 5 volt divisions. (6) Ammeter, range 25-0-25 amperes in 1 ampere divisions. The zero is in the center of the scale so that no time need be wasted in determining the positive terminal of a cir- cuit. It is so mounted that it may be used in either of THREE POSITIONS — vertical, horizontal, or inclined at a convenient angle. (These positions are shown in the illustrations above.) The working parts are fully exposed to view and all connections may readily be traced. It is an extremely sensitive instrument, and having no suspensions, mirrors or adjustments to get out of order, is always ready for use. Among many uses are the following: The MEASUREMENT OF VOLTAGE, AMPERAGE AND RESISTANCE OF BATTERIES; the DETERMINATION OF RESISTANCE, CONDUCTIVITY, etc., of the various metals; the MEASUREMENT OF THE THERMO-ELECTRIC EFFECTS of different metals; as a CUR- RENT INDICATOR IN WHEATSTONE BRIDGE WORK; and as a LECTURE TABLE GAL- VANOMETER $40.00 No. 4686. METERS, LECTURE TABLE, D. C. 4682. AMMETER, with zero at left of seal?, mounted vertically in a dust-proof case, for demonstration work. Very sensitive, and always ready for use. Range 0-1 ampere in 0.01 ampere divisions. ." ." '. 27.50 4683. EXTRA SHUNT, to make No. 4682 read 0 to 10 amperes in 0.1 ampere divisions 5.00 4686. VOLTMETER, same style and mounting as No. 4682. Range 0-4 volts in 0.05 volt divisions. " 27.50 4687. EXTRA COIL, to make No. 4686 read from 0 to 120 volts in 1.5 volt divisions 5.00 214 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 4716. Nos. 4730-1 (F-O). MOTORS 4716. MOTOR, Porter Battery No. 1. A standard article, perfect in every detail of design arid con- struction, and accurately made. Nicely finished in black enamel. 1/100 h. p., 1.5-3 volts, 1.5 amperes, 5500 r. p. m.; size, 3^x3 l/4,x3% inches; weight, 1% Ibs $4.00 4717. MOTOR, Porter Battery No. 2. Same as No. 4716, but 1/90 h. p., 3-5 volts, 2 amperes, 4000 r. p. m.; size, 3%x4x4% inches; weight, 2% Ibs 7.00 4720. MOTOR, Universal. This motor may be used on 110 volt either Alternating (60 cycle) or Direct Current. Will develop approximately 1/50 h. p., is efficient and will not heat up when oper- ating on either circuit. It is constructed in a substantial manner, having laminated fields and armature and a twelve-section copper commutator. It uses a ^g-inch carbon brush and is equipped with compression grease cups and bronze bearings which insure perfect lubrication. It weighs 4% pounds, is 5 inches high and consumes .about the same amount of current as one 8 candle power lamp 8.00 4724. BATTERY RHEOSTAT, for regulating the speed of small motors, and also for use with minia- ture battery lamps. This rheostat is nicely finished with nickel trimmings and rubber handle. Resistance, 0 to 5 ohms 1.40 MOTORS, Alternating Current, Single Phase, 60 Cycle. These General Electric A. C. Power Motors are of the Split Phase Induction Type for constant speed and continuous service. No ......................... H. P ....................... Speed, r. p. m .............. Diameter of pulley, inches... Width of pulley face, inches.. Shipping weight, Ibs ........ 4730. MOTORS, 110 volts ......... Each 4731. MOTORS, 220 volts ......... Each B D E 1725 1140 1725 1140 1725 1% 1% 1% 1% 1% Grooved for %-in. round belt. 24 27 27 28 28 25.85 26.95 26.95 28.05 26.95 28.05 30.80 31.90 30.80 31.90 1140 2% 1% 41 41.80 42.90 G V* 1725 2% 1% 41 41.80 42.90 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 215 No. 4736. No. 4746. No. 4756-7 (A-F). 4734. MOTORS, Alternating Current, Single Phase, 60 Cycle. These General Electric A. C. Power Motors are of the Repulsion Induction Type for constant speed and continuous service. They are so built that they may be used on either 110 volt or 220 volt current. This type of motor requires less starting current than the Split Phase Induction Type and its use is required by some central power stations. No A B C H. P % % % Speed, r. p. m 1725 1140 1725 Diameter of pulley, inches... 2 2% 2% Width of pulley face, inches.. Grooved 1 1 Shipping weight, Ibs ?.2 40 40 Each $39.60 52.80 50.60 D U 1140 3% 2 55 67.10 £ % 1725 3% 2 55 62.70 1140 3^ 2 80 80.30 1725 3% 2 80 79.20 4736. MOTORS, Alternating Current, Single Phase, 60 Cycle. These General Electric A. C. Power Motors are of the repulsion induction type especially adapted to loads requiring heavy starting torque and have the same high operating characteristics as a D. C. Compound Motor. They are pro- vided with sliding base as shown in illustration above. They can be used on either 110 or 220 Volt, 60 Cycle, Alternating Current. Xo. . ................... A B C D E H. P ................................. 1 1 1% 2 2 Speed, r. p. m ......................... 1890 1200 1800 1800 1200 Diameter of pulley, inches ............... 4% 4% 4^ 4% 4>A "Width of pulley face, inches ............ 222 Shipping weight, Ibs ................... 160 175 185 175 215 Each ................................. 102.30 123.20 117.70 134.20 166.10 4746. MOTORS. Alternating and Direct Current, General Electric. The application of small power notors in industrial and domestic lines has increased to such enormous extent that small motors, of exceptional quality and lightness, are now available at low prices. They are series wound for continuous service, and will not develop an excessive speed when the entire load is thrown off. The A. C. motors operate on 110 volts 60 cycles, and will also operate on 110 volt direct current. The D. C. motors will operate only on 110 volt direct current. Xo ............................ A B C D E F G H H.P .......................... %oo ^oo Moo Moo %o %o %» %s Current ...................... A.C. D.C. A.C. D.C. A.C. D.C. A.C. D.C. Speed, r. p. m .................. 2200 2200 2200 2200 1800 1800 1800 1800 Diam. of V-groove pulley, inches, % % % % 1% 1% 1% 1% Shipping weight, Ibs. ..' ........ 10 10 10 10 15 15 24 24 Each .......................... 11.30 11.55 12.65 12.65 15.15 15.70 18.70 19.00 MOTORS, Direct Current, General Electric. For constant speed and continuous service. Xos. A to D are shunt wound; the others eompo-_nd wound. E H No A B C D H.p Ho i^, V>o Mo M" % % % % % % Speed', r. p.m.. . 1140 1725 1140 1725 1140 1725 1140 1725 1140 1725 1140 Diam. of pulley, inches .'. 1M IVi las 1% 1% 1% 2% 2% 3% 3% 3% Width of pulley face, inches..'. Grooved for *4 -inch round belt. iy4 1>4 2 2 2. Shipping weight, Ibs 24 24 24 24 24 24 28 28 50 50 51 4756. MOTORS, 110 volts. Each 20.90 20.90 23.10 23.10 25.85 25.85 35.20 35.20 64.90 64.90 79.20 4757. MOTORS. 220 volts. Each 22.00 22.00 24.20 24.20 26.95 26.95 36.30 36.30 66.00 66.00 80.30 216 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 4760-1. No. 4814. No. 4816. 4760. 4761. 4772. 4773. 4776. 477/. 4810. 4814. 4816. No. 4810. Nos. 4772-4777. MOTORS, Direct Current, General Electric. These D. C. Power Motors are compound wound, con- stant speed, continuous service, Oil Ring Bearing Type, complete with no voltage release start- ing rheostat, sliding base and standard pulley of 4% -inch diameter and 2-inch face. No i A B C D E H. P % % I 1 2 Speed, r. p. m 1700 1150 1700 1150 1700 Shipping weight, Ibs 120 130 130 170 170 MOTORS, 110 volts Each $71.50 85.80 79.20 93.50 102.30 MOTORS, 220 volts Each 71.50 85.80 79.20 93.50 103.40 Series wound for 1800 r. p. m. at the rated H. P. Speed varies A Kp 12 14.40 15.00 B M2 14 14.40 15.00 Shunt wound, for 1800 r. p. m. Speed independent of load. ABC %o Vi2 % 12 14 17 14.40 14.40 17.00 15.00 15.00 18.50 MOTORS, Direct Current, Cenco. with load. No H. P Net weight, Ibs MOTOR, 110 volts MOTOR, 220 volts MOTORS, Direct Current, vCenco. No H. P Net weight, Ibs MOTOR, 110 volts MOTOR, 220 volts COUNTERSHAFT *4 inch in diameter and 12 inches long, with bearings and pulleys 1, 2, 3 and 4 inches in diameter. The pulleys are bored and grooves turned true with the shaft, to which they are fastened with set screws, so that their position on the shaft may be changed. Used in connecting small engines and motors with other machinery 2.40 SPEED REDUCING GEAR. An improved device by which the high speed of an engine or motor is converted into a slow, powerful motion. The round plate may be removed, if desired, and direct connection made to shaft. Geared 48 to 1. Pulleys grooved for %.>-inch round belt. The fast running pulley has diameters 2, 3 and 4 inches, and the slow running pulley diameters 2 and 4 inches, thus giving a wide range of speeds 7.20 SPEED REDUCING GEAR. Similar to No. 4814, but with the gear enclosed in a case which la filled with grease so that the gear will run silently and without attention for a long time. Geared 48 to 1. Pulleys grooved for %2-inch round belt. The fast running pulley is 4 inches in diameter and the slow running pulley has diameters 1, 1%, 2 and 2% inches, thus giving a wide range of speed 10.80 For other MOTORS in addition to those listeJ, see Nos. 2361, 2362, 2398 and 2399. CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. 217 Nos. 4824-4837. MOTOR GENERATORS A. C. to D. C. DIBECT CURRENT NOW AVAILABLE WHEREVER THERE ARE ALTERNATING CURRENT MAINS. FEATURES. Generator shunt wound. Generator and Motor armatures mounted on same shaft. Motor has revolving primary and is well ven- tilated. Radial brushes set on neutral. Cartridge type brushholders used. No sub-base required. Sets may be bolted direct to support. Use of two-bearing construction makes set compact and efficient. Generous size bearings equipped with ring oilers. Heavy four arm bearing flanges with ample ventilating duets. Four thru bolts hold parts firmly together. The voltage chosen may be varied 25% above and below normal rating by means of the Field Rheostat furnished with each set. No starting box needed. Useful for Battery Charging. MOTOR GENERATORS, A. C. to D. C. "With single phase, 60-cycle Motor, and Generator wound for 6, 12, 18 or 24 volts D. C. (State voltage desired when ordering.) No A B C D Output, watts 50 100 175 250 Shipping weight, Ibs 49 69 90 155 4824. MOTOR GENERATORS, with 110 volt motor $59.40 68.20 85.80 137.50 4825. MOTOR GENERATORS, with 220 volt motor 60.50 69.30 86.90 138.60 MOTOR GENERATORS, A. C. to D. C. With single phase, 60-cycle Motor, and Generator wound for 60, 125 or 250 volts D. C. . (State voltage desired when ordering.) No A B C D E Output, watts 100 175 250 375 500 Shipping weight, Ibs 69 90 155 160 165 4828. MOTOR GENERATORS, with 110 volt motor. 62.70 82.50 123.20 155.10 172.70 4829. MOTOR GENERATORS, with 220 volt motor. 63.80 83.60 124.30 156.20 173.80 NOTE: Motors for other frequencies may be obtained at a slight advance in price. D. C. to D. C. Sets with the same features as those described above are listed for service on 110 or 220 volts Direct Current. MOTOR GENERATORS, D. C. to D. C. With direct current Motor, shunt wound, and Generator wound for 6, 12, 18 or 24 volts D. C. (State voltage desired when ordering.) 4832. 4833. 4836. 4837. No. Output, watts Shipping weight, Ibs MOTOR GENERATORS, with 110 volt motor. MOTOR GENERATORS, with 220 volt motor. A 50 49 50.60 51.70 B 100 69 61.60 62.70 C 175 90 80.30 81.40 D 250 155 132.00 133.10 MOTOR GENERATORS, D. C. to D. C. With direct current Motor, shunt wound, and Generator wound for 60, 125 or 250 volts D. C. (State voltage desired when ordering.) No A B C D E Output, watts 100 175 250 375 500 Shipping weight, Ibs 69 90 loo 160 165 MOTOR GENERATORS, with 110 volt motor. 57.20 75.90 117.70 146.30 167.20 MOTOR GENERATORS, with 220 volt motor. 58.30 77.00 118.80 147.40 168.30 For MOTOR GENERATORS with Switchboard see next page. 218 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Nos. 4842-4848. MOTOR GENEEATOES with Switchboard. These motor generators will meet the demand for a self contained outfit for the laboratory, which may be used to furnish the regular laboratory current and is especially valuable for battery charging. The outfits consist of a Motor Generator Set of the type described on page 217, with the generator for from 24 to 72 volts D. C., depend- ing on the output, and a steel switchboard panel, mounted as in the illustration and having the following FEATUEES. Voltmeter for reading voltage. Push button to be pushed when reading voltmeter. Snap switch for closing and opening battery circuit. Ammeter for reading charging current. Rheostat for adjusting charging current. Snap switch in line circuit for starting and stopping. Field rheostat for adjusting voltage. The field rheostat will reduce the voltage of any set to 25 per cent of its normal rating, but the charging rate used must not exceed the ampere rating marked on the generator name*plate. No A B C D E Output, watts 175 250 375 500 750 Voltage of generator 24 24 36 48 72 Shipping weight, Ibs 105 170 175 180 200 4842. MOTOE GENEEATOES, with 110 volt, A. C., single phase, 60-cycle motor $115.50 169.40 201.30 218.90 255.20 4844. MOTOE GENEEATOES, with 220 volt, A. C., single phase, 60-cycle motor 116.60 170.50 202.40 220.00 256T30 4846. MOTOE GENEEATOES, with 110 volt, D. C., shunt wound motor 111.10 160.60 193.60 213.40 4848. MOTOE GENEEATOES, with 220 volt, D. C., shunt wound motor . 112.20 161.70 194.70 214.50 NOTE: Nos. 4842-4 B, C, D and E can be furnished with three-phase motors for 5 per cent, more than the above prices. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 219 4867. 4868. 4870. No. 4866. OVENS, see general heading Ovens. RADIOACTIVITY APPARATUS, see general heading Radioactivity Apparatus. RECTIFIERS 4866. RECTIFIER, ELECTROLYTIC, or NODON VALVE. Consists of four cells with electrodes of lead and aluminum, and depends for its action on the fact that an electric current will not enter the electrolyte from the aluminum electrode, but will pass freely into the electrolyte from the lead. The electrodes are fastened to a substantial non-conducting top, with binding posts for both A. C. and D. C. circuits. The connections are made by straps of metal, so that the path of the current is readily traced. This valve, though not as satisfactory as a Motor Generator, may be used on either 110 or 220-volt alternating circuit with a moderately high efficiency. Currents of from 5 to 8 amperes may be obtained for laboratory use, and for short periods of time, much larger currents may be drawn from the valve. Complete with chemicals, glass jars, and full directions $19.00 CHEMICALS for No. 4866, per complete charge 50 GLASS JAR for Xo. 4866, for replacements 40 RECTIFIERS, TUNGAR. These rectifiers consist of a bulb filled with an inert gas at low pres- sure and having for cathode a filament of small tungsten wire coiled into a closely wound spiral and for anode a piece of graphite of relatively large cross section. The tungsten filament is heated to incandescence by being placed in the secondary circuit of a transformer, which is part of the outfit. This incandescent filament, as is well known, emits electrons and ionizes the rarified gas in the bulb, which thus becomes a conductor of electricity. In addition to be- ing in the secondary circuit of the transformer, the tungsten filament is connected to one ter- minal of the A. C. line and the graphite electrode to the other terminal. During the half -cycle in which the filament is negative, the electrons being themselves negative are driven from the filament and across to the graphite positive electrode, ionizing the gas molecules as men- tioned above and permitting the passage of a current. During the other half of the cycle when the filament is positive, if any electrons are emitted, they are immedi- ately attracted to the filament again, so that the gas remains non-conducting. Since the direc- tion of a current is opposite to the direction in which the negative electrons travel, it is evident that the current passes during each alternate half -cycle from the graphite electrode to the tung- sten filament through the bulb. We therefore have in the circuit of the bulb a pulsating uni- directional current. This current is especially adapted to battery charging but may be used for many other purposes such as in electrolytic experiments, electro-plating, for running small motors, etc. Tungar Rectifiers are designed for 115 volt, 60-cycle circuit, but may be used on from 105 to 125 volt circuit. They are mounted in a black japanned casing, with a perforated top. This cas- ing contains the bulb, the transformer and a fuse to protect against overloads. These rectifiers are especially superior to many rectifiers or the market in that they operate satisfactorily when only a fraction of their full output is being used. Nos. A and B are provided with legs for placing on floor or table; No. C is intended for wall installation, and is provided with ammeter. Furnished with cord and plug for attachment to any incandescent lamp socket. No. Output, full load, watts. . . . Amperes, full load Volts, full load Height, inches Depth, inches Width, inches Shipping weight, Ibs Each 4871. TUNGAR BULB only, renewal. A 15 2 7.5 8'4 5% 6% 12 16.00 3.00 B 90 6 15 10 8 6% 24 24.00 7.00 C 450 6 75 14 12% 81 115.00 8.00 220 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. No. F4701. No. F4703. RESISTANCE BOXES AND WHEATSTONE BRIDGES In the construction of our resistance boxes we use high grade rubber plates for the tops, of sufficient thickness to insure a firm anchorage for the brass bars, and the best obtainable wire. All coils are wound bifilar in uniform layers and are practically free from inductance and capacity so that any of the boxes may be used in conductivity experiments with alternating currents. The coils are securely fastened to the top, so that there is no danger of the spools breaking loose and destroying the connections. Our plugs are provided with knurled hard rubber tops moulded on, which prevents removal. The plugs are carefully fitted, giving good contacts, and are placed sufficiently far apart to insure easy manipulation. The brass blocks are heavy and separated so that the insulation between may be cleaned. We guarantee, without reservation, all our boxes to be accurate within the per cent, claimed, and any boxes will be replaced that show faulty construction or do not come up to the guaranteed accuracy when compared with reliable standards. F4701. RESISTANCE BOX, Spring Contact Design. The greatest objection to the plug form resistance box, when used by inexperienced workers, is the unreliability of the contacts, caused either by the loosening of the adjoining plugs when one is withdrawn or by a loose fit, caused either by exchange or failure to properly insert the plugs. As will be noticed in the above illustration, these dangers have been obviated by the use of the spring contact, which, on account of the taper, fits tightly all points of the plug, causing no irregular wear. The external resistance of the box has not been materially increased. The total resistance is 111 ohms, divided as follows: 0.1, 0.2, 0.3, 0.4, 1, 2, 3, 4, 10, 20, 30 and 40 ohms. The coils are guaranteed accurate to 1%. §10.00 F4703. RESISTANCE BOX, Standard Design, for individual student use. We believe this box will be found to be superior to any sold at an equal price. The total resistance is 111 ohms, divided as follows: 0.1, 0.2, 0.3, 0.4, 1, 2, 3, 4, 10, 20, 30 and 40 ohms. The coils are guaranteed accu- rate to % of 1%. For detailed description of construction, see above 12.00 F4704. RESISTANCE BOX, same as No. F4703, but with guaranteed accuracy, %% 15.00 F4705. RESISTANCE BOX, same as No. F4703, but with total resistance of 1,111 ohms, divided as fol- lows: 1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300, 400 ohms. Guaranteed accuracy, %% 17.50 F4711. RESISTANCE BOX, Standard Design, with traveling plugs. The blocks are of new and im- proved form, which enables the coils to be held more firmly in position, and lessens the danger of imperfect contact between coils and blocks. The traveling plugs add greatly to the useful- ness of the instrument, making it available for the comparison of the E. M. F. of batteries and other tests by the potentiometer method. The total resistance is 1,111 ohms, as follows: 0.1, 0.2, 0.3, 0.4, 1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300 and 400. For detailed description of con- struction see above. Guaranteed accuracy, %% 45.00 CENTRAL SCIENTIFIC CO., CHICAGO, IT. S. A. 221 NO. F4719. F4713. EESISTANCE BOX, same as No. F4711, but with total resistance 11,110 ohms, as follows: 1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300, 400, 1000, 2000, 3000 and 4000 $45.00 F4719. RESISTANCE BOX, Dial Decade Design. A 3-dial resistance box having a total resistance of 1110 ( = 10x1 + 10x10+10x100) ohms, mounted in a mahogany finished hardwood box, with hard rubber top about. 15x40 cm. Contact with the blocks at the end of the swinging arm is made by a multiple brush with ends bent so that they are not tangent to the circle in which they move and therefore do not wear rings in the blocks. The coils are of the same descrip- tion as those used in our other resistance boxes (see page 220), and are guaranteed to % of 1% 45.00 RESISTANCE BOXES, Dial Decade Design. High grade hard rubber top, mounted in a wood case, or, if preferred, in a perforated metal case so that the coils may cool rapidly or be im- mersed in oil to give extra large current carrying capacityi The dials may be rotated in either direction continuously, the dial switches make thoroughly reliable contact and the brushes are set so that they do not wear rings in the blocks. Guaranteed accuracy 1/10 per cent. No A No. of dials 3 Smallest resistance, ohms 10 Total resistance, ohms 11,100 F4721. EESISTANCE BOXES, in wood case $80.65 F4722. EESISTANCE BOXES, in metal case 80.65 B C D 4 4 5 0.1 1 0.1 1,111 11,110 11,111 106.25 106.25 125.00 106.25 106.25 125.00 222 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. F4733. No. F4731. F4725. MEGOHM BOX, Standard, with five groups of coils of 200,000 ohms each. Six pillars, well in- sulated, are used on a hard rubber top, there being 200,000 ohms between each pair of pillars. There is a double contact post on top of each pillar, so that these can be connected together with copper links. In finely finished hardwood box $187.50 F4727. TENTH-MEGOHM BOX, Standard. In four units of 10,000, 20,000, 20,000 and 50,000 ohms. An infinity plug separates each coil from the one next to it. Segments are insulated by hard rub- ber above the hard rubber top in order to increase the insulation. In finely finished hardwoo:! box 62.50 WHEATSTONE BRIDGES AND POTENTIOMETERS F4731. RESISTANCE BOX and WHEATSTONE BRIDGE Combined. Polished hardwood mahogany finished box with hard rubber top %-inch thick. Heavy brass blocks of new design (see No. F4711) are used. For other details of construction, see page 220. The bridge coils are six in number, 1, K) and 100 ohms on each side. The rheostat coils are twelve in number, viz: 1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300, 400 ohms. The total range of measurement is therefore from 0.01 to 111,000 ohms. The binding posts for battery, galvanometer, and unknown, and keys with platinum contacts for battery and galvanometer are conveniently placed, and all hidden connections are clearly indicated by lines on the top of the box. Guaranteed accuracy, %%. 40.00 F4733. RESISTANCE BOX and WHEATSTONE BRIDGE Combined. An exceptionally high grade box of the finest materials and first class workmanship. The blocks are of new and improved de- sign (see No. F4711), and the other details of construction are as described on page 220. The rheostat coils are sixteen in number, viz: 1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300, 400, 1000, 2000, 3000, 4000 ohms. The bridge coils are eight in number, 1, 10, 100 and 1000 ohms on each side. The total range of measurement is therefore from 0.001 to 11,110,000 ohms. The binding posts for battery, galvanometer, and unknown, and keys with platinum contacts for battery and galvanometer are conveniently placed, and all hidden connections are clearly indicated by lines on the top of the box. Has two traveling plugs. Guaranteed accuracy, 1/io% • • • • 55-00 F4739. BRASS PLUG, with knurled rubber top, as used on our Resistance Boxes 26 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A No. F4853. No. F4749. DIAL WHEATSTONE BRIDGES. No- F4741. WHEATSTONE BRIDGE, Dial Decade Design. Similar in construction to Nos. F4721 Dial Re- sistance Boxes listed on page 221. Has six ratio coils, one each 1, 10, 100, 100, 1,000 and 10,000 ohms, adjusted to an accuracy of 1/25 per cent. The rheostat has four dials, giving 10x1, 10x10, 10x100 and 10x1,000 ohms, a total of 11,110 ohms, and is adjusted to an accuracy of 1/10 per cent $131.25 F4742. WHEATSTONE BRIDGE. Same as No. F4741, but with ten ratio coils, two each 1, 10, 100, 1,000 and 10,000 ohms 137.50 F4743. WHEATSTONE BRIDGE. Same as No. F4741, but with five dial rheostat, giving 10x0.1, 10x1, 10x10, 10x100 and 10x1,000 ohms, a total of 11,111 ohms 150.00 F4744. WHEATSTONE BRIDGE. Same as No. F4742, but with five dial rheostat, giving 10x0.1, 10x1, 10x10, 10x100 and 10x1,000 ohms, a total of 11,111 ohms 156.25 F4749. TESTING SET, Portable. A compact and reliable self-contained instrument, including Wheat- stone bridge with rheostat, galvanometer, battery and necessary switches. The ratio arms of the Wheatstone bridge are of the plug type and include four coils in each arm, 1, 10, 100 and 1,000 ohms. The rheostat is of the dial decade type with four dials, units, 10 's, 100 's and 1,000 's, giving a total resistance of 11,110 ohms. The rheostat switches may be revolved continuously in either direction and the contacts are made by multiple brushes, with ends bent so that they are not tangent to the circle in which they move and therefore do not wear rings in the blocks. The contact blocks are on the under side of the plate on which they are mounted, thus insuring a good contact, free from dirt. The galvanometer is of the suspended type and has a sensibility of 1 megohm. With a galvanometer of this type, all trouble experi- enced on account of the dulling of the pivots as used in old style instruments is entirely obvi- ated. The resistances are the same as used in our Resistance Boxes, described on pages 220-2, and are accurate to 1/10 per cent. The entire set is mounted in a finely finished hardwood case, with leather strap handle for carrying. Complete with directions 200.00 F4851. RESISTANCES on Spools. These resistances are of the same quality used in our Resistance Boxes and are guaranteed to be of the best workmanship. The winding is bifilar on substantial wooden spools, the ends soldered to heavy copper terminals. Accurate to i/£ of 1%. Resistance in ohms 1 2 5 10 25 50 100 200 500 1000 5000 Each 75 .75 .75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 3.00 F4853. RESISTANCE COILS, mounted in brass case, rubber top, with two binding posts and rubber top brass taper plug for short circuiting the coil. Coils wound bifilar on wooden spools, and guar- anteed to an accuracv of I/^Q of 1%. Resistance in ohms! 1 2 5 10 25 50 100 200 500 1000 5000 Each 6.00 6.00 .00 6.00 6.50 7.00 7.50 8.00 8.50 9.00 10.00 F4861. STANDARD RESISTANCES, N. B. S., as designed by Dr. E. B. Rosa of the Bureau of Standards. (Bulletin B. of Stds., Vol. 5, p. 413.) In these resistances the coil is wound on a metal cylinder and baked in shellac. It is supported by a small tube (closed at the bottom) which serves as a thermometer tube. The leads pass through a hard rubber top which screws into the brass case. The coil is adjusted to the highest precision and the case filled with moisture-free oil and hermetically sealed. These coils have the following advantages over the old Reichsanstalt form: — -(1) They are prac- tically constant. Only one coil out of 28 changed as much as 2 parts in 100,000 in 12 months. (2) They are more compact, the distance between terminals being only 7.5 cm. Resistance, ohms 1 10 100 1 .000 10.000 Each 20.00 20.00 20.00 20.00 25.00 224 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. No. 4960. No. 4964-8. No. 4990F. Nos. 4990B-E. No. 4990A. RHEOSTATS 4960. RHEOSTAT, Carbon, for use in battery testing, calibrating electrical instruments, photometry, and any experiments in which a UNIFORM VARIATION of resistance is desired. Com- sists of 90 carbon plates 1% inches square and % inch thick, mounted between castings on a base of asbestos wood so that pressure can be placed on them by a screw, thus allowing a range of resistance of from about 0.1 ohm to 8 ohms or more, including all intermediate values. Safe load for constant duty, 200 watts. A momentary overload of from 500 to 1000 watts may be applied without danger, of injury $15.00 RHEOSTATS, Ceuco Laboratory. These new rheostats embody all the excellent features of the rheostats of the Ruhstrat type which we formerly listed for Duty Free importation. Oxidized resistance wire is wound on an enameled metal tube which provides for the more rapid dissipa- tion of heat than the old slate form. The difference of potential between the adjacent turns is so small that the oxide covering of the wire provides sufficient insulation. The Current Eatings are for Continuous Duty. Each rheostat is provided with a slider for regulating the amount of resistance in circuit, and with three binding posts, as shown in the illustration, by means of which it may be used as either fixed or variable resistance or as a source of varying potential in a shunt circuit. Specify catalog number and size number in ordering. 4964. KHEOSTATS. Size of Tube, 2x8 in. No 1 2 4 6 8 Approx. resistance, ohms 1700 300 50 25 12 Current capacity, amperes 0.5 1 2 3 4 Each 7.50 7.50 7.50 7.50 7.50 16 3 8 7.50 4966. RHEOSTATS. Size of Tube, 2x12 in. No 1 2 3 4 5 Approx. resistance, ohms. . 3000 500 175 90 65 Current capacity, amperes. 0.5 1 1.5 2 2.5 Each 8.50 8.50 8.50 8.50 8.50 4968. RHEOSTATS. Size of Tube, 2x20 in. No 3 Approx. resistance, ohms 315 Current capacity, amperes 1.5 Each . 10.00 6 40 3 8.50 4 160 2 10.00 20 4 8.50 12 10 6 8.50 6 75 3 10.00 16 5 8 8.50 8 35 4 10.00 4990. RHEOSTATS, National, tapered (i. e., having the first step of greater current-carrying capacity than the others). These are inexpensive, variable rheostats for use in the laboratory where small current carrying capacities, comparatively small resistances and small wattage consump- tion are needed. (For rheostats of large resistance, high current capacity and maximum dis- sipation of energy, see Nos. 4964-4980.) A rolling contact insures long life to the resistance element. No A B C D E Maximum amperes, first step 1 5 Ampere capacity, with entire rheostat in circuit 0.5 1 1.5 2.5 Total resistance, ohms 80 40 26.6 20 16 No. of steps 228 250 238 252 252 Each 4.35 4.35 4.35 4.35 6.00 F 6 3 13.3 140 7.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 225 Nos. 4972-8. RHEOSTATS, Dodge Design, providing a system of wiring whereby a Cenco Rheostat may be con- nected either in series with the load or as a shunt across the line, the change being made simply by closing a single-throw switch. By means of the slider, the resistance may be varied from zero to the maximum of the rheostat. When connected in series with the load, this variation of the resistances produces a variation in the voltage across the load, the minimum of which is limited by the ratio of the load resistance to the total resistance of the circuit. The current through the load is varied in the same proportion. By this connection it is impossible to obtain very small currents and voltages. By closing the switch and thereby shunting the rheostat across the line, a potentiometer effect is secured by means of which the voltage and current may be varied from zero to a maximum amount, which is the same as the minimum of the series connection. In this manner one secures the full value of the rheostat and in a simple fashion can run the entire range of voltage and current. OTHER ADVANTAGES OFFERED BY THE DODGE RHEOSTAT. 1 — Substantial mounting upon base of asbestos slate. 2 — Clear distinction between terminals of load and line. 3 — Rating of rheostat in maximum current and voltage stamped in plain figures on slider. 4 — High efficiency. Greatest possible current range for given voltage and size of tube. 5 — Easy selection of proper capacity. Voltage of source and maximum load current determine the particular rheostat to purchase. In ordering rheostats of the Dodge design it is necessary to consider only the available voltage and the maximum current required by the load. Those listed first under each catalog number are designed to give the very highest capacity possible within the limits imposed by voltage, length of tube, and a moderate temperature rise, and therefore have the lowest resistance. These rheostats should be ordered unless it is absolutely certain that a higher resistance is needed. For these cases the other sizes are provided, wound with smaller wire, and hence of smaller current carrying capacity. Current rating is for continuous service with moderate tem- perature rise. Overloads of 50 per cent, and more are permissible on intermittent service. 4972. RHEOSTATS, Dodge Design, Single. For a maximum voltage of 40. Length of tube, 12 inches. No 12 6 4 Maximum current, amperes 6 3 2 Approximate resistance, ohms 10 40 90 Each $12.50 12.50 12.50 4974. RHEOSTATS, Dodge Design, Single. For a maximum voltage of 110. Length of tube, 12 inches. No 5 4 3 Maximum current, amperes 2.5 2.0 1.5 Approximate resistance, ohms 65 90 175 Each 12.50 12.50 12.50 4976. RHEOSTATS, Dodge Design, Single. For maximum voltage of 110. Length of tube, 20 inches. No 8 6 Maximum current, amperes 4 3 Approximate resistance, ohms 35 75 Each 16.00 16.00 4978. RHEOSTATS, Dodge Design, Single. For a maximum voltage of 220. Length of tube, 20 inches. No 4 3 Maximum current, amperes 2 1.5 Approximate resistance, ohms 160 315 Each 16.00 16.00 4980. RHEOSTATS, Dodge Design, Double. Two tubes in parallel on one base. No A B C D Maximum voltage 40 110 110 220 Maximum current, amperes ." 12 5 8 4 Approximate resistance, ohms 32 17 80 Length of tube, inches 12 12 20 20 Each 22.00 22.00 27.50 27.50 226 CENTRAL SCIENTIFIC CO., CHICAGO, TT. 8. A. No. F3865A. No. F3867. 4994. RHEOSTATS, Plate Type, tapered (i. e., having the first step of greater current-carrying capa- city than the others). Of rugged construction, intended for permanent mounting upon wall or switchboard, for use in field regulation of motors or dynamos. They will find many other uses in the laboratory where a permanent rugged rheostat is needed, such as the control of cur- rent for electric combustion and muffle furnaces, control of direct current for electrolytic A B 1 2 0.5 1 150 75 26 26 1 1 8 8 Each ................................ $6.50 6.50 work, etc. No Maximum amperes, first step .......... Ampere capacity, with entire rheostat in circuit ............................. Total resistance, ohms ................. No. of steps .......................... No. of plates in parallel ............... Diameter of plates, inches 5002. ROTARY CONVERTERS, for changing direct to alternating current. No. A 110 160 70 125 47.00 C D 4 8 2 4 37.5 18.75 26 45 1 1 8 12 6.50 9.50 ent. Complete B 220 160 140 125 47.00 E F 16 20 8 10 9.25 7.5 120 120 2 2 15 15 27.00 27.00 with starting box C D 110 220 250 250 70 140 185 18i) 55.50 55.50 and regulating rheostat. D. C. volts D. C. watts, approx. A. C. volts, approx. . A. C. watts, approx. Each F3865. TRANSFORMERS, Laboratory. For use on 110 Volt A. C. Circuits to give alternating currents at from 2 to 28 volts, which will operate all classes of small electric apparatus (A. C. or D. C.), including induction coils, motors and small lamps. These transformers are indestructible, being enclosed in a steel shell, and operate on 100 to 125 volts, 60 cycles. The windings are embedded in an insulating compound making them imper- vious to moisture and cementing the entire winding into one solid block. They are equipped with a new voltage regulator, which eliminates the necessity of a rheostat for controlling the secondary voltages and permits of the voltage being varied in steps of two volts. Voltages 4, 6, 8, 10, 14 and 18 are obtained by connecting to binding posts on the transformer without the use of the voltage regulator and any of these six different voltages can be used simultaneously. Each transformer is furnished with plug and flexible attachment cord for connecting trans- former to line circuit, as well as secondary terminals on the secondary side, and bears a name plate giving complete enumeration of the various voltages obtainable from it. No .". . A B C Capacity, watts 75 100 150 Dimensions, inches 4Vix3%x3i4 5x4x3% 5%x5x4 Weight, Ibe 5 8 11 Each 4.00 5.50 7.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 5102. No. F3879B. No. 5100. No. 5106. No. 5110. Insert Member cf No. 5110. No. 5111. No. F3879D. F3867. TRANSFORMER, Laboratory. To meet the demand for a transformer of smaller capacity than those listed under No. F3865, there has been developed a transformer of the same general de- scription but smaller and having a voltage regulator giving eleven different voltages in steps of 2^ volts, starting at 2% and going up to 27^ volts. It is 3%x3x3 inches, weighs 3 pounds and is designed for an output of 50 watts $3.00 F3871. TRANSFORMERS, Step-up. These Transformers represent the highest type of construction, and are perfect in every detail. Constructed with a magnetic shunt control to protect them from all undue current surges. Designed to connect to any alternating current circuit. No imped- ance coil or other resistance necessary. Can be used for Wireless Work, Generation of Ozone, Testing Insulation, Electrostatic Separation, High Frequency Experiments, etc. For operation on voltages ranging between 100 and 125 A. C., 60 cycles. Current regulates as per table below. No A B " C D Kilowatts % % 1 2% Secondary voltage 10,000 10,000 20,000 20,000 Primary amperes 1 to 6 2 to 9 2% to 14 6 to 22 Heightj inches 9 10 14 18 Width, inches 4% 5 6 8 Length, inches 9 10 12 14 Weight, Ibs 28 31 46 60 Each 20.00 25.00 30.00 55.00 F3873. TRANSFORMER, Step-up, similar to No. F3871 but without the magnetic shunt; especially adapted to wireless work. Capacity, ^4 k.w.; secondary voltage, 8000; size, 9x4V>x6 inches; weight, 13 Ibs " 12.00 F3875. RESISTANCES, Non-inductive, for use with Nos. F3871-3 connected in shunt across the primary terminals for prevention of inductive kick-backs in the primary circuit Per pair 1.00 F3879. TRANSFORMERS, Bell Ringing. Designed for ringing bells and buzzers and operating annun- ciators, burglar-alarm systems and gas lighting systems. They are intended for connection directly to the 110-volt, 60-cycle A. C. mains, are absolutely fireproof and may be short circuited indefinitely without burning them out or impairing their efficiency. Dimensions, 15x10.5x11 cm. No ". A B C D Secondary voltage 6 6-14-20 6-12-18-24 10-25-35 Capacity, watts 60 60 100 100 Weight,' Ibs 7^ ?V> 9 9 Each 6.00 7.00 9.00 10.00 ELECTRICAL ACCESSORIES 5100. ATTACHING PLUG, f useless, Edison, black moulded material with separable cover (No. 51161. 35 5102. ATTACHING PLUG for multiple work, porcelain. One end fits any Edison receptacle or socket, and the other is provided with Edison socket for incandescent lamp. At the side is a separable plug (No. 5116) for attaching a lamp cord which will be in multiple with the lamp in the socket .75 5103. ATTACHING PLUG for series work. Same as No. 5102 except that the lamp cori will be con- nected in series with the lamp in the socket .75 228 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 5128 Shell. No. F3541. No. F3542. No. 5126. No. 5130. No. F3543. No. F3552. No. F3561. 5106. CUT-OUT, Standard Plug Fuse. Double pole, Edison sockets, slotted porcelain base, for 125 volts, 30 amperes. Without fuse plugs -33 5110. FUSE PLUG, Edison, renewable, will hold any No. 5111 Fuse Link. Fuses easily replaced in insert member. No A B C D E Carrying capacity, amperes 3 6 10 15 30 Each 50 .50 .50 .50 .50 5111. RENEWAL LINKS for No. 5110 Per 100 2.00 2.00 2.00 2.00 2.00 For FUSE WIRE see No. 14438. F3405. POLARITY INDICATOR. Indicates instantly the negative and positive poles when connected in circuit. Size, 2.5x9 cm. Nickel-plated shell which covers and protects the glass tube from injury. For voltages up to 50 $2.40 F3406. POLARITY INDICATOR. Same as No. F3405, but for voltages from 50 to 600 2.40 F3409. POLE-INDICATING PAPER. When two electrical leads, or terminals, are placed close together upon a piece of the moistened paper, the negative pole shows a red stain. In books of 25 strips, 7x1 cm Per book .10 For PUSH BUTTONS see Nos. 1198-1200. 5114. RECEPTACLE, to take No. 5116 Plug, for open wiring; porcelain 30 5116. PLUG, for No. 5114 Receptacle, with two finger contacts; black moulded material. Used also on Nos. 5100, 5102 and 5103 20 5118. RECEPTACLE, Key, for open wiring, Edison; porcelain base, brass shell 70 5120. RECEPTACLE, Keyless, for open wiring, Edison; porcelain 25 5122. RECEPTACLE, Mounted. No. 5120 Beceptacb mounted on a wood base 10x10 cm, with binding posts. Suitable for use with any Edison base incandescent lamp 1.25 5124. RECEPTACLE, Miniature, porcelain, for No. 8196 Lamps 09 5126. ROSETTE, fuseless, for open wiring, for 250 volts or less; porcelain . . '. 30 5128. SOCKET, key, Edison, brass, for use on lamp cord; may also be used on % inch I. P. size male thread. Of new design, having the two parts of the shell held together by a threaded brass ring, which is readily removed when the socket is to be rewired. (Illustration shows construction clearly) .50 5130. SOCKET, keyless, Edison, porcelain, with two finger contacts, for use with Nos. 5100, 5102, 5103 and 5114 in place of the separable cover .30 SPARK COILS, see Induction Coils. F3541. SWITCH, Knife, porcelain base, single pole, single throw, 25 amperes. Base about 3x8 cm. .35 F3542. SWITCH, Knife, porcelain base, single pole, double throw, 25 amperes. Base about 3.5x10 cm. .50 F3543. SWITCH, Knife, porcelain base, double pole, single throw, 25 amperes. Base about 5x6.5 cm . .55 F3544. SWITCH, Knife, porcelain base, double pole, double throw, 25 amperes. Base about 6.5x10 cm. .80 F3551. SWITCH, Rubber Base, 1 point, with binding post. Base about 5x7.5 cm 1.20 CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. 229 No. 5134. J> No. 5156. No. 5148. No. 5140C. F3552, F3553, F3561, F3562, F3.363 5132. .3134. 5136. 5140. 5148. 5150. 5156. SWITCH, Rubber Base, 2 point, with binding posts. Base about 5x7.5 em $1.30 SWITCH, Kubber Base, 4 point, with binding posts. Base about 7.5x7.5 cm 1-85 SWITCH, Wood Base, 1 point, about 6.5 cm in diameter 15 SWITCH, Wood Base, 2 point, about 6.5 cm in diameter 17 SWITCH, Wood Base, 4 point, about 6.5 cm in diameter 26 SWITCH, Push Through, for use on lamp cord, for 125 volts, 6 amperes or 250 volts, 3 amperes: black moulded material 60 SWITCH, Snap, double pole, slotted porcelain base, for 250 volts or less, 10 ampere current. Indi- cates whether current is on or off 1-00 TAPE, Insulating, cloth base, % inch wide, black, best quality; will not dry out. In quarter pound rolls Per roll .25 TELEPHONE APPARATUS, see Catalog F of Physical Apparatus. For other ELECTRICAL APPARATUS, see Physical Chemistry Apparatus. ELECTROLYTIC OUTFIT, Braun, for the quantitative separation of metals. Extensively used for determining copper by the rotating anode. A complete determination can be made by this method in less than half an hour. The apparatus is equipped with a motor mounted at one side to which a line shaft is attached, from which each unit is driven by a special fric- tion device enabling the operator to use one or more units at one time. The speed is regu- lated by a rheostat. A separate rheostat controls the current supplied to the individual units, each unit having an individual switch. Revolving anodes and gauze cathodes should be used. The ammeter, line shaft, bearings, switches, etc., are all enclosed in glass to pre- vent coming in contact with acid fumes. The lower portion of the cabinet is covered with aluminum and the binding posts are also made of this material. Direct Current is necessary and where Alternating Current only is obtainable a Motor-Gen- erator Set should be obtained. (See Xos. 4824 to 4848.) Complete with ammeter, rheostats for motor and units, and stands for breakers, with instruc- tions for mounting and operating. Without platinum electrodes. No A B C Number of units 2 4 6 Each 125.00 175.00 225.00 For PLATINUM ELECTRODES, see general heading Platinum Ware. ELECTROLYTIC SUPPORT, with glass rod mounted on japanned iron tripod base, ring for dish with three platinum contact points and clamp for anode. Binding posts are provided on both ring and clamp. Height of rod, 11% inches; diameter of ring, 2% inches.... 4.50 ELECTROLYTIC SUPPORT, same as Xo. 5148, but with two clamps with binding posts 4.50 ELECTRIC ROTATOR for Anodes, with motor, adjustable bracket, spindle with chuck for holding anode, and three step pulley. Complete with rheostat for controlling the speed No A B C D A.C. D.C. For volts 110 220 110 220 Each 27.50 31.50 27.50 31.50 230 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 5168. No. 5170. No. 5172. No. 5174. No. 5180. No. 5183. No. 5188. No. 5191. EMERGENCY KIT, see First Aid Cabinet. 5160. EMERY CLOTH, in sheets 9x11 inches. No 000 00 0 1 Per sheet $0.10 .10 .10 .15 Per quire 2.00 2.00 2.00 2.25 5162. EMERY PAPER, in sheets 9x11 inches. No 000 00 0 Per sheet .' .06 .06 .06 Per quire 1.20 1.20 1.20 5168. EUDIOMETERS, Bunsen's, with platinum electrodes. Capacity, cc 50 Graduated in, cc i/,0 Each 2.00 5170. EUDIOMETERS, Bunsen's, with platinum electrodes; graduated in mm. Length of graduation, mm 300 Each 2.20 EUDIOMETER, Hoffman's, see Lecture Apparatus. 5172. EUDIOMETERS, Mitscherlich's, with glass stop-cock and platinum electrodes. Capacity, cc 50 Graduated in, cc 1/5 Each 3.70 5174. EUDIOMETERS, Ure'S, U form, with platinum electrodes, 50 cc; graduated in i£ths .15 2.50 1 .06 1.20 100 2.80 500 2.80 100 1/5 4.20 3.00 EXTRACTION APPARATUS 5180. EXTRACTION APPARATUS, Bailey-Walker, consisting of a metal condenser, small glass flask of special shape, and a small glass siphon cup. This is one of the most compact forms of extrac- tion apparatus and can be used for any kind of work. The flask is light and can be accurately weighed and easily cleaned. Made according to the design of Bailey and Walker, of the Bureau of Chemistry, United States Department of Agriculture. (See Journal of Industrial & Engin- eering Chemistry, Vol. VI, No. 6, for June 1914, page 497) 5.00 5181. CONDENSER only of No. 5180 - 3.50 5182. FLASK only of No. 5180 60 5183. SIPHON CUP only of No. 5180 65 5184. GOOCH CRUCIBLE, Porcelain, 25 cc, with holes for suspension; for use with No. 5180, for per- colation method i 40 5185. GLASS CONDENSER for No. 5180, of compact form, for use when desirable to avoid contact of metal with the solvent 1.00 5188. EXTRACTION APPARATUS, Knorr's, original form, consisting of a No. 5654 Flask, 100 cc, for mercury seal, No. 5189 Condenser and No. 5191 Extraction Tube 8.50 5189. CONDENSER only of No. 5188 with adapter sealed on 3.00 5654. EXTRACTION FLASK only of No. 5188, Knorr's original form, for mercury seal. Capacity, 100 cc ' 50 5191. EXTRACTION TUBE only of No. 5188, Knorr's original form, with perforated platinum disk sealed in and three glass projections to allow escape of ether vapor from the flask 5.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 231 No. 5197. No. 5204. No. 5206. No. 5212. No. 5213. No. 5214. No. 5216. 5194. EXTRACTION APPARATUS, Knorr's, modified by Walter & Goodrich. Complete with Con- denser No. 5189, extraction tube, perforated nickel lower disk and flask for mercury seal with holes for ether return, but without spring or upper perforated disk. (See Circular No. 69, Bureau of Chemistry, United States DepartJient of Agriculture) $4.35 Extra Parts for No. 5194. 5197. EXTRACTION TUBE, improved form, without projections or sealed in disk. Without wire spring or disk .45 5198. SPRING for No. 5197 to press sample against lower disk .25 5199. DISK, upper, for No. 5197, of nickel .30 5200. DISK, upper, for No. 5197, of platinum at market price 5201. DISK, lower, for No. 5197, of nickel 40 5202. DISK, lower, for No. 5197, of platinum at market price 5656. EXTRACTION FLASK, improved form, same as No. 5654, but with two holes in neck for return flow of ether 50 5204. EXTRACTION APPARATUS, Eeed's, of polished copper, for bark and wood extracts. Widely used in tanning laboratories. Complete with Soxhlet spherical condenser 33.00 5206. EXTRACTION APPARATUS for Rubber Insulating Material, as recommended by the Joint Rub- ber Insulation Committee. Consists of a glass flask of special size with condenser of the Cottle or Underwriters' form and glass siphon cup, made according to the exact specifications of the Committee. (See Journal of Industrial and Engineering Chemistry, Volume IX, No. 3, for March 1917, page 310) 3.30 5207. CONDENSER only of No. 5206 2.25 5209. FLASK only of No. 5206, of Pyrex Glass 35 5210. SIPHON CUP only of No. 5206 70 5212. EXTRACTION APPARATUS, Soxhlet's, complete with No. 5646 Flask, No. 5213 Extraction Tube and No. 5215 Allihn's Condenser, fitted with fine grained cork stoppers for connection. No A B 0 Capacity to top of siphon, cc 60 100 200 Height of siphon tube, mm 100 110 120 Approximate inside diameter, mm. 30 38 50 Suitable for extraction thimbles, mm 80x22 80x33 123x43 Length of condenser jacket, inches 6 10 Size of flask, cc 125 175 250 Each 3.25 3.60 4.50 5213. EXTRACTION TUBES only of No. 5212 1.50 2.00 2.80 5214. EXTRACTION TUBES only for No. 5212, especially designed for analysis of Cottonseed Oil, to take Extraction Thimbles No. 5248, 80x22 mm. No A B Length of siphon tube, mm 25 45 Each 1-50 5215. CONDENSERS only of No. 5212 Each 1.10 1.30 1.80 CONDENSERS, Soxhlet's, for use with No. 5212, see No. 3234. 5646. EXTRACTION FLASKS only of No. 5212. Capacity, ce 60 125 175 Approximate diameter of neck, mm 31 35 40 To take rubber stopper, No. . 7789 Each 11 .13 .17 .21 For other EXTRACTION FLASKS, see Flasks, Extraction. 5216. EXTRACTION APPARATUS, Soxhlet's, similar to No. 5212, but with all joints ground. Com- plete with three flasks ground to fit extraction tube. No ABC Capacitv to top of siphon, ce 60 100 200 Each .. 8.50 9.60 10.50 232 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 5218. No. 5222. No. 5226. No. 5232. No. 5238. No. 5244. 5218. EXTRACTION APPARATUS, Soxhlet's, -with Hopkins Inner Cooled Condenser ground to fit into Soxhlet extraction tube, with Knorr flask for mercury seal, preventing any leak of ether vapor. No A B C Capacity, to top of siphon, ce 60 100 200 Approximate inside diameter of extraction tube, mm 30 38 50 Each $7.00 8.00 9.00 6220. EXTRACTION APPARATUS, same as No. 5218, but with Sy's flask for mercury seal in place of Knorr 's. No A B Capacity, to top of siphon, cc 60 100 Each . . '. 7.25 8.50 5222. EXTRACTION APPARATUS, Teas', for the extraction of tanning materials, as used by the As- sociation of Official Agricultural Chemists. Consists of a heavy copper flask of one liter capacity, fitted with ground in copper extractor lined with tin, and a tin lined copper Soxhlet condenser. A side tube is provided for removal of percolate and for flooding the contents of the extraction tube. Height, 18 inches; diameter of flask, 7 inches 23.50 CONDENSER only of No. 5222, see No. 3234. 5223. EXTRACTION TUBE only of No. 5222. Can be used with any 750 cc Erlenmeyer flask. . . 16.50 5226. EXTRACTION APPARATUS, Underwriters' Laboratories Improved Form, with glass siphon cup. (See "Standards for Rubber Covered Wires and Cables," 1915) '. . . 3.30 5227. CONDENSER only of No. 5226 2.25 5228. EXTRACTION FLASK only of No. 5226 35 5229. SIPHON CUP only of No. 5226 70 5232. EXTRACTION APPARATUS, Wiley's, consisting of nickel-plated copper condenser, tin lined, special form, with suspended porcelain Gooch crucible, arranged to fit into straight glass tube with ground flange, rendering the use of stoppers unnecessary. Both residue and extracted matter may be easily weighed 6.50 5233. CONDENSER only of No. 5232 5.35 5235. GLASS TUBE only of No. 5232, of Pyrex glass 75 5184. GOOCH CRUCIBLE only of No. 5232, with holes for suspension 40 5238. EXTRACTION APPARATUS, Wiley's, Modified by Richardson, with glass siphon cup. Especi- ally adapted for extraction of tankage, cotton-seed meal, meat, soap, etc. (See Journal of Industrial and Engineering Chemistry, Vol. IV, No. 3, for March 1912, page 221) 6.80 5239. GLASS SIPHON CUP only of No. 5238 70 5240. GLASS TUBE only of No. 5238 .75 CONDENSER only of No. 5238, see No. 5233. 5241. PERFORATED GLASS CUP, to be used with No. 5238, in place of siphon cup for percolation purposes 60 EXTRACTION FLASKS, see Flasks, Extraction. 5244. EXTRACTION THIMBLES, Alundum, for the extraction of soaps, fats, food, rubber, etc., by both organic and inorganic solvents. Very rapid, practically indestructible and readily cleaned by ignition. Medium porosity carried in stock. Fine and coarse porosities can be supplied on short notice. Thickness of wall, approximately 1 mm. flat bottom round bottom No A B C D E Length, mm 55 70 90 100 127 Diameter, mm 35 25 19 34 45 Each .50 .45 .50 .60 1.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 233 No. 5246. No. 5254. No. 5248. No. 5260. 5246. EXTRACTION THIMBLES, Glass, with round perforated bottoms. Easily cleaned, may be used repeatedly and exact weight determined. No Length, mm . . . Diameter, mm . Each .. A 80 90 $0.45 B 80 33 .65 5248. EXTRACTION THIMBLES, Whatman's Seamless, made from the same material as the Whatman Filter Papers and rendered fat-free by a special chemical process. Can be used repeatedly. Xo A B C Length, mm 80 80 123 Diameter, mm 22 33 43 Per box of 25 3.15 3.55 7.10 5254. EXTRACTION TUBE, Roehrig's, for use in determining fat in milk and dairy products by the Roese-Gottlieb Official Method of the Association of Official Agricultural Chemists. Gradu- ated to 80 cc in 1 cc divisions with side tube and stop-cock for withdrawing solvent. Complete with ground glass stopper, on wooden base. (See Leach "Food Inspection and Analysis," page 200) 4.50 EXTRACTION APPARATUS HEATERS 5260. EXTRACTION APPARATUS HEATER, Cenco Electric, designed by W. H. Boss, consisting of a box of asbestos board 80x20x12 cm, containing a series of resistance coils over which is sup- ported a sheet iron pan. The top of the box is removable and has openings for flasks which rest upon the bottom of the iron pan. By this method the flasks rest upon a hot plate and are surrounded by hot air, thus requiring a minimum current. By means of a single switch arrange- ment, currents from 1 to 4 amperes at 110 volts, in 9 steps, may be obtained, giving a wide range of temperature for solvents at various boiling points. This may be used as an ordinary hot plate by removing the top, or as a liquid bath by using water in the iron box. The supports are adjustable in height with clamps for each extractor and condenser. Complete with covers for holes 60.00 5262. EXTRACTION APPARATUS HEATERS, Electric, similar in general construction to No. 5260, but provided with six electric lamps instead of the system of heating coils, and without the iron tray. Xo. .'. A B For volts 110 220 Each . . 47.50 48.50 234 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. ra g No. 5264. No. 5278. No. 5286. No. 5280. No. 5288. No. 5282. No. 5272. 5264. EXTRACTION APPARATUS HEATERS, Electric, similar to No. 5262, but with individual hot plates for the different flasks. As each hot plate has its own switch, any one or all may be used at one time, as desired. Length, 24 inches; width, 5% inches; height to top of hot plate, 9 inches; diameter of hot plates, 3% inches. With six hot plates. No A B For volts 110 220 Each $72.50 72.50 5270. EXTRACTION APPARATUS HEATER, consisting of rectangular water bath of tinned copper with 6 openings 2% inches in diameter, and with constant water level, on substantial support. Fitted with uprights at ends and adjustable supporting racks for extractors. Length, 23 inches; width, 4% inches; depth, 4 inches; height (not including uprights), 11 inches; height over all, 31 inches. Without glassware or burner 25.00 5272. EXTRACTION APPARATUS HEATER, consisting of a circular water bath with six 2% inch openings fitted with concentric rings, and with constant water level, on tripod support stand. A support rod with two adjustable arms is provided, equipped with spring clamps for six ex- tractors. Diameter of water bath, 12 inches; depth, 4% inches; height of top of water bath from table, 10% inches; total length of support rod, 31% inches. Complete with adjustable ring burner for illuminating gas 29.50 HOT PLATES, Electric, for extraction apparatus, see general heading Hot Plates, Electric. FAUCET CONNECTIONS, see Hose Connections. 5278. FERMENTATION TUBES, Smith's, on glass foot. No A B Length of closed tube, mm 115 140 Diameter of closed tube, mm 12 15 Each 30 .35 5280. FERMENTATION TUBES, Smith's, without glass foot. No A B Length of closed tube, mm 115 140 Diameter of closed tube, mm 12 15 Each 20 .25 5282. FERMENTATION TUBES, same as No. 5280, but without bulb. No A B Length of closed tube, mm 125 175 Diameter of closed tube, mm 12 15 Each... 15 .20 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 235 No. 5284. No. 5292. n No. 5290. No. 5312. 5284. 5286. 5288. 5290. 5292. 5296. 5298. 5300. 5302. 5306. 5312. 5314. No. 5296. No. 5298. Nos. 5314-16. No. 5300. CHART, Frost's Gasometer, for measuring gas in fermentation tubes $0.10 FERMENTATION TUBE, Standard, as adopted by the American Public Health Association. Length of closed tube, 140 mm; diameter of tube, 15 mm; diameter of bulb, 38 mm. On glass foot. (See "Standard Methods of Water Analysis," 1915, page 137) 50 FERMENTATION TUBE, Standard, same as No. 5286, but without glass foot 35 FERMENTATION TUBE SUPPORT for single tubes. Of wood with brass clip for holding tubes .^ _._._. 1.00 FERMENTATION TUBE SUPPORT, of metal, for holding 10 fermentation tubes. Can also be used for test tubes, ureometers, and any tubes not less than 5 inches long 1.60 FIGURES, Steel, see Dies No. 3820. FILES, Rat Tail, bastard cut. Length of cut portion, inches 4 5 6 8 Each 14 .16 .18 .20 FILES, Triangular, slim tapers, single cut, for use in the laboratory for cutting glass tubing. Length of cut portion, inches. Each FILES, Half Round, bastard cut. Length of cut portion, inches Each FILES, Half Round, cabinet wood rasps. Length of cut portion, inches Each FILE HANDLES, soft wood with ferrule. Diameter, inches Each Per dozen 3 .08 4 .10 5 .12 FILTERING APPARATUS i .03 .30 6 .U 8 .50 .84 .03 .30 8 .22 10 .62 10 1.04 .03 .30 FILTERING APPARATUS, consisting of Glass Bell Jar No. 1162, with heavy glass plate ground to make air tight seal, two-hole rubber stopper, 2% inch funnel, and L tube. No A B Size of bell jar, inches 5x9 6%xl 1 Size of glass plate, inches > 6x6 8x8 Each 4.50 5.00 FILTERING APPARATUS, Berkefeld Type, consisting of a porous cylinder fitted with metal head piece and outlet tube, and provided with glass mantle for holding liquids. Extensively used for sterilizing liquids of all kinds, filtering serums, toxins, etc., and in separating bacteria from cultures. They should be used in conection with Filter Flasks, No. 5664, attached to a filter pump or other means of exhausting air. Without flask or pump. No A B C D E F Height of cylinder, inches 1% 2% 5 8 8 10 Diameter of cylinder, inches % % 1 •>& '.. 1% 2 Each 1.65 2.00 3.50 4.25 4.40 5.25 236 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 5315. 5316. No. 5318. Nos. 5320-6. Nos. 5320-6. (Cross-section.) Nos. 5328-30. FILTERING CYLINDERS only of No. 5314. No ................................... A Each ................................. $1.15 GLASS MANTLES only of No. 5314. No ................. . Size, inches For cylinder, No Each B 1.25 A 50 C 2.50 D 3.00 E 3.15 BCD 4x1 5%x2V2 11x2% B C D&E .75 1.00 1.25 F 3.50 E 14x4 F 1.75 5318. FILTERING APPARATUS, for Serums, for pressure filtration. The outfit consists of a cast iron reservoir enameled inside, to which is attached the filter chamber, containing the por- ous tube or bougie. A stop-cock is provided in the connecting tube between the reservoir and filter chamber. Diameter of reservoir, 3% inches; depth of reservoir, 12 inches; height of apparatus over all, 46 inches; floor space occupied, 18x18 inches. Complete with pressure gage, pump, connecting tubing and stand as shown in illustration 125.00 5319. FILTER TUBE only of No. 5318. Length over all, S1/^ inches; width at base, 1% inches; width at top % inch 1.95 5320. FILTERING APPARATUS for Soils, Brigg's Design, as described in Bulletin No. 31 of the Bureau of Soils. Extensively used in the filtration of soil solutions. Can be used in filter- ing any solution under pressure where a clear filtrate is desired. Consists of a cylinder of brass nickel-plated on the outside and heavily plated with silver inside, fitted with a Pasteur- Chamberland filter tube of unglazed porcelain. Capacity of reservoir, approximately 800 cc 16.00 5322. FILTERING APPARATUS for Serums, Brigg's Design, same as No. 5320, but with special bou- gie for serum filtration 16.00 5324. FILTERING APPARATUS for Soils, Brigg's Design, similar to No. 5320, but of iron, porcelain lined. Capacity of reservoir, approximately 750 cc. Complete with Pasteur-Chamberland Filter Tube ..." 13.00 5326. FILTERING APPARATUS for Serums, Brigg's Design, same as No. 5324, but with special bou- gie for serum filtration 13.00 5328. FILTERING APPARATUS for Soils, Brigg's Design, similar to No. 5320, but complete with air pump and tank mounted on a substantial base. This makes a very convenient outfit for field use in soil investigations. Capacity of reservoir, about 250 cc. Complete as illustrated 30.00 5330. FILTERING APPARATUS for Serums, Brigg's Design, same as No. 5328, but with special bougie for serum filtration 30.00 •> CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 237 No. 5352. No. 5354. No. 5356. 5332. FILTERING APPARATUS for Soils, Brigg's Design, consisting of four No. 5320 Filters, mounted as shown, complete with air reservoir of 10 gallons capacity, pressure gage and spe- cial compression pump ; . . $100.00 5334. FILTERING APPARATUS for Serums, Brigg's Design, same as No. 5332, but with special bou- gies for serum filtration 100.00 5336. FILTERING APPARATUS for Soils, Brigg's Design, same as No. 5332, but with four porcelain lined Filters No. 5324 88.00 5338. FILTERING APPARATUS for Serums, Brigg's Design, same as No. 5336, but with special bou- gies for serum filtration " 88.00 5340. FILTER TUBE, for Soils, Pasteur-Chamberland, French make, for use with Nos. 5320, 5324, 5328, 5332, and 5336. Length over all, 10 inches; diameter of unglazed cylinder, 1 inch 2.00 5342. FILTER TUBE (Bougie), for Serums, Pasteur-Chamberland, French make, for use with Nos. 5322, 5326, 5330, 5334 and 5338 2.00 5346. FILTERING APPARATUS, Fitzgerald's Constant Level, consisting of a 300 cc glass reservoir, having a long glass rod fitted with a ground stopper for closing the lower opening when fill- ing the apparatus. The liquid to be filtered is introduced through the opening at the side 2.25 5348. FILTERING APPARATUS, Tray Form, consisting of glass tray with ribbed bottom and outlet at one corner. The entire surface of the filter paper is utilized, affording four times as much filtering surface from the same sheet as in a funnel. Takes filter paper 12x12 inches. Widely used for separating liquids from impurities where the weight of the separated material is not needed. Complete with supporting tripod as shown 4.50 5349. FILTER PAPER for No. 5348 Filtering Apparatus, in sheets 12x12 inches. A. For rapid filtration per 100 sheets 3.20 B. Heavy paper for finer work per 100 sheets 6.00 5352. FILTER BAGS of felt. Capacity, quarts 1 2 4 Each 2.00 2.25 2.75 5354. FILTER BALLOON, Pukal, of unglazed porcelain, for filtering solutions from outside by means of a filter pump. Height, 200 mm; diameter, 125 mm; capacity, about 400 ee 1.65 FILTER BOUGIES, see Filter Tubes Nos. 5340 and 5342. 5356. FILTER CONES, Alundum, for rapid filtration by suction, for use in any 60° funnel, to which they are attached by a wide band of rubber tubing. They have a large filtering area and can be completely washed free from all soluble salts, as the entire filtering area is within the fun- nel. They may be completely cleansed by reverse washing and ignition, and used repeatedly. Complete with wire stand for support when not in use. Medium porosity only carried in stock. Fine and coarse porosities can be supplied on short notice. No A B C D Capacity, cc 20 50 60 100 Diameter, inches 1% 2% 3 4% Height, inches 1%6 1% 2%6 3% Each 30 .35 .40 .50 5357. RUBBER GASKETS for use with No. 5356. No A B C D For filter cone, ee 20 50 60 100 Each 05 .05 .08 .10 238 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 5360. No. 5362. No. 5368. No. 5366. No. 5380. 5360. FILTER CONE, Best American Porcelain, glazed throughout except rim, with holes about 1 mm in diameter. No 3 4 Diameter, mm 50 63 Length of side, mm 43 58 Each $0.90 1.10 5362. FILTER CYLINDER, Best American Porcelain, unglazed, with flange, for filtering solutions by means of a filter flask. Length, 115 mm; diameter inside, 16 mm; diameter outside, 20 mm; diameter of flange, 50 mm 80 5366. FILTER DISKS, Perforated, Best American Porcelain, with beveled edge. Diameter, mm 25 38 50 Each 20 .30 .38 5368. FILTER DISHES, Alundum, to fit the top of a glass funnel for rapidly filtering large amounts of material. Especially adapted for organic work. Filters thoroughly, quickly and without previous preparation. Medium porosity caried in stock. Fine and coarse porosities can be supplied on short notice. No A B C Diameter, inches 5% 4 2% Depth, inches 2 2 1 Capacity, cc 400 300 50 Each 1.50 1.00 .40 5369. RUBBER GASKET, molded shape, for No. 5368A, 400 ec 50 FILTER FLASKS, see No. 5664. FILTER PAPER 5380. FILTER PAPER for qualitative work. A pure white paper of superior quality, strong and rapid. Cut in round filters, 100 in a package. Diameter, cm 7.5 10 11 12.5 15 20 25 33 40 45 50 Per package of 100 sheets. .18 .21 .23 .27 .35 .55 .88 1.26 1.48 1.85 2.20 5381. FILTER PAPER, same quality as No. 5380, in sheets 20x20 inches. Per quire 80 Per ream 12.20 5398. FILTER PAPER, J. Green for Agar Agar, similar to Chardin. The filters are folded and packed in boxes. Diameter, cm 34 50 Number in box. ' 30 25 Per box 3.25 3.25 5400. FILTER PAPER, J. Green No. 588 (S. & S. No. 588), Folded, excellent quality, free from chlorine, folded in such a way as to protect the points from tearing. In boxes of 100 filters. Diameter, cm 12.5 15 18.5 24 Per box of 100 1.00 1.20 1.50 2.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 239 WHATMAN FILTER PAPER WHATMAN FILTER PAPEES have been developed by Messrs. W. & E. Balston, Ltd., of Eng- land, the manufacturers of the well known Whatman Drawing Paper. Working in consulta- tion with Cross and Bevan, the cellulose experts, they have succeeded in perfecting a complete line of these papers, which have been acknowledged to be equal in quality, finish, and serv- ice to any previously on the market. These papers come packed in well-made carboard boxes, carefully labelled and sealed to prevent handling, each box containing 100 circles. The grades listed below offer an assortment from which one may select a paper suitable to any type of precise analytical work. In order to give an idea of the work for which each grade is best suited, we give the number of the Schleicher & Schuell, Dreverhoff or Munktell paper to which it most closely corresponds. QUANTITY PRICES. By agreement with the manufacturers we are permitted to offer the following discounts upon Whatman Filter Papers when purchased in quantities: Upon orders amounting to less than $100.00 list Net. Upon orders from $100.00 to $200.00 list 5% Upon orders above $200.00 10% (Orders may be assorted as to kinds and sizes, but must be placed at one time.) 5410. FILTER PAPER, Whatman No. 1 (S. & S. No. 595), a high grade rapid filter paper for general qualitative work and for filtering ordinary precipitates when the ash weight of the paper is of no consequence. Widely used in Sugar Laboratories and for the filtration of yellow Am- monium Phospho-Molybdate after digestion, in determining phosphorus in fertilizers. Diameter, cm 7 9 11 12.5 15 18.5 24 Ash weight per circle, grams 00046 .00076 .0011 .0016 .0021 .0032 .0054 Per 100 circles $0.20 .24 38 .37 .51 .71 1.25 FILTER PAPER, Whatman No. 1 (S. & S. No. 595), same as No. 5410, but in sheets, 46.5 x 57 cm. 5411. Per 100 sheets 4.45 5412. Per ream (500 sheets) 20.25 5414. FILTER PAPER. Whatman No. 2 (S. & S. No. 597), a qualitative paper similar to No. 1, but stouter, retaining fine precipitates. This i? the standard grade for analytical purposes. Widely used in the qualitative analysis of the alkaline earths, and in general where fine precipitates of crystalline nature are to be filtered. Especially applicable to Fertilizer, Cement, Steel, and Ore Analysis. Diameter, cm 7 9 11 12.5 15 18.5 24 Ash weight per circle, grams 0007 .0012 .0018 .0024 .0034 .0052 .0089 Per 100 circles .27 .34 .42 .52 .74 1.04 1.78 240 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 5416. FILTER PAPER, Whatman No. 3 (S. & S. No. 598), a very stout filter paper for general qualita- tive work. Slightly slower than No. 2, but very retentive. Will withstand considerable wash- ing. Especially suited for fine precipitates, such as Metastannie Acid, Calcium Oxalate, and Ammonium Phospho-Molybdate. Very satisfactory for filtering the solution of a fusion made with Eschka's mixture in determining Sulphur in coal and coke; can also be used in recovering small quantities of Silver in the form of chloride. Diameter, cm 7 9 11 12.5 15 18.5 Per 100 circles $0.40 .50 .57 .74 1.04 1.48 FILTER PAPER, Whatman No. 3, same as No. 5416, but in sheets 46.5 x 57 cm. 5417. Per 100 sheets 10.20 5418. Per ream (500 sheets) 46.40 5420. FILTER PAPER, Whatman No. 4 (S. & S. No. 604), a soft paper of more open texture than the preceding. Extremely rapid, but not recommended for use with tlje finest precipitates. Es- pecially adapted for the rapid filtration of gelatinous and large particle precipitates such as Ferric Hydroxide and Aluminum Hydroxide; also useful for Pharmaceutical purposes, such as the filtration of fruit juices, syrups, oils, etc. Widely used in Copper and other Ore Mining, Sugar and Cement Laboratories. Diameter, cm 7 9 11 12.5 15 18.5 24 Per 100 circles 30 .40 .50 .65 .90 1.30 2.22 FILTER PAPER, Whatman No. 4 (S. & S. No. 604), same as No. 5420, but in sheets 46.5 x 57 cm. 5421. Per 100 sheets 8.75 5422. Per ream (500 sheets) 39.90 5424. FILTER PAPER, Whatman No. 5 (S. & S. No. 602), a very tough, hard paper of close texture, that will retain the finest precipitates, such as Barium and Lead Sulphates even when freshly precipitated. Especially suited for use with solutions which are filtered with difficulty, and for vacuum filtration with the Buechner funnel, etc. Diameter, cm 7 9 11 12.5 15 Per 100 circles 27 .34 .41 .54 .75 5430. FILTER PAPER, Whatman No. 30 (Dreverhoff No. 207; Munktell No. O), a single-acid washed paper of low ash content, rapid and retentive. Very satisfactory for the filtration of Ammonium Phospho-Molybdate, Barium Sulphate when properly precipitated, for volumetric Lime deter- minations and for general quantitative work when the lowest ash is not important. Extensively used in Cement and Metallurgical Laboratories. Diameter, cm " 7 9 11 12.5 15 18.5 Ash weight per circle, grams .00012 .0002 .0003 .0004 .00057 .00087 Per 100 circles .68 .90 1.20 1.50 1.90 2.70 5432. FILTER PAPER, Whatman No. 31 (Munktell No. OB), a single-acid-washed paper, similar to No. 30, but more open in texture, making it more rapid. On account of its extreme rapidity it is not recommended for the finest precipitates. Suitable for the very rapid filtration of gela- tinous and large particle precipitates, for volumetric determinations of Phosphates, for Silicon in Iron Analysis, and general rapid quantitative separations where the lowest ash weight is not essential. Extensively used in Metallurgical Laboratories. Diameter, cm 7 9 11 12.5 15 18.5 Ash weight per circle, grams 00012 .0002 .0003 .0004 .00057 .00087 Per 100 circles .68 .90 1.20 1.50 1.90 2.70 5438. FILTER PAPER, Whatman No. 40 (S. & S. No. 589=. White Ribbon), a double-aeid-washed paper of very low ash, all mineral matter having been removed by treatment with hydrochloric and hydrofluoric acids. Filters rapidly and retains fine precipitates. This is the standard double- washed grade for analytical purposes. Excellently suited for Barium Sulphate when properly precipitated and filtered hot, also for Lead Sulphate, and for crystalline precipitates, such as Magnesium-Ammonium Sulphate, etc. Diameter, cm 5.5 7 9 11 12.5 15 Ash weight per circle, grams 00003 .00005 .000082 .00012 .00016 .00023 Per 100 circles 1.10 1.20 1.70 2.00 2.30 2.70 For Quantity Discounts, see Page 239. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 241 No. 5460. No. 5462. 5440. PILTER PAPER, Whatman No. 41 (S. & S. No. 589', Black Ribbon), a double-acid-washed paper similar to No. 40, but more open in texture and therefore filters more rapidly. Suitable for Iron, Aluminum, and other gelatinous precipitates which can be filtered quickly and washed rapidly and easily. Widely used in determining Silicon in Iron and Steel Analysis. Diameter, cm 7 9 11 12.5 15 Ash weight per circle, grams 00005 .000082 .00012 .00016 .00023 Per 100 circles $1.20 1.70 2.00 2.30 2.70 5442. FILTER PAPER, Whatman No. 42 (S. & S. No. 5893, Blue Ribbon), a double-acid-washed paper, similar to No. 40, but much harder and extremely close in texture. On account of its close texture it is recommended for use with the filter pump and as folded filters where possible. Especially adapted for the finest precipitates which tend to pass through the filter paper, such as Barium Sulphate when precipitated in cold solution, and in general for precise analytical work where speed is not important. Diameter, cm 5.5 7 9 11 12.5 15 Per 100 circles 1.10 1.20 1.70 2.00 2.30 2.70 5444. FILTER PAPER, Whatman No. 43 (S. & S. No. 589', Yellow Ribbon) a double-aeid-washed paper, of the same stock as No. 40, but having been subjected to an additional chemical process which renders it fat-free. Especially suited for the recovery of the ether extract in the Roese-Gottlieb Fat Test, and in general for any purposes requiring a fat-free paper. Diameter, cm 9 11 12.5 Per 100 circles 2.20 2.55 2.80 5446. FILTER PAPER, Whatman No. 44 (S. & S. No. 590), a double-acid-washed paper of thinner sub- stance and lower ash content than the preceding numbers. It will retain the finest precipi- tates, but is slightly slower in filtration than No. 40. No. 44 is recommended for use when the greatest possible degree of accuracy in quantitative work is required. Diameter, em 7 9 11 12.5 15 Ash weight per circle, grams 00003 .00005 .000077 .0001 .00014 Per 100 circles 1.50 2.20 2.55 2.80 3.60 5452. FILTER PAPER, Whatman No. 50 (S. & S. No. 575), a paper specially hardened by treatment with Nitric Acid. Very tough, will resist great pressure, and retain the very finest precipitates. Can be used repeatedly, the hard smooth surface permitting precipitates to be scraped or washed off without injury to the paper. Especially recommended for use with vacuum. Suit- able for very fine precipitates and for filtering corrosive liquids such as Acids and strong Alkalies. Should be used when it is desired to transfer a precipitate without ignition. Wide- ly used for filtering Biological products, as the hardened surface prevents contamination of the filtered product by particles of paper when scraped off. Can be used as a substitute for platinum cones, and as supports for large folded filters to prevent them bursting at the points. Diameter, cm 5.5 7 9 11 12.5 15 18.5 24 27 Per 100 circles 90 1.20 1.70 2.00 2.30 2.70 3.60 6.10 7.30 For Quantity Discounts, see Page 239. 5460. FILTER PAPER BOXES, of cardboard, square, telescoping form, to hold 100 filters. Very con- venient for keeping filters clean and free from dust. No A B C D For filters, cm 9 11 12.5 ]5 Per dozen 30 .45 .55 .60 5462. FILTER PAPER CASE, of japanned tin, convenient for holding filters of different sizes. Will take 6 sizes from 7.5 cm to 18.5 cm in diameter 242 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Plate ard Frame of No. 5468. No. 5476. No. 5478. No. 5486. No. 5480. No. 5482. 5468. 5470. 5476. 5478. 5480 548" 5484. 5485. 5486 5487. 5492. 5491. No. 5492. No. 5494. FILTER PLATES, sec Filter Disks. FILTER PRESS, Experimental Form, for making practical tests on a small scale. It is of rugged construction, with parts of iron, built to stand a pressure of 150 pounds to the square inch5. Both corrugated plates and extension frames are provided, enabling either filter paper or cloth to be used. Complete with reservoir, hand pump of iron with brass valves, pressure gage, siphon, brass discharge cocks, two filter plates, three frames, filter paper and cloth. Weight, about 125 pounds ......................................................... $75.00 FILTER PRESS, Experimental Form, same as No. 5468, but with all parts which come in contact with the material made of brass .................................................... 100.00 FILTER PUMP, Aspirator, new design, of brass. Very efficient. No ............................................................... A Length, inches .................................................... 3% Size I. P. thread, inches ........................................... % Each ............................................................ 1-50 FILTER PUMP, Richards', of brass. No .......................... .. .................................... A Length, inches .................................................... 7 Size of I. P. thread, inches ........................................ % Each ____ .- ....................................................... 1-70 FILTER PUMP COUPLING, of brass, to connect Nos. 5476 and 5478 to a threaded faucet. No ........................................................ A B C For filter pump, I. P. thread, inches ......................... % Vi Each ...................................................... 35 .35 FILTER PUMP COUPLING, of brass, to connect Nos. 5476 and 5478 with smooth No ....................................................... A B For filter pump, I. P. thread, inches ........................ % */4 Eacn ____ . .... ............................................ 65 .65 B 4% Vt 1.70 2.80 C 5% % 2.00 C 13 % 8.50 D % % .35 1.00 faucet. C D % % .65 2.50 FILTER PUMP, of brass, on base with vacuum gage, inlet and outlet tubes .............. 10.00 'FILTER PUMP, same as No. 5484, but without vacuum gage ........................... 6.00 FILTER PUMP, same as No. 5484, with vacuum gage and stop-cocks on inlet and outlet tubes ................................................................................... 12.00 FILTER PUMP, same as No. 5486, but without vacuum gage ............................ 7-50 FILTER PUMP, Geissler's, of glass .................................................. l-°° FILTER PUMP, Muencke's, of glass ................................................... 2.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 243 [PRESSURE WATER. VACUUM. {DISCHARGE. No. 5502. No. 5504. EMERGENCY INSTRUCTIONS No. 5510. No. 5520. 5502. FILTER PUMP, Water-Jet, very efficient fo use in filtration, percolation, evaporation, distilla- tion, and condensation. May be permanen ly attached or may be used with rubber tube con- nections. Requires only 10 pounds water pressure. With 20 pounds pressure, the capacity is one-third cubic foot of air per minute. A one gallon vessel may be exhausted to a vacuum of 29% inches of mercury in five minutes with 20 pounds pressure. Complete with vacuum gage, connection tee and two stop-cocks $20.00 5504. FILTER PtJMP, Steam-Jet, similar to Xo. 5502, but for use with steam instead of water. A one gallon vessel may be exhausted to a vacuum of 24 inches of mercury in seven seconds with 50 pounds pressure. Complete with vacuum gage, connecting tee, stop and check valves. . . 20.00 5510. FILTER RACKS, of galvanized iron wire with rubber ring, to hold filter paper away from sides of funnel to facilitate rapid filtration. No A B C D Diameter, inches 5 7 9 12 Each 40 .50 .75 1.00 5514. FINGER COTS, Rubber. No A B For men women Per dozen . . '. 60 .60 5520. FIRST AID CABINET. A neat hardwood case, 8x12x3% inches deep, containing: one 1-inch gauze bandage; two 2-inch gauze bandages; one 2-ineh cotton bandage to bind other dressings; one can mustard, especially prepared for emetics; two packages absorbent cotton; one package styptic gauze, medicated, to stop bleeding; one package surgical gauze, plain, for pads and com- presses; one tourniquet, to stop arterial bleeding; one can powdered antiseptic soap, for washing hands and wounds; one can Becrosco Ointment, for burns, scalds, cuts, etc.; one can Kapsikar Embrocation, for use as counter-irritant, for sprains, strains, congestion, etc.; one package court plaster; three safety pins; one envelope hooks and eyes, to hang case on wall. An excellent cabinet to have about the laboratory for treating cuts and burns. Complete as described 3.00 244 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 5532. No. 5536. No. 5540. No. 5542. No. 5546. No. 5550. FLASKS, ALL KINDS 5532. FLASKS, Flat Bottom, with ring neck. Capacity, cc 120 250 To take rubber stopper, No 1 3 Each $0.14 .17 5536. FLASKS, Flat Bottom, Resistance Grade, with vial mouth. Capacity, cc 30 To take rubber stopper, No 0 Each 11 Per 100 in original case 9.90 Capacity, cc 500 To take rubber stopper, No 5 Each 21 Per 100 in original case 18.90 5540. FLASKS, Flat Bottom, Pyrex Glass, with vial mouth. Capacity, cc 50 To take rubber stopper, No 0 Number in original case 192 Each .15 Per dozen in original case 1.62 Capacity, cc 700 To take rubber stopper, No 6 Number in original case 36 Each 36 Per dozen in original case 3.89 *Boxing charged at manufacturer's cost. 5542. FLASKS, Flat Bottom, Pyrex Glass, with heavy ring neck. 360 4 .18 500 4 .23 60 2 .12 10.80 700 6 .29 26.10 120 3 .13 11.70 1000 6 .34 30.60 750 5 .29 180 3 .14 12.60 1500 8 .42 37.80 1000 5 .36 250 4 .15 13.50 2000 9 .50 45.00 Capacity, cc To take rubber stopper, No. Number in original case. . . . Each . 500 5 72 .38 700 6 36 .47 5.08 Per dozen in original case 4.10 *Boxing charged at manufacturer's cost. 5546. FLASKS, Round Bottom, with vial mouth. Capacity, cc 60 To take rubber stopper, No 0 Each 09 Psr 100 in original case 8.00 5550. FLASKS, Round Bottom, Pyrex Glass, with vial mouth. No A Capacity, cc 100 To take rubber stopper, No 2 Number in original case 84 Each 17 Per dozen in original cass 84 *Boxing charged at manufacturer 's cost. 1000 7 36 .55' 5.94 1500 7 24 .66 7.13 2000 8 18 .78 8.42* 3000 9 12 .99 10.69* 6000 10 12 1.75 18.90* 1500 7 .42 350 5 .19 17.10 4000 9 1.10 99.00 100 150 200 300 400 500 1 1 3 4 4 6 168 108 144 96 84 72 .16 .18 .20 .23 .26 .29 1.73 1.94 2.16 2.48 2.81 3.13 1000 1500 2000 3000 6000 12000 7 7 8 9 10 10 36 24 18 12 12 6 .43 .51 .60 .76 1.60 3.00 4.64 5.51 6.48* 8.21* 17.28* 32.40* 12000 10 6 3.30 35.64* 120 250 500 750 1000 2000 2 4 5 6 6 7 .11 .14 .19 .24 .30 .48 10.00 12.00 15.00 20.00 27.00 38.00 B C D E F G H 200 300 500 700 1000 1500 2000 3 4 4 7 5 7 9 144 84 48 42 30 24 18 .22 .28 .37 .45 .56 .71 .79 2.38 3.02 4.00 4.86 6.05 7.67 8.53* CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 245 No. 5554. No. 5558. No. 5570. No. 5576. No. 5584. 5554. FLASKS, Bound Bottom, Balloon Form, Resistance Grade, with heavy vial mouth. Capacity, cc 100 250 500 1000 1500 2000 3000 4000 To take rubber stopper, No 5 6 7 8 7 9 9 10 Number in original ease 108 96 72 36 .. 18 12 Each 13 .15 .21 .34 .46 .50 .75 .1.35 Per dozen in original case $1.40 1.62 2.27 3.67 4.97 5.40 8.10 14.58 5558. Flasks. Round Bottom, Balloon Form, Pyrex Glass, with short ring neck. Capacity, cc . 200 500 1000 1500 2000 3000 5000 12000 22000 To take rubber stopper, No 368 9 10 10 11 11 12 Number in original case . 144 72 36 24 18 12 6 6 8 Each . .24 .38 .55 .66 .78 .99 1.29 3.00 6.60 Per dozen in original case 2.59 4.10 5.94 7.13 8.42 10.69 13.93 32.40 71.38 5570. FLASKS, Erlenmeyer, Resistance Grade. Capacity, cc 60 120 180 250 350 500 700 1000 1500 2000 To take rubber stopper, No. 234 5567799 Each 12 .13 .14 .15 .19 .21 .29 .34 .42 .50 Per 100 in original case.... 10.80 11.70 12.60 13.50 17.10 18.90 26.10 30.60 37.80 45.00 5576. FLASKS, Erlenmeyer, Pyrex Glass. Capacity, ee 25 50 100 150 200 250 300 500 To take rubber stopper, No 001345566 Number in original ease 360 276 180 252 144 132 132 72 Each 13 .14 .15 .16 .18 .20 .21 .27 Per dozen in original case 1.40 1.51 1.62 1.73 1.94 2.16 2.27 2.92 Capacity, cc 600 750 1000 1500 2000 3000 4000 To take rubber stopper, No 6 7 8 9 10 10 10 Number in original case 60 48 36 24 24 15 12 Each 29 .33 .42 .51 .60 .79 1.00 Per dozen in original case 3.13 3.56 4.54 5.51 6.48* 8.53* 10.80* *Boxing charged at manufacturer's cost. 5573. FLASKS, Erlenmeyer, Pyrex Glass, with extra wide mouth. Capacity, cc 250 500 750 To take rubber stopper, No 7 10 10 Number in original case 132 60 48 Each 20 .27 .33 Per dozen in original case 2.16 2.92 3.56 5584. FLASKS, Erlenmeyer, with Ground Glass Stopper, Resistance Grade. Capacity, cc 60 125 250 500 1000 Each . .45 .50 .60 .65 .90 246 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 5602. No. 5606. No. 5608. No. 5610. No. 5618. No. 5622. No. 5624. No. 5632. 5600. FLASK, Acetylizatiou, with ground in condensing tube, for assaying menthol in oil of pepper- mint. Capacity, about 150 cc; length of condensing tube, 100 cm. (See United States Phar- macopoeia for 1916, page 296) $1.50 5602. FLASKS, Assay Beaker Flasks, Resistance Grade, high form, with lip. Capacity, cc 125 250 500 1000 Number in original case 180 132 72 36 Each 13 .17 .25 .42 Per dozen in original case 1.40 1.84 2.70 4.54 5606. FLASK, Cassia, with ground glass stopper, for assaying cinnamic aldehyde. Total capacity, about 200 cc; neck graduated to 10 cc in i/10 cc divisions. (See United States Pharmacopoeia for 1916, page 289) 2.25 5608. FLASKS, Copper, heavy, polished, with ring neck. Capacity, ce. . 250 500 1000 2000 Each 2.30 2.90 3.70 5.00 5610. FLASKS, Copper Oxide, with ground glass stopper, and glass cap ground on; for keeping copper oxide pure for use in analysis. Capacity, cc 125 250 500 Each 1.50 1.80 2.40 5618. FLASKS, Distilling, Pyrex Glass, with side tube in middle of neck. Capacity, cc 50 125 250 500 1000 1500 2000 3000 Each 54 .60 .80 .96 1.30 1.85 2.10 2.60 Note: — If specified when ordering, side tube may be located where desired. 5620. FLASKS, Distilling, Opaque Fused Silica, regular form with side arm in center of neck. Liquid levels are readily visible. Capacity, cc 50 100 250 500 Each . . '. 4.05 5.95 9.40 11.25 5622. FLASKS, Distilling, Claissen's. Capacity, cc 10 60 125 250 500 Each 40 .60 .70 .80 1.20 5624. FLASKS, Distilling, Engler's, Pyrex Glass, for fractional distillation of creosote and petroleum oils. Made to standard dimensions, according to the American Society for Testing Materials and the U. S. Bureau of Mines. Capacity, cc 100 200 250 Each . . " 55 .65 .80 5632. FLASKS, Distilling, Hempel's, Pyrex Glass, for the distillation of creosote. (See Circular 112, Forest Service of United States Department of Agriculture.) Capacity, 500 cc 1.20 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. 247 No. 5644. Nos. 5646-50. No. 5654. No. 5658. No. 5664. No. 5666. Capacity, 500 ce. 250 1.10 500 1.50 5636. FLASKS, Distilling, Ladenburg's, with three bulbs in neck. 5640. FLASKS, Distilling, Lunge's Tar, with trap. Capacitv, cc. . ............................ 125 Each . . '. ...................................................... 75 Note: — Other types of distilling flasks will be made to specifications. 5644. FLASK, Elutriating, Benningsen, with neck graduated to 40 ec in 1 cc divisions. Capacity, about 4oO cc ............................................................................. 1-50 5646. FLASKS, Extraction, Resistance Grade, flat bottom, with wide mouth and vial neck. Capacity, cc ............................................ 60 125 175 250 Outside diameter of neck, mm ........................... 31 40 43 To take rubber stopper, No ............................. 8 9 Number in original case ................................ 192 120 144 96 Each ................................................... 11 .13 .17 21 Per dozen in original case ............................... 1.19 1.40 1.84 2.27 5650. FLASKS, Extraction, Pyrex Glass flat bottom, with wide mouth and vial neck. Capacity, cc ................................... 50 100 150 250 500 To take rubber stopper, No .................... 6 6 8 10 Number in original case ....................... 168 120 108 120 60 Each .......................................... 13 .15 .17 .19 .29 Per dozen in original case ...................... 1.40 1.62 1.84 2.05 3.13 5654. FLASKS, Extraction, Knorr's Original Form, for mercury seal; capacity, 100 ce ......... 50 5656. FLASKS, Extraction. Knorr's, as modified by Walter and Goodrich, with two holes in neck for return flow of ether. Capacity, 100 cc ............................................. 50 5658. FLASKS. Extraction, Sy's Form, with trough for mercury seal and with holes in neck for return of ether. Capacitv. 100 cc .......................................................... 80 For other EXTRACTION FLASKS, see Nos. 5209 and 5228. 5664. FLASKS, Filtering, Erlenmeyer form, of he ivy glass, with side neck, Capacity, cc ............................. " ............ 250 500 1000 2000 Each..'. .............................................. 50 .65 1.00 1.95 5666. FLASKS, Filtering, same as No. 5664, with glass stop-cock on side neck. Capacity, ce .................................................. 250 500 1000 Each . . '. ..................................................... 2.50 2.80 3.00 5668. FLASKS, Filtering, same as No. 5664, with side tube, and funnel ground in neck. Capacity, cc .................................................. 250 500 1000 Each..'. ..................................................... 1.65 2.00 2.75 5672. FLASK, Gray's Carbon Residue, Opaque Fused Silica, for determining the carbon residue of lubricating oils. Capacity, 50 cc. May be used repeatedly, as the residue can be burned out with oxygen. (See Report of Committee D-2 of the American Societv for Testing Materials for 1914 ... ........................................................................ 4.06 FLASKS, Gas Generating, see Gas Generators. 248 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 5694. No. 5698. No. 5704. No. B708. 5674. FLASKS, for Iodine Number Determination of Oils, Resistance Grade, Erlenmeyer form, with flaring lip and hollow stopper ground deep in neck to form reservoir. Capacity, cc 125 250 500 Each $0.90 1.00 1.20 5678. FLASKS, Joliet, for use in analysis of iron and steel. Of heavy glass, made to resist heat. Capacity, cc 500 1000 2000 Each • .29 .43 .60 5682. FLASKS, Kjeldahl, Pyrex Glass, with long neck and round bottom.- Capacity, cc ~. . 300 500 800 To take rubber stopper, No : 5 6 6 Total length, mm 298 327 365 Number in original case 60 36 36 Each .28 .37 .45 Per dozen in original case 3.02 4.00 4.86 5686. FLASK, Kjeldahl, Copper, heavy, with flat bottom. Diameter, 4 inches; height, 8% inches; capacity, 1000 cc 4 25 5690. FLASKS, Low's, for Copper Determinations Pyrex Glass, improved form, with flaring neck. Capacity, cc 180 250 Number in original case 144 108 To take rubber stopper, No 5 6 Each 25 .30 Per dozen in original case 2.70 3.24 5694. FLASKS, Melting Point or Oxygen, of Pyrex Glass, with long necks. Can be used for high tem- peratures. Capacity, cc 125 250 500 1000 Each 19 .26 .37 .56 5698. FLASK, Moisture, of Pyrex Glass, for use in official Brown-Duvel Moisture Tester for determin- ing moisture in grain. Capacity, 1000 cc. (See Circular No. 72, Bureau of Plant Industry, United States Department of Agriculture) 1.50 5702. FLASK, Moisture, Copper, single wall, for use in Brown-Duvel Moisture Tester. Capacity, 1000 cc 3.00 5704. FLASK, Moisture, Copper, double wall, for use in Brown-Duvel Moisture Tester, for determining moisture in flour and ground samples. Capacity of the inner vessel, 900 cc. (See Bulletin No. 56 of the Bureau of Plant Industry, United States Department of Agriculture) 6.00 5708. FLASKS, Phosphorus, Erlenmeyer form with narrow neck, Resistance Grade. Used extensively in iron analysis for determination of phosphorus. Capacity, 400 cc; to take rubber stopper No. 4. Number in original case, 96 Each. .25 Per dozen in original cas? 2.70 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 249 No. 5736. No. 5740. No. 5762. No. 5764. No. 5766. 5712. FLASKS, Transparent Quartz, regular shape, flat bottom, with long, narrow neck. Approx. capacity, cc.. 15 25 50 100 150 200 250 500 Each " $3.30 4.50 6.00 10.80 14.40 19.20 22.80 30.00 5714. FLASKS, Transparent Quartz, flat bottom, with short, wide neck. Approx. capacity, cc.. 15 25 50 100 150 200 250 500 Each 3.30 4.50 6.00 10.80 14.40 19.20 22.80 30.00 5716. FLASKS, Transparent Quartz, round bottom, with long, narrow neck. Approx. capacity, cc.. 15 25 50 100 150 200 250 500 Each " 3.30 4.50 6.00 10.80 14.40 19.20 22.80 30.00 5718. FLASKS, Transparent Quartz, round bottom, with short, wide neck. Approx. capacity, cc.. 15 25 50 100 150 200 250 500 Each....; " 3.30 4.50 6.00 10.80 14.40 19.20 22.80 30.00 5720. FLASKS, Transparent Quartz, Erlenmeyer form. Capacity, cc 50 100 200 500 Each..". 6.00 10.80 19.20 30.00 5724. FLASKS, Opaque Fused Silica, flat bottom, with vial mouth. These are sufficiently clear to make visible the level of liquid inside, and are specially adapted for direct heating by electric resistance wires. Very useful for boiling at high temperatures, destructive distillation, etc. Capacity cc. . 50 100 200 250 500 Each..'. 2.75 4.00 5.00 6.25 7.50 5728. FLASKS, Soil Analysis, Pyrex glass, Erlenmeyer form, with condenser tube 100 cm long ground in neck. Capacity, cc 250 500 Each . . '. 1-40 1.65 5732. FLASK, Sulphur, Pyrex glass, for use in detecting sulphured grain. Consists of an Erlenmeyer flask with ground iu stopper and delivery tube. Capacity, 500 cc. (See Circular 111 of the Bureau of Plant Industry, United States Department of Agriculture) 1.95 5736. FLASKS, Sulphur, flat bottom, with side neck bent at right angle, as used in determining sulphur in iron and steel. Capacity. 500 cc 75 5740. Flasks, Johnson's Sulphur, Resistance Grade, of heavy glass with heavy vial neck. Used widely for determining sulphur in iron and steel analysis. Capacity, 270 ce; neck of size to take No. 7 rubber stopper; number in original case, 96 Each .22 FLASKS, Vacuum, see Vacuum Tubes. Per dozen in original case 2.38 5762. FLASKS, Volumetric, accurately graduated to contain, without stopper. Capacity, ec 10 25 50 100 200 250 300 500 1000 2000 Each..'. 45 .45 .50 .50 .55 .60 .80 .85 1.00 2.00 5764. FLASKS, Volumetric, same as Xo. 5762, but with glass stopper ground in. Capacity, cc 10 25 50 100 200 250 300 500 1000 2000 Each..'. 75 .75 .80 .85 .90 .95 1.15 1.20 1.40 2.50 5766. FLASKS, Volumetric, with glass stopper and two marks on neck, graduated both to contain and deliver. Capacity, cc , 100 250 500 1000 Each 90 1.10 1.40 1.70 250 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 5768. .: - No. 5770. No. 5772. No. 5780. No. 5784. No. 5786. No. 5788. No. 5792. No. 5846. 5768. FLASK, Volumetric, Foots Flask, graduated, for determining fatty acid in cottonseed by saponi- fication. Capacity of bulb, 250 ce $2.25 5770. FLASK, Volumetric, of heavy glass, with short neck, and mark low on neck. Widely used in fertilizer laboratories. Capacity, 250 cc 65 5772. FLASK, Volumetric, graduated to deliver 58.3 ec, for determining degree of alkalinity in feed water for boilers 80 5776. FLASK, Volumetric, conical shape with enlarged mouth, as used in oil analysis. Capacity, 100 cc. 1.00 5780. FLASK, Volumetric, with wide neck, for determination of insoluble phosphoric acid. Capacity, 200 cc; diameter of neck inside, 25 mm .65 5784. FLASKS, Volumetric, Sugar, with two marks on neck, without stopper. Graduated at, cc 50 & 55 100 & 110 200.& 220 Each .60 .70 .80 5786. FLASK, Volumetric, Sugar, Bates' Form, pear shape with funnel top. Capacity, 100 cc. . .65 5788. FLASKS, Volumetric, Sugar, Kohlrausch Form, with enlarged mouth, and one mark on neck. Graduated at, cc 100 200 200.6 201.2 201.4 Each 58 .60 .70 .75 .75 5792. FLASKS, Volumetric, Gile's Form, glass stoppered, with bulb in neck and two marks. Used ex- tensively for making normal solutions, as the 10 per cent, extra volume in the bulb may be used for checking, leaving an exact volume for correction. Graduated at, ce 500 & 550 1000 & 1100 2000 & 2200 Each 2.10 2.80 4.00 5812. FLASKS, Volumetric, Precision or Normal, without stopper, graduated to meet the requirements of the United States Bureau of Standards, with unofficial factory certificate. Graduated to contain, cc 50 100 250 500 1000 2000 Each 90 1.10 1.50 1.90 2.40 3.00 5814. FLASKS, Volumetric, Precision or Normal, same as No. 5812, but standardized by the United States Bureau of Standards, with certificate. Graduated to contain, cc 50 100 250 500 1000 2000 Each 1.55 1.85 2.50 3.15 4.30 5.00 5818. FLASKS, Volumetric, Precision or Normal, same as No. 5812, but with glass stopper. Graduated to contain, cc 50 100 250 500 1000 2000 Each 1.30 1.50 1.90 2.25 3.00 3.50 5820. FLASKS, Volumetric, Precision or Normal, same as No. 5818, but standardized by the United States Bureau of Standards, with certificate. Graduated to contain, cc 50 100 250 500 1000 2000 Each 2.10 2.25 3.15 3.75 5.00 5.70 FLASK HEATER, Electric Water Bath, see No. 14296 De Khotinsky Electrically Heated Water Bath. FLASK HEATER, Electric Hot Plate, see No. 7514 Heater, Combination Electric. 5846. FLASK HEATERS, of sheet iron, with asbestos strips fastened to sides, and openings for ventila- tion. Diameter, inches 4% 5 6 7% 8*4 10V2 Each.... 80 1.10 1.30 1.60 1.80 2.20 FLASK HOLDER, Suberite, see Cork Rings, No. 3296. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 251 586& IM*. Ko. 5868. 5870. Nos. 5869-70. FLOTATION MACHINE, Brauu (patented). A miniature machine suitable for laboratory tests, built similar to the standard size, producing every effect essential to determine to what extent an ore 'will lend itself to flotation. The machine is constructed of heavy cast iron, the interior consisting of a hollow cylinder which is coated with a special hard baked enamel, a wooden drum provided with a series of longitudinal air slots, and a larger number of longitudinal riffles running the entire length of the drum. An iron strip perforated with small holes placed tangentially to the periphery of the drum admits the pulp into the frothing box. The machine is split in the center, the top being hinged, which permits ready access to every working part and facilitates cleaning. When closed the top is held in place by thumb bolts, rubber gaskets insuring a tight joint. For taking samples of tailings a small hole is provided in the bottom of the frothing box, which is closed by means of a stopper. Capacity, from one to two pounds of drv product; shipping weight, 185 pounds; dimensions 27x21x12 inches; with tight and loose pulleys, 6x2 inches; speed recommended, 400 r. p. m. Complete with directions for use.. fifcOP FEEDER FOR OILS, Braun Mechanical Disk, for nse with Xo. 5868. The problem of successful flotation depends to a great extent upon the regularity of the flow of reagents. The Braun Mechanical Disk Feeder eliminates detrimental results due to irregularity in feeding reagents. A disk of iron is mounted on a shaft and revolved within an iron tank. A thin film of oil ad- heres to the finished surface of the disk as it revolves through the oil. A portion of this film is transferred to the trough through which it flows into the flotation machine. The feed is regulated by adjusting the position of the trough by means of two micrometer screws. Grit, sludge, or any foreign matter cannot choke it. Fitted with tight and loose pulleys. Shipping weight, 120 pounds; length, 23 inches; width, 16 inches; height, 15 inches. Complete with directions for nse 54.00 FEEDER FOR ACIDS, Braun Mechanical Disk, for use with Xo. 5868, of same construction and dimensions as Xo. 5869, but with disk of lead, lead lined tank, and trough of bronze to resist action of acids. Shipping weight, 160 pounds 80.00 252 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 5930. No. 654. FLOUR TESTING APPARATUS 248. APRON, Duck, of heavy fine material, with bib and attached tie string, to protect clothing from flour and grease. Length, 50 inqhes $0.85 5906. BAKING CYLINDERS, as designed by the Columbus Laboratories, with graduated indicator and detachable cup for definite capacity. Two are desirable for comparative tests each 7.50 For Tongs for No. 5906 Baking Cylinders,- see No. 6020. BALANCE, Analytical, for Flour Testing, see Nos. 462, 466, 486 and 488. BALANCE, Porcelain Pan, for general use, see No. 648. 652. BALANCE, Baker's Scale, same as No. 648 with the exception of the scale pans which are of nickeled brass, 15 cm in diameter, and of shallow pan style. The graduated beam has a range of 10 grams in l{0 gram divisions, and brass weights from 10 grams to 100 grams are supplied, conveniently fitted into a projecting holder. The capacity is 2,000 grams. Sensibility is guar- anteed to be l/io gram. Actual tests show a much greater sensibility 10.00 656. FUNNEL SCOOP and Counterpoise, accurately adjusted, for use with No. 648 Balance. Scoop holds approximately one kilogram of flour 2.50 654. BALANCE, Flour Test, consisting of No. 648 Balance with the addition of No. 656 Funnel Scoop and Counterpoise 10.00 826. WEIGHING SCOOPS, of aluminum, with large lip and counterpoise for use in weighing flour for protein tests; size B holds approximately 12 grams of flour, size C about 50 grams. No A B C Capacity, about, cc 10 30 125 Each 2.25 2.50 4.00 BALANCE WEIGHTS for Flour Testing, see Nos. 714 and 718. BOTTLES, Sample, for Flour, see general heading Bottles. CARBONIC ACID APPARATUS, for testing Baking Powder, see general heading Carbon Dioxide Determination Apparatus. 5918. CUBIC INCH and Counterpoise. Metal box of exact inside dimensions with accurate counter- poise 6.50 EXTRACTION APPARATUS, see general heading Extraction Apparatus. FLOUR CONTAINER, of galvanized iron, see Bins and Containers. 5926. FLOUR SLICK, of finest quality spring steel, highly polished and tapered to a thin flat edge. Size, 2%x6 inches ". 75 FURNACE, Ashing, see general heading Furnaces, Muffle. 5930. JARS, Chidlow Expansion, for testing the rising qualities of dough. No A B C Capacity, cc 1000 2000 3000 Graduated in, ce 20 50 50 Each . . 2.50 2.90 3.20 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 253 No. 5938. No. 5960. No. 5933. No. 5962. No. 5972. 5932. JAE, CMdlow Gas Collection, graduated to 1800 ce in 20 cc divisions. Complete with accessory bottles, tubing and rubber stoppers $6.50 5933. JAE, Chidlow Gas Collection, the graduated jar only of No. 5932 5.00 JARS, Proofing and Dough Mixing, see Jars, Stoneware. 5938. KNIFE for mixing dough. Substantially made, with ebony handle and heavy hand forged steel blade 6 inches long .80 MAGNIFIERS for examining flour, bolting cloth, etc., see general heading Magnifiers. MILLS for grinding wheat samples, see Crushing and* Grinding Apparatus. MOISTURE TESTERS for Flour, see No. 7360, etc. NITROGEN DETERMINATION APPARATUS, see general heading Nitrogen Determination Apparatus. OVENS, Baking, see general heading Ovens. 5960. PANS, Baking, sanitary, rounded corners and bottoms. No A B Top inside, inches 8V2x4% 9%x5V2 Bottom inside, inches 7%x3% 8*£x4:1/4 Depth, inches 2% 3 Each .25 .35 Per dozen 2.50 3.50 5962. PANS, Baking, laboratory type. Depth, 5% inches; width at top, 3% inches; at bottom, 2% inches; length at top, 6% inches; at bottom, 5% inches each .70 per dozen 7.00 3844. PANS, Washing, of graniteware, round, with flat bottom, for use in washing out gluten from flour. Capacity, quarts i ., j 9 Each 30 .35 .40 3966. PLATE, glass, for slick test, 3x5 i»ches 10 1814. PORCELAIN BOWL for use in washing out gluten, so-called pint size 35 5970. PORCELAIN CUP, without handle, used in gluten washing and flour mixing 25 5972. PORCELAIN PLATE, for use in covering stone jars in proofing cabinet. Diameter, 8>4 inches .20 254 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 5978. 5970. Nos. 5978-9. PROOFING CABINETS, Despatch Electric, designed especially for dough raising in wheat and flour testing laboratories. They are made of kiln dried lumber, have glass doors, removable slat shelves, asbestos lined heater chamber and are equipped with Despatch Open Wire Elec- tric Heaters. Heaters are controlled by a two-point regulating switch system by means of which heat can be held at any temperature desired. The cases are finished in white enamel and are complete with thermometers. All sizes are 28 inches high and 14 inches deep. Despatch No 520 524 526 527 Length, inches 48 60 72 96 Number of doors 2345 For 110 volts $30.00 65.00 85.00 110.00 For 220 volti . . 50.00 65.00 85.00 110.00 No. 5982. 5982. PROOFING- CABINETS for Test Baking, Despatch Electric, of polished steel, with glass observa- tion doors and Despatch Open Wire Heaters for one heat. The walls are lined with asbestos board. Length, 29 inches; depth, 11 inches; height, 10 inches; power consumption, 200 watts. Complete with snap switch and fused entrance switch. No A B For volts HO 220 Each 27.50 27.50 PROTEIN DETERMINATION APPARATUS, see general heading Nitrogen Determination Ap- paratus. 5988. SAMPLE MAILING CASES, of heavy cardboard with tin bottom and tin screw top. Thickly coated within with paraffine, with paraffined cardboard cap for top, so that the tube is air tight. Will not lose or take on moisture in transit. 2 inches in diameter by 5 inches long. Shipping labels included per 100 8.00 per 500 37.50 per 1000 70.00 5990. SAMPLE MAILING CASES, same as No. 5988, but 2% inches in diameter per 100 9.00 SCOOPS for Flour, see general heading Scoops. per 500 42.50 SIEVES for Flour, see general heading Sieves. per 1000 80.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A, 255 No. 12096. No. 12098. No. 13514. No. 12580 No. 6026. No. 13558. No. 6020. 12096. SIEVE FRAME, without bottom, but with brass ring for holding bolting cloth, 5 inches in diam- eter , $1.00 12098. BOLTING CLOTH, Silk, for making sieves, etc. The well known Anchor Brand. Standard weight, 40 inches wide. No 2 5 7 9 11 13 15 18 20 25 Mesh per linear inch 52 64 80 96 116 130 148 168 173 200 Per linear foot 2.40 2.80 3.00 3.20 3.80 4.60 5.40 7.20 10.00 11.00 SLICKS, Flour, see No. 5926. 12580. SPATULA, Steel, special 4 inch blade, with wooden handle, designed particularly for mixing a small dough ball for gluten and absorption ,ests 90 For other SPATULAS, see general heading Spatulas. 13514. THERMOMETER, Bake Oven, of glass with 5 inch flanged metal scale with white filled figures, mounted on round disk metal base with asbestos mat attached. Range 100° to 600° F 1.50 13558. THERMOMETER, Dough Testing, of glass in 7 inch nickel-plated iron case, with 11 inch steel stem The scale is of silvered metal with black filled figures and graduations. Range, 30° to 8.00 120 "F. 0020. 6026. TONGS, Cylinder, for use with No. 5906 Baking Cylinder. Length, 24 inches, with special ,1aws 1.10 VOLUME OF LOAF APPARATUS, for determining the volume of loaves of bread by displace- ment of flax or other seed. Consists of a vessel of known capacity, sufficiently large to con- tain loaves baked in Baking Pans Nos. 5960 and 5962, having an upright tube with graduated glass face and an auxiliary funnel. In use, the bread is placed in the first container, which is then filled level full with seed. The seed is then emptied into the auxiliary funnel, and from this funnel flows evenly into the measuring vessel. From the height to which the seed rises on the graduated face of this vessel, the volume of the loaf may be read directly without calculation. Of polished brass with suitable support, graduated in cubic centimeters for loaves ranging from 1500 to 3000 cc in volume 32.50 6030. ZINC PLATES, for gluten testing, of thin sheet zinc, 2}*> inches square. In sets of twelve, numbered 1 to 12 Per set 1.00 256 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 6068. No. 6090. No. 6092. 6036. FOIL, Aluminum Leaf, for electroscopes, etc.; in books of 25 leaves, 5x5 inches. Per book §0.45 6038. FOIL, Dutch Metal (imitation gold leaf), in books of 25 leaves, 4x4 inches Per book .40 6040. FOIL, Gold Leaf (pure), for electroscopes, etc.; in books of 25 leaves, 4x4 inches. Per book 1.00 FOIL, Platinum, see Platinum Ware. FOLIN APPARATUS, see Ammonia Absorption Apparatus; Urine Analysis Apparatus. 838. FOECEPS, Brass, ivory tipped, curved points, for handling weights. Length, about 100mm 1.50 840. FORCEPS; Brass, curved points, plain. Length, about 95 mm 25 1486. FORCEPS, Blowpipe, nickel-plated with platinum tips. Length, 5% inches. Price dependent upon market price of platinum. 6058. FORCEPS, Bottle, nickel-plated, extra length, for removing articles from bottles or jars. With corrugated points and handles. Length, mm 200 250 Each 1.80 2.00 6060. FORCEPS, Cover-Glass, thin bent blades, file back, nickel-plated. Length, 105 mm 80 6062. FORCEPS, Cover-Glass, with straight blades ground thin and guide pin. Length, 115 mm .70 6064. FORCEPS, Cover-Glass, self-closing, with thin, bent blades. Length, 125 mm 1.20 6066. FORCEPS, Cover-Glass, Cornet's, self-closing, of spring brass, nickel-plated. Length, 115mm .40 6068. FORCEPS, Cover-Glass, Kalteyer's, of spring brass wire, nickel-plated, for staining on cover- glass. Length, 100 mm .45 6070. FORCEPS, Cover-Glass, Novy's, of steel nickel-plated, with corrugated handles, with one blade flat, the other curved and pointed. With guide pin. Length, 115 mm 85 6072. FORCEPS, Cover-Glass, Novy's, similar to No. 6070 but with locking device. Length, 115 mm 1.50 6074. FORCEPS, Cover-Glass, Stewart's original form, of steel wire, nickel-plated. Length, 115 mm .20 6076. FORCEPS, Cover-Glass, Stewart's, with ring; of steel wire, nickel-plated. Length, 115 mm .18 FORCEPS, Dissecting, see Dissecting Instruments. 6080. FORCEPS, Pinning, bent blades, corrugated points and handles. Length, 110 mm.... 1.35 6082. FORCEPS, Pinning, Blake Form, for heavy work. Length, 125 mm 85 6086. FORCEPS, Platinum Tipped, for general laboratory work, with corrugated handles. Length, 125 mm. Price dependent upon market price of 'platinum about 12.50 6090 FORCEPS, Slide, Kirkbride's, for staining on slide, of steel wire, nickel-plated. Length, 120 mm 12 6092. FORCEPS, Steel, heavy, for general laboratory work. Length, inches 5 6 Each $0.09 .15 6094. FORCEPS, Brass, same style as No. 6092. Length, 5 inches 18 FREEZING POINT APPARATUS, see Physical Chemistry Apparatus. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 257 No. 6100. No. 6102. No. 6106. No. 6112. No. 6114. No. 6116. 0 No. 6118. No. 6120. No. 6124. No. 6126. FUNNELS, ALL KINDS 6100. FUNNELS, Agateware. No A B C D E Capacity, pints % 1 2 4 Diameter, inches 3% 4% 5% 7% 9 Each $0.30 .35 .40 .45 .50 fi!02. FUNNEL, Agateware, for pouring chemical salts into jars and wide mouth bottles. Size, 5 inches by 4% inches 25 FUNNELS, Alundum Conical Filters, see Filtering Cones, Alundum. 6106. FUNNEL, Creosote, with stem graduated to 12 cc in i/i0 cc divisions, for estimating moisture in creosoted wood. (See Bulletin 134 of the Forest Service, United States Department of Agriculture) 2.00 (5112. FUNNELS, Glass, Bunsen, with angle of 60°, with ground rim and long slender stems ground to a point. Length of stem, about 150 mm. Diameter, mm. . 25 40 50 65 75 90 100 125 150 175 200 225 250 300 Each . . .18 .24 .25 .26 .34 .36 .38 .60 .65 .95 1.10 1.25 1.70 2.25 6114. 6116. 6118. (T120. FUNNELS, Glass, Bunsen, same as No. 6112, with constriction in stem just below funnel to in- crease rapidity of filtration. Diameter, mm 50 Each.. 30 65 .35 75 .45 90 .50 C126. FUNNELS, Glass, nest of 3; one each %, 1 and !'/& inches in diameter per nest FUNNELS, Glass, without stem, for use in sugar analysis. Diameter, mm 75 Each 70 .75 FUNNELS, Glass, with bulb in stem, for use in filtering through glass wool or cotton. Diameter, inches 4% Capacity, ounces 8 Each 85 FUNNELS, Glass Filter, so-called Carbon Filters, for use with Gooch crucibles. No A B C Diameter at top inside, mm 25 30 35 For Gooeh crucible, No 2 3 4 Each 25 .30 .35 FUNNELS, Glass, Bibbed, for rapid filtering, of heavy molded glass with smooth rim. Diameter, inches 3% 4% ' 5% 7% 8% Capacity, ounces 4 8 16 32 gals. % 1 Each 20 .25 .35 .50 .75 LIO FUNNELS, Filter Backs, see Filter Backs. 100 .60 .60 100 .80 5% 16 1.05 D 40 .46 13 2 2.00 258 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 6130. Nos. 6132-4. No. 6136. No. 6144. No. 6146. No. 6152. No. 6158. No. 6160. No. 6162. No. 6164. No. 6166. 6130. 6132. 6134. 6136. 6138. 6144. 6.50 H 300 120 14.00 FUNNEL, Hot Water, of heavy copper, single wall, with coil for heating with steam or hot water from a distance, when filtering inflammable liquids. Diameter inside, 5M> inches $5.00 FUNNEL, Hot Water, Koch's, of heavy polished copper, double walled, with detachable iron legs. Diameter inside, 5% inches 7-00 FUNNEL, Hot Water, Koch's, similar to No. 6132, but with single wall only 4.50 FUNNEL, Hot Water, Plantamour's, of tin, double walled. Diameter inside, 5V£ inches. . 4.25 FUNNEL, Hot Water, same as No. 6136, but made of heavy polished copper throughout. FUNNELS, Porcelain, Conical, perforated, see Filter Cones, Porcelain. FUNNELS, Porcelain, Buechner's, glazed, with straight sides and fixed perforated plate. No A B C D E F G Diameter outside, mm 50 60 80 100 150 200 250 Height of walls, mm 20 25 30 40 60 90 100 Each 75 1.00 1.50 1.95 3.60 5.50 8.50 6146 FUNNELS, Porcelain, Hirsch's, glazed, with conical sides and fixed perforated plate. With handle. No A B C Diameter, mm 86 120 175 Each 90 1.50 2.90 6152. FUNNELS, Hard Rubber, polished, with corrugated spout to allow escape of air. No . A B C D Diameter, inches 3*4 4% 5% 6% Capacity, ounces 4 16 24 Each.... 45 .60 .80 1.10 6158. FUNNEL, Separatory, Carnot's, for ether separations in nickel determinations in iron and steel analysis. Capacity of body, 200 cc; capacity of bulb, 100 cc, with mark at 30 cc. (See Blair's Chemical Analysis of Iron, page 178) 5.00 6160. FUNNELS, Separatory, cylindrical, open top, with glass stop-cock and long stem. No. A B C D Capacity, cc 30 60 125 250 Each.. 1.25 1.45 1.90 2.20 6162. FUNNELS, Separatory, cylindrical, same as No. 6160, but with ground in glass stopper. Capacitv, cc 60 125 250 Each..'.! 1-50 1.90 2.50 6164. FUNNELS, Separatory, cylindrical, same as No. 6162, but graduated in cc. Capacitv, cc 125 250 Each 3.00 5.00 6166. FUNNELS, Separatory, funnel shape, 60° angle ,of heavy glass, with glass stop-cock. Diameter, mm 100 150 200 Each.. 2.80 4.50 5.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 259 No. 6168. No. 6170. No. 6172. No. 6174. No. 6176. No. 6178. O 1 No. 6186. No. 6192. No. 6194. No. 6196. No. 6198. No. 6200. 6168. 6170. 6172. 6174. 6176. 6178. 6180. 6186. 6192. 6194. FUNNELS, Separatory, glob* shape, light glass, with ground glass stopper, stopcock and long stem. Capacity, ec 30 60 125 250 500 1000 2000 Each . .' $L40 1.50 2.00 235 2.85 3.90 6.50 FUNNELS, Separatory, globe shape, of heavy molded glass with glass stopper, stop-cock and short stem. Capacity, cc • 500 Each 5.40 1000 7.20 FUNNELS, Separatory, Squibb's, pear shape, with ground in glass stopper. Capacitv, ce 125 Each..". 2.30 2000 9.00 250 3.50 4000 15.00 500 6196. 6198. 6200. FUNNEL, Separatory, Straus, for the estimation of lactic acid in gastric juice; with glass stop- cock. Capacity about 30 cc, with marks at 5 cc and 25 ce 2.00 FUNNEL, Separatory, for sulphonation test of creosote, with neck graduated to 5 ce in i{0 ce divisions. Capacity, 125 cc. (See Circular 112 of Forest Service, United States Department of Agriculture) 2.50 FUNNEL, Separatory, Terrapin, for immiscible liquids, as used by the Bureau of Chemistry, United States Department of Agriculture. With ground glass stopper and glass stop-cock. Capacity, 200 cc 3.00 FUNNEL, Separatory, Walter's, for delivering single drops. With ground glass stopper and glass stop-cock. Capacity, 60 cc 2.30 FUNNEL, Shaking, for estimating phenol in creosote. (See Bulletin 107 of Bureau of Animal In- dustry, United States Department of Agriculture) 2.50 FUNNEL TUBES, conical top, straight stem. No A B Length, cm 30 40 Each 12 .19 FUNNEL TUBES, thistle top, straight stem. No A B Length, cm 30 40 Each 10 .12 FUNNEL TUBE, thistle top, with bend in stem for safety trap. Length, 300 mm 18 FUNNEL TUBES, thistle top with bend and bulbs. Length, 300 mm. >~o A B Number of bulbs 1 1 2 Each 20 .30 FUNNEL TUBE, heavy, short stemmed, with bend and two bulbs, for use with gas generators. 40 FUNNEL SUPPORTS, see Supports. 260 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. No. 6210. No. 6218. FURNACES, ALL KINDS FURNACES, COMBUSTION, ELECTRICALLY HEATED FURNACES, Combustion, Hoskins Electric, Type FD, for temperatures up to 1000° C. The heat- ing element is of Chromel wire, wound in spiral grooves upon a special refractory tube I%xl2 inches inside, and is surrounded by special packing material of high heat-insulating qualities. The element can be easily renewed by the user when burned out. Resistance wire is furnished in the proper length in spiral coils ready to be wound in the grooves upon the refractory tube. The entire renewal requires but a few minutes time and can be made if necessary while the tube is hot. A rheostat should be used to control the temperature. The furnace operates on either A. C. or D. C. with a maximum consumption of 550 watts. Widely used for determining carbon in iron and steel by tin combustion method of Vanier, Johnson and others. With con- necting cord and plug. No A B For volts HO 220 6210. Furnace only $25.00 25.00 6211. Furnace with rheostat 33.50 33.50 6212. RHEOSTATS for use with No. 6210 to control temperatures within safe working limits. No. . A B For volts 110 220 Total resistance, ohms 10 40 Each 8.50 8.50 Repair Parts for Furnace No. 6210. 6213. REFRACTORY TUBE only, without wire 3.00 6214. CHROMEL WIRE for rewinding. No A B For volts 110 220 Each 3.50 3.50 FURNACES, Combustion, Hoskins Electric, Type FB, for temperatures up to 1100°C., for con- tinuous operation. The heating element is a spiral of heavy Chromel wire, which radiates heat directly upon the combustion tube, enabling the furnace to be brought from cold to 1100°C. in only 30 minutes. As these furnaces operate on low voltages, they are best adapted for use on alternating currents in connection with a transformer. The temperature should be controlled by means of a rheostat. The element can be readily removed and replaced by the user in a few minutes in case of a burn out. Maximum power consumption, 1000 watts. Length of furnace, 12 inches; inside diameter of tube, 1% inches. Complete with connecting cord. No A B For volts 110 220 6218. Furnace only 25.00 25.00 6219. Furnace with rheostat and transformer for 60 cycles 62.00 62.00 6220. RHEOSTATS for use with No. 6218. No A B For volts 110 220 Each 11.00 11.00 6221. HEATING ELEMENTS for No. 6218. No A B For volts 110 220 Each i 5.00 5.00 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 261 G226. 6227. 6228. 6229. 6230. 6232. 6234. 6235. 6236. 8237. 6238. 6232. (1246. No. 6246. No. 6234. FURNACE, Combustion, Multiple Unit Electric, with tube I1/4xl2 inches. The heating element is made up of two units with spiral coils in longitudinal grooves, either of which may be easily re- placed by the user when burned out. Widely used for carbon determinations in iron and steel, heat treatment of small rods or tubes, and for Pyrometer calibration. Can be used inter- changeably on 110 or 220 volts A. C. or D. C., by means of a selective plug supplied with furnace. Maximum power consumption, 560 watts. Complete with six feet of flexible cord and connecting plug. Height over all, 10 inches; shipping weight, 25 pounds. Furnace only $25.00 Furnace with rheostat (voltage must be specified) 33.50 HEATING UNITS for No. 6226, wound ready for use each 3.75 REFRACTORY only of No. 6228 per unit 1.75 COILED WIRE only of No. 6228, for rewinding per unit 2.00 ALUNDUM TUBE for use with No. 6226 in calibrating Pyrometers, 12x1 inch inside diameter 2.00 FURNACE, Combustion, Multiple Unit Electric, Hinged Design, permitting inspection of combus- tion tube at any time without removing the same or disconnecting the train. Operates inter- changeably on 110 or 220 volts A. C. or D. C. Maximum power consumption, 750 watts. Ship- ping weight, 33 pounds. Height of furnace to center, 9*£ inches; length, 12 inches; inside diameter of tube, I1/! inches. Furnace only 37.50 Furnace with rheostat (voltage must be specified) 47.50 HEATING UNITS for No. 6234, wound ready for use each 5.00 REFRACTORY only of No. 6236 per unit 2.00 COILED WIRE only of No. 6236, for rewinding per unit 3.00 ALUNDUM TUBE for use with No. 6234 in calibrating Pyrometers, 12x1 inch inside diameter 2.00 FURNACES, Organic Combustion, Multiple Unit Electric, consisting of three sections, each of which can be moved along the rails for use at different points and is operated independently by means of its switch and rheostat on the base. The upper half of each section can be raised independently for inspection without disconnecting the current. The heating units are in two sections, either of which may be easily and quickly replaced by the operator in case of a burn out. The temperature of 1000°C. can be reached in 40 minutes and held constant indefinitely by means of the rheostat. Rapid cooling is obtained by raising the upper section. The life of the heating elements is about 1000 hours at temperatures not exceeding 1100°C. The trough for supporting the combustion tube is of pure nickel supported at the ends and is free from eon- tact with the furnace. Lengths of the three sections 4, 8 and 12 inches respectively; inside diameter of tube space, 1% inches; lateral adjustment of each furnace, ll1/^ inches; distance from bench to center of furnace, 9 inches; length of combustion tube required, 48 inches; total length of base, 42 inches; width of base, 9% inches; height of furnace over all closed, 12^4 inches; height over all open, 17y> inches; shipping weight, 135 pounds. No A B For volts 110 220 Each ... 125.00 125.00 262 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 6258. No. 6262. 6247. 6248. 6249. 6250. 6251. 6252. 6253. 6254. NICKEL THOUGH only of No. 6246, to support combustion tube, 39y2 inches long COMBUSTION TUBE, Pyrex, for use with No. G246. Length, 48 inches; diameter inside, HEATING UNITS for No. 6246 (two required for each section). No A B For section small medium For 110 volts, each 3.75 4 50 For 220 volts, each 3.75 5.00 REFRACTORIES only of Nos. 6249 and 6250 (two required for each section). No A B For section • small medium For 110 volts, each 1.50 1.75 For 220 volts, each 1.50 1.75 COILED WIRE for use with Nos. 6251 and 6252, for rewinding, sufficient for one unit. No A B For section i small medium For 110 volts, each 2.25 2.75 For 220 volts, each 2.25 3.25 $1.50 1 inch 2.65 C large 5.00 5.50 C large 2.00 2.00 C large 3.00 3.50 FURNACES, COMBUSTION, GAS HEATED 6258. FURNACES, Combustion, Fletcher's, for use with coal, gasoline or natural gas. Can be used with or without blast. Length of flame is adjustable at any part of furnace. Widely used for determining carbon in iron and steel. For blast purposes, use No. 1374 Foot Blower. Length, inches 12 18 24 Each 15.00 19.00 22.00 6259. FIRE-CLAY CASING BLOCKS for Furnace No. 6258, 6 inches in length each 1.00 6262. FURNACES, Combustion, Glaser's, improved form. Provided with mica plates for watching the flame during combustion. The row of burners is movable in a furrow; the burners are pro- vided with stop-cocks with separate long-handled key for turning and with nickel-plated air regulators. Complete with top plates of clay. No A B C I) Length, inches 14% 23 30 37 Number of burners 10 16 21 26 Each 37.50 50.00 60.00 75.00 6264. FURNACES, Combustion, Glaser's. same as No. 6262, but for gasoline gas. No A B C Number of burners 10 16 21 Each 45.00 60.00 70.00 6265. EXTRA TOP CLAYS for Nos. 6262 and 6264 each .60 per dozen 6.00 6266. EXTRA SIDE CLAYS for Nos. 6262 and 6264 each .25 per dozen 2.50 6267. EXTRA GUTTERS for Nos. 6262 and 6264 each .15 per dozen 1.50 6268. EXTRA STOP-COCK KEY for Nos. 6262 and 6264 1.00 FURNACE, Simple Combustion, see No. 2066. CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 263 6278. 6279. 6280. 6281. 6282. 6288. 6289. 6290. 6291. 6292. No. 6278. No. 6290. No. 6288. FURNACES, CRUCIBLE, ELECTRICALLY HEATED FURNACES, Combined Crucible and Muffle, Hoskins Electric, Type FD, with crucible chamber 2 inches in diameter by 2% inches deep. Can be heated from room temperature to 1000°C. in 30 minutes. Temperature should be controlled by means of a rheostat. Requires no special 'wiring as furnace may be connected directly to lamp socket. Maximum power consumption, 370 watts. The heating unit is easily rewound by user in case of burn out, as the refractory is spirally grooved, and the resistance wire is furnished in a spiral coil ready to wind in the grooves. The entire renewal requires but a few minutes. Complete with connecting cord and plug. Shipping weight, 22 pounds. Xo A B For volts 110 220 Furnace only $20.00 20.00 Furnace with rheostat 28.50 28.50 Not*:— Larger furnaces of the same type as Xo. 6278 can be supplied on short notice, but are not carried in stock. Send for special bulletin on Electric Furnaces. RHEOSTATS, for use with Xo. 6278 where it is desired to hold the temperature stationary at some point, or to control the variation in temperature, as h' annealing. No A B Voltage 110 220 Resistance, ohms 26.2 105 Each 8.50 8.50 REFRACTORY only for Xo. 6278, without wire 1.00 CHROMEL WIRE only for Xo. 6278, for rewinding. Xo " A B For volts 110 220 Each 1.50 1.50 Note: — The use of a Pyrometer with Xo. 6278 is desirable, as it will enable the operator to know at all times the exact temperature within the furnace chamber. ELECTRIC PYROMETERS, see Pyrometers. FURNACES, Crucible, Multiple Unit Electric, for temperatures up to 1000°C., for continuous duty. Adapted for melting metals, for determining the decalescent point of steel, and for calibrating pyrometers. Can be brought from cold to 1000°C. in 30 minutes. The heating ele- ment is in two units, either of which may be quickly replaced by the operator if burned out. Furnaces Xos. 82, 84 and 86 operate interchangeably on 110 and 220 volts. Xo. 80 is made for either voltage, but must be used with rheostat when ordered for 220 volts. Xo 80 80 82 84 86 For volts 110 220 110 & 220 110 & 220 110 & 220 Diameter inside, inches 2% 2y8 2% 3 3 Depth inside, inches 2% 2% 4 3% 5 Diameter over all, inches 7% 7% 7% 8% 8% Height over all, inches 8% 8^4 10 11 12% Rating of current for 110 volts, amperes. 3.55 . . . 4.4 5.0 6.6 Rating of current for 220 volts, amperes. ... 3.55 2.2 2.5 3.3 Maximum power consumption, watts.... 390 780 484 550 725 Kilowatt hours consumed in reaching HOOT. (760°C.) from 75°F 095 .325 .20 23 .3 Kilowatt hours consumed in holding UOO°F. (760°C.) 20 .40 .25 .325 .37 Shipping weight of furnace, Ibs 16 16 22 25 30 Shipping weight with rheostat, Ibs 20 30 26 29 34 Furnace only 20.00 25.00 30.00 37.50 Furnace with rheostat 28.50 30.00 33.50 38.50 49.50 Heating units wound ready for use, each 2.75 2.75 3.50 3.75 4.75 Refractory only 1.00 1.00 1.50 1.75 2.00 Coiled wire only for rewinding 1.50 1.50 2.00 2.00 2.75 264 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 6309. No. 6310. 6300. 6304. 6305. 6308. 6309. 6310. 6311. 6312. 6313. 6314. 6315. 6316. 6317. 6318. FURNACES, CRUCIBLE, FOR GAS AND LIQUID FUELS FURNACE, Crucible, Braun's Improved No. 8, for gasoline or gas. Can be operated with 1% inch Gary Gasoline Burner No. 2214A with a consumption of less than % gallon of gasoline per hour or with Braun Blast Burner No. 2150, with a consumption of about 150 cubic feet per hour. A removable shelf is provided for holding hot crucibles or covers. Capacity of furnace, 6 size F crucibles; shipping weight, 108 pounds $23.00 FURNACE, Crucible, Case Melting No. 3, for use with gasoline or oil. The flame blow-in is located so that the flame blows in on a tangent and does not hit the crucible until there is a complete combustion. The hot gases circle around the crucible, thereby preventing loss by cracking. Made in three sections; will take No. 7 plumbago crucible. Shipping weight, 50 pounds. Without burner 7.50 BURNER, Hydro-Carbon, for use with No. 6304, for gasoline 6.50 GASOLINE TANK OUTFIT for No. 6304, see No. 2215. FURNACE, Crucible, Fletcher's No. 40, consisting of a crucible pot with lid and blowpipe mounted on cast iron base. Operates on % inch supply of illuminating gas, using a 9A or 10A Foot Blower No. 1374 or 1376. Gas consumption, about 10 cubic feet per hour. Diameter of crucible pot, 4% inches; height of crucible pot, 5% inches; height of furnace over all, 6% inches; inside dimensions of crucible space: diameter, 2% inches; depth, 2l/2 inches; capacity of crucible, 10 ounces gold. Complete with one No. 00 clay crucible, but without blower 4.00 FURNACE, Crucible, Fletcher's No. 40A, same as No. 6308, but with injector burner. Can be used with either coal, gasoline, or natural gas, requiring % inch supply pipe and consuming 24 cubic feet per hour. Requires No. 9A or 10A Foot Blower to furnish blast. Complete with No. 00 clay crucible, but without blower 4.50 FURNACE, Crucible, Fletcher's No. 40B, same as No. 6308, but for kerosene. Requires a 9A or 10A Foot Blower. Complete with No. 00 crucible, without foot blower 6.50 Extra Parts for Furnaces Nos. 6308, 6309 and 6310. EXTRA FURNACE BODY 1.25 EXTRA FURNACE COVER 60 BURNER only of No. 6308 1.75 BURNER only of No. 6309 2.25 BURNER only of No. 6310 4.50 STAND only for Nos. 6308, 6309 and 6310, without burner or furnace body 1.00 PLUMBAGO CRUCIBLES, No. 00 each .65 CLAY CRUCIBLES, No. 00 each .08 CENTRAL SCIENTIFIC CO., CHICAGO. TT. S. A. 265 No. 6326. No. 6332. No. 6328. 6323. 6326. 6328. fir, 20. 6332. 41A 3 4% 5% 9B 8.50 3 .85 6333 6334. FURNACES, Crucible, Fletcher's Perfected Injector. Can be used on coal, gasoline or natural gas. Burner is in one easting, preventing nozzle from becoming overheated. Complete with one crucible, but without foot blower. No 41 For crucible, No Diameter of crucible space inside, inches 3% Height of crucible space, inches 3% Foot blower required to furnish blast, No 9A Each $6.00 EXTRA CRUCIBLES for No. 6322. No 1 Each 70 FURNACE, Crucible, Fletcher's Perfected Injector No. 41E, same as No. 6322, but with double in- jector burner for kerosene. Requires No. 9B Foot Blower to furnish blast. Dimensions same as No. 6322, size 41. Complete with No. 1 elay crucible and double burner, but without foot blower 11-50 FURNACE, Fletcher's Crucible and Muffle Combined, for use with coal, gasoline or natural gas, from 1$ or preferably % inch supply. Requires No. 9B Foot Blower to produce blast. Will take No. 3 crucible or No. 6 when cover is reversed, or a muffle 3%x2%x6H inches. Height of fur- nace, 11 inches; outside diameter, 9Jo inches: diameter of crucible space, 6 inches; height of irueible space, 6% inches; maximum gas consumption, 100 cubic feet per hour. Complete with injector burner, No. 3 clay crucible, and muffle 14.00 EXTRA PLUMBAGO MUFFLES for No. 6328 each 3.00 FURNACE, Crucible. Fletchers Draft No. 15, for crucibles up to 4x3*£ inches; for use without blast. The adjustable burner is of special form furnishing a number of concentric names, and will operate upon coal, gasoline or natural gas. With gas consumption of 50 cubic feet per hour, using % inch supply, it will rapidly melt a crucible of gold or silver. Height of furnace from table to top of lid, 18 inches; diameter of crucible pot, IV, inches; height of cmcible pot, 10 inches; diameter of flame space in furnace, 6*4 inches; height of flame space, 5V. inches. Com- plete with Xo. 3 clay crucible, clay cylinder and tongs, and 6 feet of pipe 19.00 Extra Clay Crucibles for No. 6332, size No. 3 each .20 Extra day Cylinders for No. 6332 each .50 266 CENTEAL SCIENTIFIC CO., CHICAGO, IT. 8. A. No. 6342. No. 6350. 6342. 6343. 6344. 6345. 6346. 6350. 6351. 6352. 6353. 6354. 6355. FURNACES, MUFFLE, ELECTRICALLY HEATED FURNACES, Muffle, Hoskins Electric, Type FD, with heating element of Chromel wire wound in spiral grooves on a special refractory muffle, surrounded by packing material with high heating insulating qualities. Heating elements can be easily rewound by user in case of burn-out, as the wire is furnished in spiral coils of the proper length ready to wind in the grooves of the muffle. The entire renewal requires but a few minutes. A rheostat should be used to keep the temperature constant at the desired point. This furnace is useful for ash determinations, igni- tion of precipitates, incinerations, fusions, combustions, enameling, hardening and annealing small pieces of steel, melting alloys and metals, etc. With connecting cord and plug, but with- out rheostat. , No 201 202 4^4x3x8 1300 60.00 71.00 9.00 8.00 203 204 2100 80.00 95.00 12.50 13.00 3400 110.00 135.00 18.50 19.00 Inside dimensions of muffle space, inches. Maximum consumption, watts 850 Furnace only $45.00 Furnace and rheostat — 53.00 Muffle only without wire 6.00 Chromel wire for rewinding 5.00 In ordering, kindly specify voltage. RHEOSTATS for No. 6342, for controlling temperature. For furnace, No 201 202 203 Each 10.00 13.00 17.00 In ordering, kindly specify voltage. FURNACES, Muffle, Hoskins Electric, Type FB, for temperatures up to 1100°C. These furnaces are designed for heavy continuous duty, and arc intended to operate on low voltages. They are therefore best adapted to operate on alternating current in connection with a transformer. Temperature control is secured by means of a rheostat in the case of No. 202 Furnace and by means of a regulating transformer in the case of No. 204. These furnaces are made for 110, 220 and 440 volts on either 60 or 25 cycles. Prices will be quoted upon request in the case of other voltages or frequencies. 204 27.00 No 202 Inside dimensions of muffle space, inches 4%x3x9 2750 90 90.00 167.50 . . 187.50 142.50 162.50 Maximum power consumed, watts. Time required to raise temperature to 1100°C., minutes. Furnace only Furnace with rheostat and transformer, 60 cycles Furnace with rheostat and transformer, 25 cycles Furnace with regulating transformer, 60 cycles Furnace with regulating transformer, 25 cycles EXTRA HEATING ELEMENTS, Hair Pin Type. For furnace, No Number of elements required Each .. 202 10 1.25 204 7%x5xl2V2 6000 90 125.00 282.50 322.50 282.50 322.50 204 10 3.00 In ordering, kindly specify voltage. Note: — Furnaces of type FB with larger muffle space than those listed can be furnished on short notice, but are not carried regularly in stock. Prices quoted upon application. CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. 267 No. 6362. No. 6372. FURNACES, Muffle, Multiple Unit Electric, for temperatures up to 955°C., for ignition of pre- cipitates, ash determinations, fusions, heat treatment of steel, melting of alloys and metals, en- ameling, etc. These furnaces are of the multiple unit type, the heating element being made in four sections forming the sides of the muffle chamber. Either of these sections may be replaced independently of the others in case of a burn-out, and all may be reversed, if desired to change from open groove to closed face, the change increasing the time of heating only 3 per cent, on account of the high conductivity of the material. The superior heat insulation of the Multiple Unit Furnaces permits a larger muffle space for the same power consumption. These furnaces can be operated interchangeably on 110 and 220 volts by means of a selective plug furnished with the equipment. The counter-weighted doors are reversible for hinging at either top or bottom of opening, and are provided with % inch air tight mica peephole. A % inch pyrometer opening is provided in rear head. A rear door of the plug type with vent hole and handle can be supplied if desired, at additional charge. Complete with six feet of flexible leads and connector plug, and with metal shelf for holding crucibles, tongs, etc. No 50 52 54 Inside dimensions of muffle space, inches. 3*4x2%x7 4%x3xlO 5%x3%xl2 Outside dimensions of furnace, inches. .. 12>4xlO»4xl4 15x12^4x16 17xl3%xl8 Shipping weight, furnace only, Ibs 65 100 135 Shipping weight with rheostat, Ibs 72 107 148 Eating of current for 110 volts, amperes. 9.1 13.1 18.8 Bating of current for 220 volts, amperes. 4.55 6.55 9.4 Maximum power consumption, watts .... 1000 1440 2070 Kilo watt hours consumed in reaching 1400°F. (760°C.) from 75°C .5 .72 1.2 Kilo watt hours consumed in holding 1400°F. (760°C.) .39 .89 1.37 6362. Furnace only $45.00 60.00 80.00 6363. Furnace with, rheostat. 55.00 72.00 96.00 6364. Extra units for top or bottom, each 3.25 5.25 7.50 6365. Extra units for side, each 2.50 3.50 5.50 6366. Refractory only for top or bottom, each. . 1.75 2.75 3.50 6367. Refractory only for side, each 1.25 1.75 2.75 6368. Coiled wire only for re-winding top or bottom, each 1.50 2,50 4.00 6369. Coiled, wire only for rewinding side, each. 1.25 1.75 2.75 6370. Rear doors, extra 5.00 5.50 6.00 Note: — Always specify voltage when order includes rheostat 6372. FURNACES, Muffle, Multiple Unit Electric, same as No. 6363, but with rheostat encased in hous- ing below furnace body, convenient for nse. This position also eliminates unsightly and dan- gerous wiring. Complete with six feet of flexible leads and connecting plug. No 60 62 64 Inside dimensions of muffle space, inches. 3Vix2%x7 4^4x3x10 5*4x3%xl2 'Outside dimensions of furnace, inches... ISxlO^xlS 14%xl2%xl6% 16M>xl3%xl9 Shipping weight, Ibs 70 105 135 Each 63.50 82.00 107.50 In ordering, kindly state voltage. For EXTRA UNITS AND PARTS for No. 6372, see Nos. 6364-6370. 268 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 6386. No. 6390. (Shown with complete outfit for use with gasoline.) FURNACES, MUFFLE, GAS HEATED 6386. FURNACES, Muffle, for all work where exact temperatures are desired not exceeding the fusing point of copper. May be operated with coal gas, natural gas, or gasoline gas without altera- tion. Complete with muffle, dome, crucible tongs and 6 feet of chimney pipe and burner. No 3 4 5 6 Inside muffle space, inches 3x4x2% 3%x5%x3 Gas pipe and tap required, inches Ya % Height from table to top of lid, inches. . 16 19J/2 Dimensions of clay parts, inches 7%x7%x8 10x9x11 Maximum gas consumption, cubic feet. . 72 96 Net weight, pounds 60 88 Each $20.00 26.00 4%x6%x4 1 1 23 27% Il%xl0%xl4 14x15^x17% 120 225 145 225 40.00 50.00 6387. 6388. 6390. 6394. EXTRA PLUMBAGO MUFFLES for No. 6386. For furnace, No 3 4 5 Each 1.75 2.25 2.75 EXTRA DOMES for No. 6386. For furnace, No 3 4 5 Each . . 1.75 2.25 2.75 6 3.25 6 3.25 FURNACE, Muffle, Braun's No. 20, for operation with gas or gasoline. Mounted on iron legs for convenience in operation. Size of muffle space, 6x12x4 inches. Shipping weight, 140 pounds. Complete with one muffle, hood, and two lengths of stove pipe, but without burner. If gasoline is used, Gary Burner No. 2214A, 1% inch, is recommended; for gas, Vulcan Non-Blast Burner No. 2146D should be used 23.00 FURNACE, Combination Muffle and Crucible, Braun's No. 40, for gas or gasoline. The construc- tion is such that the muffle is placed above the crucible compartment and the burner hole is so located as to force the flame in rotary motion around both sides of crucible compartment. The heat rising from the crucible chamber creates by suction a draft through the full length of the muffle. The cover is made in two sections to facilitate removal. The muffle draft for cupel work is obtained through a 1% inch opening in jacket and lining at rear, and the amount of air admitted is controlled by a slide in the jacket. Dimensions of muffle space, 6x10x4 inches; capacity of crucible chamber, 10 size F or 6 size G crucibles; shipping weight, 235 pounds. Complete with one muffle, hood, two lengths of stove pipe, and covers, but without burner. Cary Burner No. 2214B, 2 inch, is recommended for use with this furnace when burning gasoline or Braun Blast Burner No. 2150 for use with gas 36.50 CENTEAL SCIENTIFIC CO., CHICAGO. U. a A. 269 No. 6398 (shown with complete outfit for burning gas). No. 2150. No. 6410. 6398. FURNACE, Muffle, Gary's, No. 33, for gas or gasoline, with patent draft inducing attachment. Furnace is so arranged that special combustion chambers around the muffle distribute the fire and produce a uniform temperature in all portions of the muffle. Size of muffle, 8x12x5*4 inches; shipping weight, 250 pounds. Complete with one muffle, muffle door, hood with special draft attachment, and two lengths of stove pipe, but without burner. Gary Burner No. 2214B, 2 inch, is recommended for use with this furnace when burning gasoline, or Braun Blast Burner No. 2150 for gas $37.00 2150. BTJENEE, Braun 's Gas, for use with Furnace No. 6398, for coal or natural gas. The construction is such as to secure a mixture of gas and air which insures perfect combustion. To secure proper blast a blower must be used. (See No. 6400.) Gas should be secured from a % inch supply pipe. Shipping weight, 18 pounds. Complete with air and gas regulating valves. 15.50 6400. BLOWER and Motor Combination, for use with No. 2150. This outfit was especially designed for use with the Braun Gas Burner and is small, compact and self-contained. The motor is of a greater power than is actually required by the blower, consequently is free from over-heating. Shipping weight, 110 pounds. Without connecting pipe. No. . A B C D A. C. D. C. For volts 110 220 110 220 Each 63.00 63.00 63.00 63.00 2146. BTJENEES, Braun 's Vulcan Non-Blast, for coal or natural gas, for use with Braun Furnaces. These are non-blast burners operating without noise and upon regular gas pressure. They are so designed as to secure a correct mixture of gas and air to produce the most intense heat. Temperatures up to 2100°F. have been obtained. Each tube consumes about 50 cubic feet of gas per hour. Complete with regulating valve for each burner. No A B C D Number of burner tubes 1 2 3 4 Each 3.25 7.25 10.50 12.50 2214. BTJENEES, Gary's Hydro-Carbon, for use with Braun Furnaces, when using Tank Outfit No. 2215. The flame is clean and noiseless, and gives off no poisonous or noxious fumes. Easily generated, designed for continuous operation, and practically indestructible. Threaded to fit 14 inch standard pipe. No A B Diameter, inches 1% 2 Consumption of gasoline per hour at 35 pounds, gallons % 1 Length of burner, inches 13% 15% Shipping weight, pounds 5 7 Each 13.25 15.75 For TANK OUTFIT for use with No. 2214, see general heading Burners, Gasoline and Kerosene. 6410. FURNACE, Muffle, Wiessnegg Type, for ash determinations, incinerations, etc. Especially recom- mended for ashing in flour analysis where electric current is not available. Complete with four burners on one base, equipped with wing-tops to spread flame, and with muffle 7x4x3 inches inside 20.00 6411. EXTEA MUFFLES for No. 6410. . . .each 2.00 270 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 6416. 6416. FURNACE, Tube or Bomb, DeKhotlnsky Electrically Heated and Regulated, for use in chemical, physical and mineralogical laboratories where constant temperature is imperative during long periods, and where reaction is desired under pressure in a sealed tube. A rectangular copper container 1 mm in thickness with an end plate 1% mm in thickness is fitted with four tubes 35 mm inside diameter and 54.5 cm long, tinned inside. The container is enclosed in a box of asbestos-wood coated with white enamel, thoroughly baked on. The space (25 mm) between box and container is filled with heat insulating material (85 per cent, mag- nesia and 15 per cent, asbestos). The furnace rests on a nickel-plated stand with the usual incline of 50 mm per meter. Both ends of the furnace are provided with four electric heating units of 115 watts each, three of which may be conveniently added one by one, by means of the switch, which constitutes a part of the furnace. The fourth unit is electrically connected to our standard sensitive relay, which is automatically operated by a DeKhotinsky mercury thermo-regulator. Nickel-plated hoods, hinged at the top, are provided at the ends to prevent injury from flying glass in case of explosions. By means of the thermo-regulator the temperature of the furnace can be maintained with a pre- cision of i^o degree C. within a temperature range from that of the surrounding atmosphere to 100 degrees C., if the container is filled with water; or up to 160 degrees C. if it is filled with Criseo or oil. Outside dimensions, 55 cm long by 24 cm wide by 25 cm high. Complete with water gage, constant water level, 6 feet of connecting cord and separable plug for attachment to any lamp socket. No. . A B C D A. C. D. C. For volts 110 220 110 220 Each $112.50 115.00 110.00 112.50 Note: — In ordering A. C. Furnaces, kindly state number of cycles. 6420. FURNACE, Tube or Bomb, Carius, of iron, with openings for five tubes 20 inches long up to 1 '4 inch in diameter 15.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. a A. 271 No. 6424. (Shown In use.) No. 6436. No. 6424. (Shown in section.) 6424. FURNACES, High-Temp Electric, for temperatures from 500° to 1800°C. This is a low amperage furnace operating on either A. C. or D. C. tip to 125 volts, a feature which should commend it to users who are not equipped with transformers or generators for producing low voltage and high amperage currents. The heating element is of the granular resistance type entirely sur- rounding the cylindrical heating chamber. Outside of the heating element is a concentric cylinder of refractory material surrounded by packing of heat insulating material, making a compact furnace of a high degree of efficiency. All parts are easily replaceable at little ex- pense. With a maximum load of 40 amperes and a maximum power consumption of 2.75 kilo- watts, the furnace can be brought to a temperature of 1600° C. in an hour. A switch board is furnished with voltmeter, ammeter, circuit breaker, line switch, and rheostat for controlling the temperature. Diameter of heated chamber, 2^4 inches; depth, 3% inches; outside diam- eter of furnace, 14% inches; height over all, 19 inches. Dimensions of switch-board panel: 17 inches wide, 26 inches high, and 1 inch thick, requiring 9 inches of space for mounting. Com- plete with furnace, switchboard, 7 feet of asbestos covered flexible leads, 5 pounds of granular resistor material, and instructions for use, but without crucible. No A B For volts 110 A. C. 110 D. C. Each $205.00 195.00 6425. GRANULAR RESISTOR MATERIAL for Xo. 6424 per 5 pounds 1.50 6426. SPECIAL CRUCIBLES for No. 6424, capacity 60 cc each 1.25 Note: — Price of parts of No. 6424 for replacement furnished on request. 6436. FUSEL OIL APPARATUS, Bromwell, with stop-cock and glass stopper ground in, as used by the Association of Official Agricultural Chemists. Capacity of lower bulb, 20 cc, stem gradu- ated from 20 to 22 cc in %pth cc divisions. (See Bulletin 107, Bureau of Chemistry, United States Department of Agriculture) 5.00 272 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 6466. No. 6160. GAGES, ALL KINDS GAGES, Altitude, see Barometers. 6460. GAGE, Differential (Pitot Tube), as described by Prof. P. B. Wood-worth of Lewis Institute, Chicago, at the 1915 Meeting of The C. A. S. & M. T. Outfit includes a brass Pitot tube of correct shape and dimensions, and a glass manometer tube suitably mounted on a scale % meter long graduated in both metric and English systems. With this tube accurate measure- ments of the flow of gases and liquids may be made. It may also be used as a velocity indi- cator on motor boats and in open streams of water, or in pipes conveying air, water or steam. A set of curves is furnished with the apparatus by means of which pressure values may be converted into velocities in units of feet per second or miles per hour for either air or water. , $12.00 6464. GAGES, Draft, TJ-TUbe or siphon form, with metal fittings and removable brass bend and union. Scale graduated in }{0 inch divisions. Length, inches 4 6 8 12 18 24 Each 2.70 3.30 3.60 4.20 4.80 8.40 6466. GAGE, Draft, pocket U-fonn, armored for protection, with hose connecting piece and adjusting valve. With 6-inch scale graduated in i^0 inch divisions 7.50 GAGE, Drill, see No. 4276. 6468. GAGES, Glass Tubing, of steel, for gaging glass or metal tubing by outside diameters, with slots varying by % mm in width. No A B C D E F For tubing, mm 3 to 8 8 to 12 12 to 16 16 to 20 20 to 24 24 to 28 Each 4.50 4.50 4.50 4.50 4.50 4.50 GAGES, Heat, see Pyrometers. 6472. GAGE, Marking, of boxwood, adjustable, steel point, brass thumb screw and shoe. Six-inch scale by 16ths; 8*4 inches over all 60 GAGES, PRESSURE 6474. GAGE, Pressure, commercial type, improved single spring form, for air, steam or water pressure; iron case with nickel-plated trimming, 3%-inch dial, range 0 to 30 pounds per square inch. Provided with stopcock, and nipple for attaching hose 6.00 6475. GAGE, Pressure. Same as No. 6474, but with range 0 to 100 pounds 6.00 6476. GAGE, Combination Pressure and Altitude, especially valuable for work in hydraulics, for indi- cating the height and pounds pressure per square inch of water in pipe or reservoir. Pro- vided with stopcock, and nipple for attaching hose. To raise a column of mercury 2.04 inches or to raise a column of water 27.67 inches requires one pound pressure. Iron case with nickel trimmings, 3V2-inch dial, 0 to 30 Ibs. and 0 to 70 ft 7.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 273 Nos. 6480-2. No. 6500. No. 6490. No. 6504. No. 6510. 6478. GAGE, Pressure, Standard, so-called test gage. A gage of extreme accuracy, graduated by means of an open column of mercury and tested under the most severe conditions. Extremely sensi- tive under all pressures and guaranteed to be absolutely correct when shipped. Eange, 0 to 100 Ibs., with stopcock, and nipple for attaching hose. Entirely of brass, case nickel-plated. ?U-60 GAGE, Pressure, for gas cylinders, see Nos. 6530, 6544 and 6556. 6480. GAGE, RAIN, similar to United States Weather Bureau type, but smaller. A zinc vessel 3 inches in diameter by 13 inches long, in the top of which is placed a copper cup having an open top exactly 3 inches in diameter with sharp edge and projecting rim. The bottom of this copper cup is open and fits in the top of a brass tube 1 inch in diameter in which the amount of rain is measured. This tube is provided with an overflow opening and a wood rule graduated for reading the rainfall directly to ^looth of an inch 3.50 0482. GAGE, RAIN, United States Weather Bureau Standard, similar to No. 6480, but 8 inches in diameter and 23 inches long, with both inner and outer tubes of brass. Complete with meas- uring stick 10.00 6486. GAGE, Screw Pitch, with 24 pitches, 4 to 30 threads to the inch; V thread 1.75 6490. GAGE, Tube, of steel. For measuring the internal diameters of tubing, etc. Scale range, 1 to 15 mm. Graduated to I^Q mm 1.00 6494. GAGE, VACUUM, or MANOMETER, for use with air pumps which are provided with a vie-inch opening tapped with 16 threads to the inch. Enclosed in glass tube with oxidized scale 14 em long, graduated in millimeters. Filled with mercury, ready to attach to pump 7.00 6496. GAGE, VACUUM, or MANOMETER. To be used under any bell jar which is 8 inches or more high. Tube is mounted on a base with millimeter scale. Filled with mercury, ready for use. 1.80 6500. GAGE, VACUUM, or MANOMETER, of glass, with stop-cock and movable mirror scale graduated in millimeters for 13 cm above and below the zero line. Filled with mercury and mounted on a wood support 15.00 6504. GAGE, Vacuum. Same type and description as No. 6474. Range 0 to 30 inches 6.00 6506. GAGE, Combination Pressure and Vacuum, combining Xos. 6474 and 6504, showing both pressure and vacuum on one dial; 3%-inch dial, in iron case with nickel trimmings 7.50 6508. GAGE, Vacuum, Standard. Same type and description as Xo. 6478. Eange 0 to 30 inches. 14.60 6509. GAGE, Combination Pressure and Vacuum, Standard. Combines Nos. 6478 and 6508, showing both pressure and vacuum on one dial; 3%-inch dial. Entirely of brass, case nickel-plated. 17.75 6510. GAGE, Vacuum, McLeod's, for measuring high vacua, for use in connection with Cenco-Xelson and similar high vacuum pumps. Will read to 0.001 mm. Mounted on wooden stand, with directions for use i 45.00 GAGES, Wind, see Anemometers. 274 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 651 4A. No. 6530. No. 6540. 6514. GAGES, Wire, American standard, of best tempered steel. No A B Sizes 0 to 36 5 to 36 Each $3.00 2.50 GALVANOMETERS, see Electrical Instruments. GASES COMPRESSED IN CYLINDERS 6524. GAS, Ammonia, liquefied, in cylinders of 50 pounds per pound .50 6525. CYLINDER for No. 6524 extra (returnable for refilling only) 20.00 6528. GAS, Carbonic Acid, liquefied, in cylinders of 20 pounds, per pound 25 6529. CYLINDER for No. 6528 (returnable for credit, less a rental charge of 1 cent per day after 60 days) 30.00 Note: — If desired, name plate with name of institution will be attached without extra charge. In this case, the cylinder is returnable for refilling only. 6530. REGULATOR, Constant Pressure, for carbon dioxide tanks, for delivering carbon dioxide at any desired pressure from 5 to 300 pounds. Complete with regulator and gage reading to 300 pounds in 5-pound divisions 15.00 6532. GAS, Chlorine, liquefied, in cylinders of about 100 pounds per pound .25 6533. CYLINDER for No. 6532 (returnable for credit in good condition, less a rental charge of 50 cents per month after 90 days) 25.00 6536. GAS, Hydrogen, pure, compressed in steel cylinders. No. A B Capacity, cubic feet 25 50 Price of gas 2.50 5.00 6537. CYLINDERS for No. 6536 (returnable for credit in good condition, less a rental charge of 25 cents per week after 30 days). No A B Each 30.00 40.00 6540. GAS, Hydrogen (Illuminating Gas), for oxyhydrogen or lime light, in steel cylinders tested to 600 pounds pressure per square inch. The capacity is figured at a standard pressure of 225 pounds to the square inch. Complete with MacLachlan Patent Double Needle Valve, and with name plate engraved with name and address of institution. No A B C Capacity, cubic feet 25 35 40 Dimensions of cylinder, inches 10x34 12x36 12x42 Per cylinder filled with gas 18.75 20.00 21.25 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 275 No. 6544. No. 6556. 0042. GAS, Oxygen, for oxyhydrogen or lime light, in steel cylinders tested to 600 pounds pressure per square inch. The capacity is figured at standard pressure of 225 pounds to the square inch. Complete with MacLachlan Patent Double Needle Valve, and with name plate en- graved with name and address of institution. No A B C Capacity, cubic feet 25 35 40 Dimensions of cylinder, inches 10x34 12x36 12x42 Per cylinder filled with gas $21.85 24.35 26.25 6543. CYLINDERS for Nos. 6540 and 6542 (returnable for refilling only), refilled with oxygen or hydrogen per cubic foot .13 G.~44. PRESSURE GAGE, indispensable to users of oxyhydrogen, for measuring the amount of gas in a tank. Indicates both cubic feet and pounds pressure 6.00 6546. GAS, Nitrogen, compressed, in cylinders. No A B C Capacity, cubic feet 25 50 100 Price of gas 3.75 5.00 6.25 6547. CYLINDERS for No. 6546 (returnable for credit in good condition less a rental charge of 25 cents per week after 30 days.) Xo A B C Capacity, en. ft 25 50 100 Each 18.00 26.00 42.00 6550. GAS, Nitrous Oxide, liquefied, in cylinders of 100 gallons of gas price of gas 3.50 6551. CYLINDER for No. 6550 (returnable for credit in good condition, less rental charge of 25 cents per week after 30 days) 6.00 6554. GAS, Oxygen, pure, in steel cylinders, under pressure of 1800 pounds per square inch. No A B Capacity, gallons of gas 40 100 Size of cylinder about, inches 3%xl4 4%x24 Price of gas 2.00 5.00 6555. CYLINDERS for No. 6554 (returnable for credit in good condition less a rental charge of 25 cents per week after 30 days), complete with wheel valve and yoke to permit attachment of rubber tubing. No A B Each 7.50 13.50 6556. REGULATOR. Constant Pressure, for oxygen tanks, for maintaining a uniform pressure of gas up to 200 pounds per square inch, when delivered from high pressure cylinders. With two gages, one showing the pressure in the tank, the other the pressure delivered 35.00 6557. ADAPTER for use with No. 6556, when used on small oxygen tanks 4.00 6558. REGULATOR, Constant Pressure, same as No. 6556, but with the smaller gage reading to 30 pounds of pressure delivered, instead of 200 35.00 6560. GAS, Sulphur Dioxide, in cast iron cylinders with valve, holding about 10 pounds, complete 6.00 6561. CYLINDER for No. 6560 (returnable for refilling only), refilled with sulphur dioxide. . . 3.00 GAS ABSORPTION TUBES, see Absorption Tubes; Ammonia Absorption Apparatus. 276 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 6570. No. 6574. No. 6578. No. 6582. GAS ANALYSIS APPARATUS GAS ANALYSIS APPARATUS, as developed by the United States Bureau of Mines and used by them in the examination and precise analysis of mine air, flue and furnace gases, natural gas, and exhaust gases from gas -engines. (See Bulletins 42, 74 and 97, and Technical Papers 13, 14, 31 and 87 of the United States Bureau of Mines.) 6570. APPARATUS FOR THE EXACT ANALYSIS OF MINE AIR, Laboratory Form. Complete with glass parts mounted as shown, with iron supports. (See Bulletin 42, of the United States Bureau of Mines, figure 7, page 17) $40.00 6571. GLASS PARTS only for No. 6570 25.00 6574. APPARATUS FOR THE EXACT DETERMINATION OF METHANE, Laboratory Form. With this apparatus an analysis may be made in 10 minutes with an accuracy of 0.01 to 0.02 per cent. Complete with water-jacketed measuring burette, temperature compensating device, slow combustion pipette, manifold with two stop-cocks, manometer and leveling bulb, mounted as shown with iron supports, but without beaker or sampling tube. (See Bulletin 42, figure 11, page 31.) 38.00 6575. GLASS PARTS only for No. 6574 20.00 6578. APPARATUS FOR THE DETERMINATION OF METHANE IN MINE AIR, Portable Form. Determinations may be made with an accuracy of 0.1 per cent. Complete as shown with glass parts mounted in polished wooden carrying case with sliding doors. (See Bulletin 42, figure 13, page 34) 27.50 6579. GLASS PARTS only for No. 6578 9.00 6582. APPARATUS FOR THE DETERMINATION OF CARBON DIOXIDE AND METHANE, Port- able Form, similar to No. 6578, but with the addition of an absorption pipette for carbon dioxide. Complete as shown, in polished wooden carrying case, with sliding doors. (See Bulletin 42, figure 14, page 36) 29.00 6583. GLASS PARTS only for No. 6582 10.00 6586. APPARATUS FOR THE EXACT DETERMINATION OF CARBON DIOXIDE AND ME- THANE, Laboratory Form. With this apparatus an analysis can be made in 15 minutes with an accuracy of 0.01 per cent. Complete as shown with iron supports. (See Bulletin 42, fig- ure 15, page 38) 35.00 (For illustration of No. 6586, see page 277.) 6587. GLASS PARTS only for No. 6586 21.00 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 277 6590. MODIFIED OR SAT GAS ANALYSIS APPARATUS, Portable Form, for analyzing mine gases to an accuracy of 0.2 per cent. The absorption pipettes are filled with glass rods. Complete as shown in polished wooden carrying case. (See Bulletin 42, figure 16, page 39) .... $42.50 6591. GLASS PARTS only for Xo. 6590 25.00 6594. APPARATUS TOR 'THE ANALYSIS OP GAS MIXTURES, CONTAINING CO,, C,H4, O^ CO, H.,, CH4, CoILj, and N2. Laboratory Form. Complete with 7 pipettes including slow combus- tion pipette, water-jacketed measuring burette, compensating device, manifold tube with four stop-cocks, and leveling bulb, mounted in wooden case with iron supports. (See Bulletin 42, figure 17, page 43) 85.00 6595. GLASS PARTS only for No. 6594 55.00 6598. APPARATUS FOR THE DETERMINATION OF HYDROGEN, Laboratory Form, by means of copper oxide or palladium asbestos. Complete with water-jacketed burette, compensating de- vice, leveling bulb, palladium asbestos tube, two absorption pipettes, manifold with three stop-cocks, and iron supports, but without heater for the palladium asbestos tube. (See Bul- letin 42. figure 18, page 54) 40.00 6599. GLASS PARTS only for Xo. 6598 . . . 30.00 6602. APPARATUS FOR ANALYZING NATURAL GAS, Laboratory Form, complete as shown, with iron supports. (See Bulletin 42. figure 23. page 78) 50.00 6603. GLASS PARTS onlv for No. 6602 35.00 278 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 6612. 6606. GAS ANALYSIS APPARATUS, Burrell'S, for determining benzene or gasoline vapor in gas mixtures by the freezing method. (See Journal of Industrial and Engineering Chemistry, Vol. VII, No. 2, for February 1915, page 112; and Technical Paper 87, of the United States Bureau of Mines, page 3) $10.00 6612. GAS ANALYSIS APPARATUS, Dwights' CO2 Indicator (Patent Applied for), for determining the percentage of carbon dioxide in flue gas and other mixtures. The outfit consists of a cast metal tank with reservoir in the base holding enough solution for 300 tests. The tank is pro- vided with special inlet valve with stop-cock, and an aneroid gage reading directly in percent- age of CO2, in % per cent, divisions. The test is practically instantaneous, requiring only 1 minute to complete. Complete as described with 6 feet of rubber tubing and pressure bulb i 25.00 6613. TRAVELING CASE for No. 6612, covered with karatol grain leather, plush lined, with handle and nickel-plated trimmings, and with lock and key 3.00 6614. GAS ANALYSIS APPARATUS, Dwights' CO2 Indicator (Patent Applied for), same as No. 6612, but with mercury gage mounted on the door of the carrying case, for obtaining the per- centage of COo. The gage is specially designed to prevent spilling of mercury and is pro- vided with an adjustable scale enabling the mercury level to be brought to zero when beginning a test. Complete as described with 6 feet of rubber tubing and pressure bulb, leather covered carrying case, plush lined, with handle, nickel-plated trimmings, and with lock and key. 28.00 CENTBAL SCIENTIFIC CO., CHICAGO, TT. 8. A. 279 No. 6628. No. 6632. No. 6636. No. 6650. C628. GAS ANALYSIS APPARATUS, Orsat-Muencke, for the analysis of CO2, CO, and O2, especially adapted for furnace and flue gases. Consists of three absorption pipettes, manifold tube with four stop-cocks, measuring burette with water jacket, and aspirator bottle. Complete in portable polished wooden case $35.00 6629. EXTRA MANIFOLD TUBE for No. 6628 with four stop-cocks 9.50 (5632. GAS ANALYSIS APPARATUS, Great-Fischer, designed for portability. Similar to No. 6628, but about half the size, with drying tube inside case, attached to manifold. Complete with three pipettes, in portable polished wooden case 35.00 6633. EXTRA MANIFOLD TUBE for No. 6632, with four stop-cocks 9.50 6636. GAS ANALYSIS APPARATUS, Orsat-Lnnge, similar to No. 6628, but with four pipettes and bent palladium tube with lamp, for separate estimation of hydrogen. Complete with drying tube, in portable polished wooden case 42.50 6637. EXTRA MANIFOLD TUBE for No. 6636, with five stop-cocks 12.00 6638. EXTRA BENT PALLADIUM TUBE for No. 6636 4.00 Extra Parts for Orsat Gas Apparatus Nos. 6628, 6632 and 6636. 6640. ABSORPTION PIPETTE, plain 2.00 6641. ABSORPTION PIPETTE, filled with glass tubes 2.50 6642. ABSORPTION PIPETTE, filled with glass tubes and copper spirals 3.50 6643. MEASURING BURETTE only without water jacket 5.50 6644. WATER JACKET only for measuring burette 1.25 1614B. ASPIRATOR BOTTLE, 8 ounces 70 6645. SOFT RUBBER BAG for attaching to pipettes (for illustration, see page 428) 60 6832. RUBBER ASPIRATOR BULB with two valves and rubber connections (see page 428) ... .60 6650. GAS ANALYSIS APPARATUS, Petterson-Palmqulst, for determining small quantities of CO2 in air. This is the standard laboratory apparatus recommended by the American Public Health Association for investigations of ventilation in schools, factories, public buildings, etc. Complete in polished wooden case. (See American Public Health Journal, Vol. "VTI, No. 1, for January 1917) 55.00 280 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 0652. . .30 7316. GERMINATING PLATE, of porous clay, 9 inches in diameter. Obviates the use of blotting pa- per in germination experiments .24 3592. GERMINATING PLATE, of porous clay, 4^6 inches in diameter by 7{6 inch deep, with straight sides 20 300 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 7320. 7322. 7324. 7328. 7330. 7336. 7338. 552. 7344. 7346. No. 7330. No. 7324. No. 7346. GERMINATING PLATE, of graniteware, 11 inches in diameter by 1% inches deep. For use with moist blotting paper in germination experiments $0.35 GERMINATING TRAY, of water-proofed wood, 25x25x2% inches deep, for testing fertility of corn and other grain. A frame which fits into the tray is divided into 144 squares- which may be numbered if desired. (For illustration, see preceding page) 5.50 GERMINATING TRAY, of wood, 18x10x2 inches deep 2.00 GERMINATION OR SPROUTING APPARATUS, Schoenjahn's Patent, for quickly determin- ing the percentage sprouting value of barley, showing its malting quality. Equally efficient in showing sprouting value of all grains. Capacity, 100 grains. Complete with directions for use 7-50 GERMINATION OR SPROUTING CUP, as described in Bulletin No. 35 of the Rhode Island Experiment Station, and on page 14 of Bailey's "Nursery Book." Of porous clay 3 inches in diameter by 1% inches high, with ventilated cover and glass dish 50 GERMINATION TESTER, Sho-Gro, oil heated, constructed throughout of non-rustable metal and glass. It has a capacity of 5 trays, each measuring 10x15 inches, so that a large number of samples may be accommodated at one time. The outside measurements over all are 32 inches high, 13 inches wide, and 17 inches deep. Since all sides are of glass, the progress of the test is always in view. Complete with 24 blotters, a supply of dividing- strips and oil lamp for heating 15.00 GERMINATION TESTER, Sho-Gro, same as No. 7336, but electrically heated, with switch for three heats 23.00 In ordering, kindly state voltage of circuit. GRAIN' CONTAINER of galvanized iron, see Bins and Containers. GRAIN OR SEED SCALE (Dirt Scale), for ascertaining the percentage of dirt in grain or seed. The beam has two rows of marks, the upper indicating the weight, one pound by quar- ter ounces; the lower the percentage of dirt. In use a sample pound is weighed, sifted, and replaced in the scoop. The poise is th*n run back until the beam balances. The lower row of marks shows the percentage of loss by dirt removed, i. e., the percentage of dirt contained in the seed. Complete with brass scoop 12.00 GRAIN TESTER, Grobecker's, of nickeled brass, for determining rapidly the farinaceous con- dition of barley and malt. Fifty kernels may be cut through at a time 9.00 GRAIN TESTERS, of best construction, highly polished and lacquered. When the cup is empty the beam balances with the poise set at zero. Beam has three rows of graduations which indicate the number of pounds per bushel of sample, the exact weight of sample, and the percentage of loss in cleaning. Capacity 1 pt. 1 qt. 2 qt. Each 18.00 20.00 22.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 301 7347. 7360. 7362. 7364. 5698. 5708. 5704. 7368. 3662. 3664. 7371. 7372. No. 7347. No. 7362 (including No. 7374). GRAIN TESTEE TILLERS, for use with No. 7346 Grain Testers. This device is of special value when accurate testing is desired, since it allows the grain to flow in a uniform stream and insures a uniform density in the cup. Complete with polished steel rod for striking off. Capacity, quarts . . 1 2 Each $8.00 10.00 Note: — The above fillers may be used with any grain testers of capacity equal to or smaller than that of the filler. MAGNIFIERS, for Grain, see general heading Magnifiers. MOISTURE TESTERS, Official Brown-Duvel, developed primarily to meet the needs of grain dealers for a rapid and exact method of determining the moisture in corn. Methods have now been worked out for making moisture tests of the more important cereal grains and some of the more important seeds, as well as for flour and ground grain. The method is entirely prac- ticable for making moisture determinations of practically all substances which admit of a free circulation of oil during the heating. The apparatus consists of a heating chamber divided into compartments for testing a number of samples at the same time; a cold water tank through which condenser tubes pass; burners; thermometers; special side neck flasks; gradu- ated cylinders; and No. 7374 Automatic Oil Measuring and Grain Separating Device. Testers B, C and D are 12% inches -wide and 31 inches high. No. A is especially adapted for field work and is put up in a carrying case 11 by 7 by 15 inches; weight complete, 19 pounds. These testers are the standard form as specified in Paragraph 11 of the Federal Corn Grades, effective July 1, 1914. (See Bulletins Nos. 56 and 99, and Circular No. 72, Bureau of Plant Industry, United States Department of Agriculture.) No. . A B C D Number of compartments 1 2 4 6 Length, inches 6% 13 26 39 With gas burners 27.00 40.00 55.00 70.00 With alcohol burners 27.00 40.00 55.00 70.00 With electric heaters 35.00 56.00 87.00 118.00 Note: — In ordering No. 7364, kindly state voltage of circuit. Parts and Accessories for Moisture Testers. FLASK, Pyrex Glass, 1000 cc 1-50 FLASK, Copper, single wall, 1000 cc 3.00 FLASK. Copper, double wall, inner vessel 900 cc 6.00 CONDENSER TUBE, of glass 30 GRADUATED CYLINDERS, 25 cc, graduated in % cc 65 GRADUATED CYLINDER, new design; for use when 50 gram samples are being tested. With this graduate the percentage of water up to 16 per cent., is given by direct reading without the necessity of multiplying by two, as with the original graduate 85 OIL for moisture testers, 'according to the specifications of the Bureau of Plant Industry, in metal cans. No A Capacitv, gallons 1 Each .'.. 90 3.25 RUBBER STOPPERS, especially designed to stand the high temperature existing in moisture test flasks: are absolutely necessary when copper flasks are used. No 6 Per dozen.. 1-65 302 CENTRAL SCIENTIFIC CO., CHICAGO, XT. S. A. 7373. 7374. 7380. 7382. 7384. 7386. No. 7402. No. 7398. 7398. 7402. 7410. 7412. 7414. 5732. THERMOMETER, graduated from 0° to 200° Centigrade, specially designed for moisture test- ers $2.00 AUTOMATIC OIL MEASURING AND GRAIN SEPARATING DEVICE, consisting of a gal- vanized iron tank, re-enforced strongly with brass, and so mounted on brackets that it can readily be attached to any of the moisture testers; fitted with a measuring device which automatically measures out 150 cc of oil into test flask by merely pushing the neck of the flask upward against an automatic catch. The cover of the tank is fitted with a funnel- shaped sieve, which catches the mixture of grain and oil as it is poured from the flask after the test, and strains- the oil into the container below. In this way the oil is kept free from dust and dirt, and the same oil may be used repeatedly 5.00 FANS, Sample, of aluminum; for use in sampling and inspecting grains, with one end formed into a spout for pouring out contents. Strong, light, and well made; will not rust or tar- nish; upward pitch of spout prevents grain from rolling out. Recommended in Bulletin No. 99 of the Bureau of Plant Industry. Size 9x6x1% inches each 1.40 PROTEIN DETERMINATION APPARATUS FOR GRAIN, see general heading, Nitrogen De- termination Apparatus. SAMPLER, Bag, for sampling small seeds in sacks. Diameter, %2 inch; length, 4% inches 1.10 SAMPLER, Bag, similar to No. 7382, but for grains. Diameter, % inch; length, 6 inches. . . 1.50 SAMPLERS, Grain, consisting of two polished brass tubes, one fitted inside of the other, and having openings matching each other. By turning the handle, the inner tube is revolved, thus opening and closing the holes. No A Diameter, inches 1*4 Length, inches 44 Each 9.00 SIEVE, Corn Test, of aluminum, according to specifications of the United States Department of Agriculture, consisting of one sieve with i%4 inch round holes and one bottom pan, nested, 13 inches in diameter by 3 inches deep per set 4.50 SIEVES, Wheat Dockage, according to Government specifications, consisting of a set of four sieves, 13 inches in diameter, and bottom pan, constructed of aluminum, telescoping. Con- sists of a buckwheat sieve with %4 inch triangular perforations; a fine seed sieve with i/j2 inch round perforations; a scalper sieve with i%4 inch round perforations; and a chess sieve with perforations 4%/64 by % inch. (See Regulatory Announcement No. 22 of Federal Wheat Grades effective July 1 and August 1, 1917) 8.00 SPROUTING MEDIA PROPAGATING SAND, best quality, clean and fertile per peck SAWDUST, for germinating trays, specially selected per peck SPHAGNUM MOSS, best quality, for germinating boxes per pound SULPHUR DETERMINATION APPARATUS, for determining whether grain has bleached, as recommended in Circular No. Ill of the United States Bureau of Plant Industry. Consists of an Erlenmeyer flask with ground in stopper and connecting tube. Capacity, 500 cc 1.95 For SEED AND GRAIN SAMPLES AND TYPES, send for Catalog of Agricultural Apparatus. 44 12.00 C 1% 52 12.25 .50 .25 .25 been CENTRAL SCIENTIFIC CO., CHICAGO, U. a A. 303 No. 7424. No. 7460. No. 7468. 741:2. 7424. 14S8. -- •'. 746S. 74^4. For GOUGES see Chisels. GRINDSTONES. Selected Berea grindstones, rubbed smooth, mounted in a east iron trough, with pressed steel base, steel shaft and steel ball bearings. Shipped knocked down. Diameter, inches 6 10 Each $2.90 3.60 GRINDER, with clamp for fastening to table 2 inches thick or less. High quality abrasive wheel 4 inches in diameter, 1 inch face; gears enclosed for protection '. 7.00 HACK-SAWS, see Saws. HAEMATOLOGY APPARATUS, see Blood Testing Apparatus. HAMMERS, of cast steel, wedge shaped, for breaking ores. Xo A B Weight, ounces 7 16 Each 85 1.00 HAMMER. Blowpipe, Planner's, with wooden handle 45 HAMMERS, Claw, cast steeL No A B Weight, ounces 7 • 13 Each -. 1.15 1-25 HAMMER, Prospecting Pick, of cast steel, square head with flat face. Pick point of hardened steel. Weight I1* pounds 24JO HAND TALLY, see Counter No. 3318. HARDNESS TESTERS For a full discussion of methods of measuring hardness of metals, see Technologic Paper No. 11 of the United States Bureau of Standards. HARDNESS TESTER. Brinell Ball Type, for maximum pressure of 3,000 kilograms, for deter- mining comparative hardness by the Brinell ball indentation methodl This instrument is con- sidered the standard for hardness tests and is widely used by steel manufacturers and users throughout the world. The machine is of the hydraulic type, using glycerine as the pressure medium. The press is so constructed that no air can leak in behind the plunger. A special feature of this method is the automatic depth gage by which the depth of tte indentation may be read directly without calculation and the corresponding Brinell number obtained from a table supplied with each machine. Shipping weight. 700 pounds. Complete as described, filled with glycerine, but without Automatic Depth Gage 315.00 304 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 7485. 7486. 7487. 7492. 7494. 7495. No. 7485. No. 7486. No. 7487. No. 7492. AUTOMATIC DEPTH GAGE for reading directly in hundredths of a mm the depth of indenta- tion of the Brinell sphere. The depth of the indentation has been shown by the United States Bureau of Standards to be the correct method of comparing the hardness of metals. The total scale of 150 represents an indentation of I1/-; mm. Complete in leather covered case. .$65.00 MICROMETER MICROSCOPE for use with No. 7484 Hardness Tester for those who wish to measure the diameter of indentation. Reads directly in mm to an accuracy of 0.001 mm. Height of support, 12 inches; length of side arm, 8 inches. Complete with achromatic ob- jective of 42 mm focus, ocular with stationary cross hairs, rack-and-pinion movement for focusing and graduated micrometer screw for lateral motion mounted on heavy support with universal adjustment 65.00 BRINELL MAGNIFIER, hand type, for reading approximately the diameter of the indentation. Consists of a magnifying lens and a small steel rule graduated in fifths of a mm. Readings can be made to ^0 mm 10.00 HARDNESS TESTER, Brinell Meter, a portable instrument for determining the hardness of metals by comparing the diameters of the depressions produced in the test piece and a stand- ard piece of known hardness, by a sphere under the influence of the same force. The ad- vantages of such an instrument over other types are its portability, unlimited range of appli- cation, rugged construction and convenience in operation. Complete with one Brinell Meter, 12 standard 10mm balls, 6 standard bars of carefully determined Brinell hardness, 2 special scales for measuring the diameter of indentation, key for opening instrument and a set of direct-reading tables, with instructions for use, in leather covered carrying case, 9x6 inches; total carrying weight, 6^ pounds. (Unless specified, 3 bars of hardness 170 Brinell and 3 of 250 Brinell will be sent.) Descriptive booklet will be sent upon request 55.00 7493. STANDARD BARS for No. 7492 each .75 (In ordering, specify degree of hardness desired, and give serial number of instrument with which they are to be used.) STANDARD STEEL BALLS for No. 7492, exactly 10 mm in diameter per 9ozen 1.00 MEASURING SCALES for No. 7492, graduated to %0 mm, for reading to 140 mm- No •. A B Beading, mm 1.5 to 3.5 3 to 5 Each 15 .15 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 305 No. 7498. No. 7498. Nos. 7508-9. 7498. HARDNESS TESTEE. Scleroscope, Shore's, for determining the comparative hardness of metals. The method consists in dropping a small hammer from a fixed height upon the piece being tested, and measuring the height of the rebound upon the scale, which reads directly in de- grees of hardness. Complete with Scleroscope, plastermount vessel, stand with swinging arm, magnifier, hammer for soft metals, one each brass and hard steel, calibrated reference bars, and 50 blank curve charts in polished wood carrying case. Descriptive booklet sent upon request $170.00 HARDNESS SCALE, see Blowpipe Apparatus. 7500. HATCHET, high grade steel, black finish, polished face and bevel, selected white hickory handle, 3% inch bit 1.25 HEAT GAGES, see Pyrometers. HEATEES, Electric, for Extraction Apparatus, see Extraction Apparatus Heaters, Nos. 5260 to HEATERS. Electric, for ether extractions, Kjeldahl digestions, etc. Consists of six electric hot plates. 3^ inches in diameter, mounted on a sheet iron box. Each heater has its own switch, enabling any number to be used at a time. Lenth, 24 inches; width, 5*4 inches; height, 9 inches. Complete with rack for Kjeldahl flasks, and with connecting cord and plug. 7508. 7509. No Number of hot plates. Length, inches For 110 volts For 220 volts. . A 6 24 57.75 57.75 B 10 40 90.75 90.75 7512. HEATER, Cenco Electric, for Volatile Fluids, designed by W. H. Ross, consisting of a box 80x20x12 cm of asbestos board containing a system of resistance coils, above which is sup- ported a sheet iron pan. The top of the outer box is removable and has openings for flasks which rest on the bottom of the iron pan below. A switch arrangement permits the use of currents of from 1 to 4 amperes at 110 volts, the change from minimum to maximum being made in nine steps if desired. With top removed, the heater becomes an ordinary hot plate. By placing a liquid in the iron box the heater becomes a liquid bath. Complete with covers for holes . , 37.50 306 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 7520. !» No. 7514. No. 7518. 7514. HEATERS, Electric Combination Flask, Sand Bath, and Hot Plate. Constructed with replace- able unit, and with housing of heavy sheet steel containing rheostat for temperature control. Upper part of casing is flanged to form slide for several appliances. Maximum temperature obtainable, 540°C. (1000°F.), which can be controlled sufficiently low for ether extractions. Complete with Hot Plate Slide, 8x9 inches; Flask Heater Attachment, 6x3% inches; two Sand Bath Attachments, 4 and 6 inches by 3% inches deep; and with connecting cord and plug. No A B For volts 110 220 Each $42.50 42.50 7515. EXTRA HEATING UNITS for No. 7514 4.00 4.00 7518. HEATERS. Electric Immersion Coils, for heating water baths, thermostats, etc., with three heats. Complete with five-foot cord and regulating switch. May be used on either AC or B.C. No A B C Diameter of coil, inches 6% 81/^ 11 Depth of coil, inches 3 4 4% Height from bottom of coil to bottom of handle, inches 9 13 18 Minimum power consumption, watts 110 275 500 Maximum power consumption, watts 440 1100 2000 Each 15.50 22.00 33.00 In ordering, kindly state voltage. 7520. HEATERS, Electric Immersion, Cylindrical form, made of copper and brass, nickel-plated. Diameter of cylinder, % inch; length of heater, 7 inches; weight, % pound; power eon- sumption, 350 watts. Complete with connecting cord, attachment plug and special switch- plug. No A B For volts 110 220 Each 4.50 5.50 7522. HEATERS, Electric Immersion, Portable Disk Type, for use in water baths, paraffine baths, etc.; made of non-corrosive metal throughout. Complete with six feet of connector cord, separable attachment plug, connection plug and through switch. For 110 volt circuit only. No A B C Diameter of disk, inches 3 4 5 Length of handle, inches 7% 8% 9 Power consumption, watts 250 425 660 Number of heats 1 3 3 Shipping weight, pounds 2 3 4 Each 6.00 9.00 9.50 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 307 Nos. 7526-7. Nos. 7524-5. Nos. 7536-40. HEATERS, Electric Immersion, DeKhotinsky, for use in water baths, incubators, etc., consist- ing of two units, contained in non-corrosive metal tubes, connected in parallel. Unless speci- fied in ordering, 230 watt heater containing two 115 watt units will be sent. Selection may be made from the list of units given under Nos. 7526 and 7527. No A B C D Length of heater tubes, inches 8 12 18 24 For 110 volts $12.00 12.50 13.00 13.50 For 220 volts 13.00 13.50 14.00 14.50 7524. 7525. 7526. 7527. 7528. 7536. 7538. 7540. 7542. UNITS, DeKhotinsky Standard Heating, for use in Nos. 7524 and 7525 Electric Heaters, of Chromel wire wound on lavite. They can be easily installed, requiring only a screw driver for removal and insertion. No A B C D E Wattage 44 60 75 115 140 For 110 volts 1.00 1.00 1.00 1.00 1.00 For 220 volts 1.25 1.25 1.25 1.25 1.25 HEATER, Despatch Flexible Electric, very convenient for use in the laboratory as its flexibil- ity permits it to be wrapped about a bottle, beaker or other object to be heated. Thoroughly insulated and safe to handle. Length unrolled, 16 inches; width, 3% inches; thickness, % inch ; current consumption, 300 watts. For 110 volts only 7.00 HEATERS, Flask, sheet iron, see Flask Heaters. HEATER, Instantaneous Water. Gives hot water in three seconds after the gas is lighted, and in one minute will give sufficient hot water for washing hands. Total height, 9 inches; gas supply required, % inch clear bore pipe and tap; maximum gas consumption 60 cubic feet per hour. Illustration shows the heater on No. 2082 Burner. Heater complete, without burner 7.00 HEATER, Instantaneous Water, same as No. 7536, but with Burner No. 2082 for illuminating gas 9.00 HEATER, Instantaneous Water, same as No. 7536, but with Burner No. 2084 for gasoline gas 10.40 HEATER, Instantaneous Water, specially designed for lavatory, general laboratory and domestic use; it will heat one pint of water per minute from 50°F. to 130°F. or will boil 4 gallons per hour. A pilot light attachment keeps the water in the coil constantly warm when the water is not running and automatically lights the burner when the gas is turned on. Height over 308 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 7562 (in use). No. 7556. A No. 7558. B No. 7572. No. 7570. all, 18 inches; projection from wall, 6 inches; gas supply required, % inch clear bore pipe; maximum consumption per hour, 20 cubic feet of gas. Complete with coupled taps and pilot light $33.00 7544. HEATEK, Instantaneous Water, same as No. 7542, but equipped with burner for gasoline gas 34.00 7546. HEATER, Instantaneous Water, similar to 7542, but larger with twice the capacity. Height over all, 19 inches; projection from wall, 8 inches; gas supply required, % inch clear bore pipe; maximum consumption per hour, 40 cubic feet of gas. Complete with coupled taps and, pilot light 39.00 7548. HEATER, Instantaneous Water, same as No. 7546, but equipped with burner for gasoline gas 40.00 HONES, see Microtome Accessories. HOSE, Rubber, see Rubber Tubing. 7556. HOSE CONNECTOR, brass, for rubber tubing, with thread for ordinary hydrant or kitchen bib. 70 7558. HOSE CONNECTORS, brass, for smooth faucets. For % inch faucet. No A B Each 65 .65 7560. HOSE CONNECTORS, brass, same as No. 7558, for % inch faucet. No A B Each 75 .75 7562. HOSE CONNECTOR, Universal, not threaded, but merely slipped on a faucet and fastened with a chain. Can be quickly attached to any water faucet. The simplest device for attaching filter pumps, stills, water motors, turbines and centrifuges to a common faucet. It is practical, self- tightening and air tight 2.00 7570. HOT PLATES, Electric, round form, three heat, mounted on enameled slate base with regulating switch and furnished with six feet of cord, but without lamp socket plug except Nos. A and B. May be used on either alternating or direct current circuits. No A B C D E Diameter, inches 4% 6 8 10 12 Power consumption, minimum watts 83 150 250 275 325 Power consumption, maximum watts 250 440 735 1100 1300 Each 6.50 9.00 14.00 20.00 28.00 In ordering kindly state voltage. 7572. HOT PLATES, Electric, rectangular form, three heat, with 4 feet of cord but without lamp socket plug. Nos. A and B have three plug switches; C and D have snap switches. No A B C D Size, inches . 9x12 12x18 18x24 4%x24 Power consumption, minimum watts 300 550 1000 150 Power consumption, maximum watts 880 1550 2800 600 Each 22.00 29.00 50.00 16.00 In ordering kindly state voltage. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 309 7578. 7580. 7582. 7589. 7592. No. 7592. No. 7582. 7593. HOT PLATE, Electric, Grid Type, three heat, with heating surface 10%xlO% inches; height of plate, 4% inches. A greater amount of heat may be obtained from this plate than from other forms, as the heating unit is in the open and direct radiation is obtained. Provided with switch giving three heats, consuming 220, 440 and 880 watts; finished in nickel-plate. Shipping weight, 17 pounds. Complete with 7 feet of connecting cord and attachment plug. No A B For volts 110 220 Each $10.00 10.00 HOT PLATE, Electric, Grid Type, similar to No. 7578, but with two burners, giving heating surface 10x20 inches; each burner has a separate three heat switch. Current consumption with left hand burner, 220, 440 and 880 watts; with right hand burner, 375, 750 and 1500 watts. Height of plate, 5% inches; shipping weight, 35 pounds. • No A B For volts 110 220 Each 22.50 22.50 HOT PLATE, Electric, Grid Type, similar to No. 7578, but with three burners giving a heat- ing surface 14x32% inches. Each burner has a separate three-heat switch. Current eon- sumption with left hand burner, 125, 250 and 500 watts; with center burner, 275, 550 and 1100 watts; with right hand burner 375, 750 and 1500 watts. Height of plate, 5% inches; shipping weight, 50 pounds. No A B For volts 110 220 Each 32.50 32.5C HOT PLATE, Electric, Hoskins Type MA-101, for use on either A.C. or D.C., with heating ele- ments of Chromel wire guaranteed to last one year. With top of pressed steel, heavy bent wire legs, and spiral resistance unit. Heat distribution uniform over top. Very useful for evaporating solutions, drying precipitates, etc. Boils one liter of water from cold in 15 min- utes. Diameter, 6 inches; power consumption, 500 watts; maximum temperature, 483°C. or 900°F. Complete with 6 feet of flexible cord and separable attachment plug. No For volts Each EXTRA HEATING UNITS for No. 7578. No Each HOT PLATES, Electric, Hoskins Type MA-111, for use on either A.C. or D.C. 12x12 inches. Requires only 5 amperes at 110 volts and 2% amperes at 220 volts. Heated at center, covering area 5% inches in diameter. Will boil one liter of water placed in the center from cold in 1 hour and 15 minutes. The cooler section around the center is use- ful for slowly evaporating to dryness contents of beakers, etc. Maximum temperature at center, 260°C. (500°F.); at edge, 1219C. (250°F.); power consumption, 500 watts. Complete with 6 feet of twin-conductor flexible cord with separable attachment plug. No A B For volts 110 220 Each 12.00 12.00 EXTRA HEATING UNITS for No. 7592 each 3.00 3.00 A 110 8.00 B 220 8.00 A B 3.00 3.00 Size of plate, 310 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 7596. No. 7596. No. 7602. No. 7610. HOT PLATE, Electric, Hoskins Three Heat, for variable temperatures. Three heats are ob- tainable from parallel windings, each controlled by a snap switch on the front. High heat boils one liter of water from cold in 20 minutes. Size of hot plate, 12x18 inches; maximum temperature on low heat 246°C. (475°F.) ; on medium heat, 315°C. (600°F.) ; on high heat, 400°C. (750°F.); power consumption on low heat, 600 watts; on medium heat, 1200 watts; on high heat, 1800 watts. Mounted on four square steel legs with polished steel top, com- plete with 6 feet twin-conductor flexible cord and separable attachment plug. No. A B For volts 110 220 Each . $40-00 *°-00 7597. EXTEA HEATING UNITS for No. 7596 each 10.00 10.00 7602. HOT PLATES, Electric, Multiple Unit Type, with replaceable units. Can be used interchange- ably on 110 and 220 volts. The method of construction forces heat to the top, providing a higher temperature than is usually attained with hot plates without increased current con- sumptiem. By shifting connections at the rear from the 110 volt to the 220 volt pins, the num- ber of heats obtained on 110 volts is doubled. All sizes give a maximum temperature of approximately 750°F. (400°C.); on medium heat, 600°F. (315°C.); on low heat, 400°F. (205°C.) Made of cast iron with removable cast iron tops. Bases are finished in optical black. No 10 12 22 32 40 Size, inches 12Vtxl2i/i 12%xl2% 18x12*4 24x18 6%xl8 Shipping weight, pounds 50 51 80 135 45 Number of heats 1 3 3 3 3 Power consumption on low heat, watts 352 520 1070 285 Power consumption on med. heat, watts 704 1030 2140 570 Power consumption on high heat, watts.. 1056 1056 1550 3200 860 Each 26.50 30.00 40.00 67.50 25.00 7603. EXTEA HEATING UNITS for No. 7602. Number required 2 2 2 2 4 Each 4.00 4.00 5.50 5.50 3.50 7610. HOT PLATES or Drying Tables, for use with gas. The top is of one piece of steel, with pol- ished surface; the legs and frame are of cast iron. Flame easily regulated Gives an even temperature. No , A B C Size of plates, inches 10x18% 14%xl8% 18%x25V> Number of burners 1 3 3 Eacn 12.50 16.25 26.25 7612. HOT PLATES, same as No. 7610, but for use with gasoline gas. No A B C Size of plate, inches 10x18% 14%xl8% 18%x25V, Each 17.50 23.35 35.00 HOUE GLASSES, see Sand Glasses. CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 311 HYDROMETERS HYDROMETERS FOR GENERAL USE PLAIN HYDROMETER. Regular size, about 12 inches long. Four-ounce size, about 5 inches long. THERMO-HYDROMETER. Regular size, about 14 inches long. Four-ounce size, about 7 inches long. 71)24. 7(526. 7628. 7632. 7634. 7636. 7640. 7641. 7642. HYDROMETERS, Baume, for heavy liquids, highest quality, graduated in about 11 inches. No ................................ A B C D E Range, degrees Bauine .............. 0-10 10-20 20-30 30-40 40-50 Each ............................... $2.50 2.50 2.50 2.50 HYDROMETERS, Bauine, for heavy liquids, highest quality, graduated in about 11 inches. No ............................................................. A B C Range, degrees Baume .................. . ........................ 0-25 25-50 50-70 Each ........................................................... 2.00 2.00 2.00 HYDROMETERS. Baume, for heavy liquids, highest quality, graduated in %° divisions. Length divisions. Length F G 50-60 60-70 2.50 2.50 2.50 ° divisions. Length about 11 inches. No. Range, degrees Baume 0-35 Each 1.65 B 35-70 1.65 in 1° .50 Length, HYDROMETER, Baume, for heavy liquids, medium grade, graduated from 0° to 70 divisions. Length about 11 inches HYDROMETERS, Baume. for light liquids, highest quality, graduated in ifo' divisions, about 11 inches. No A B C D E F G H Range, degrees Baume 90-80 80-70 70-60 60-50 50-40 40-30 30-20 20-10 Each 3.30 3.00 2.50 2.50 2.50 2.50 2.50 2.50 HYDROMETER, Baume, for light liquids, highest quality, graduated from 40° to 10" in %" divisions. Length, about 11 inches 1.65 HYDROMETER, Baume, for light liquids, medium grade, graduated from 100° to 10° in 1° divisions. Length, about 11 inches 50 HYDROMETERS, Specific Gravity Scale, standard, for scientific work requiring highest degree of accuracy. Graduated at 60°F., in 0.001 divisions; mercury weighted. Length, about inches. Each hydrometer lettered as below A 700 to B 760 to C 820 to D . 880 to .760 .820 .880 .940 E 940 to 1.000 F 1.000 to 1.060 G 1.060 to 1.120 H 1.120 to 1.180 I . 1.180 to 1.240 K 1.300 to 1.360 L 1,360 to 1.420 M 1.420 to 1.480 N 1.480 to 1.540 O 1.540 to 1.600 P 1.600 to 1.660 Q 1.660 to 1.720 R 1.720 to 1.780 S 1.780 to 1.850 J 1.240 to 1.300 Set of 19 hydrometers listed above, complete with a special 12-inch floating hydrometer, with thermometer scale in stem reading from 30" to 120°F., in 1° graduations. The special hydro- meter is marked with letters indicating which spindle to use. Set complete in wooden case 109.00 HYDROMETERS, single spindles only of No. 7640 each 5.00 HYDROMETERS, Specific Gravity Scale, for heavy liquids, highest quality, graduated in 0.002 divisions. Length, about 11 inches. No A B C D E Kange 1.000-1.100 1.100-1.200 1.200-1.300 1.300-1.400 1.400-1.500 Each 3.00 3.00 3.00 3.00 3.00 No F G H J K Range 1.500-1.600 1.600-1.700 1.700-1.800 1.800-1.900 1.900-2.000 Each 3.00 3.00 3.00 3.50 3.50 312 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. No. 7660. 7644. HYDROMETERS, Specific Gravity Scale, for heavy liquids, medium grade, graduated in 0.005 divisions. Length, about 11 inches. No A B C D E Eange, gravity 1.000-1.200 1.200-1.400 1.400-1.600 1.600-1.800 1.800-2.000 Each $0.75 .75 .75 .75 1.00 7646. HYDROMETER, Specific Gravity Scale, for heavy liquids, medium grade, graduated from 1.000 to 2.000 in 0.01 divisions. Length, about 11 inches 50 7C51. HYDROMETERS, Specific Gravity Scale, for light liquids, highest quality, graduated in 0.002 divisions. Length, about 11 inches. No A B C D Range, 0.600-0.700 0.700-0.800 0.800-0.900 0.900-1.000 Each 2.75 2.50 2.50 2.50 7652. HYDROMETERS, Specific Gravity Scale, for light liquids, medium grade, graduated in 0.002 divisions. Length, about 11 inches. No A B C D Range, gravity 0.600-0.700 0.700-0.800 0.800-0.900 0.900-1.000 Each 75 .75 .75 .75 7654. HYDROMETER, Special Gravity Scale, for light liquids, medium grade, graduated from 0.700- 1.000 in 0.005 divisions. Length, about 11 inches 50 7658. HYDROMETER, Combined Baume and Specific Gravity Scales, for heavy liquids, ordinary grade, graduated from 0° to 70° Baume in 1" divisions, and from 1.000 to 2.000 specific gravity in 0.01 divisions. Length, about 11 inches 45 7660. HYDROMETER, Combined Baume and Specific Gravity Scales, for light liquids, ordinary grade, graduated from 100° to 10° Baume in 1° divisions, and from 0.600 to 1.000 specific gravity in 0.005 divisions. Length, about 11 inches 45 7664. HYDROMETER, Universal, Combined Baum6 and Specific Gravity Scales for light and heavy liquids, medium grade, graduated from 100° to 10° and 0° to 70° Baume. in 1° divisions; from 0.700 to 1.000 in 0.005 divisions, and 1.000 to 2.000 in 0.01 divisions. Length, about 15 inches 1.25 HYDROMETERS FOR SPECIAL USES HYDROMETERS, Acid, see Hydrometers, Baume. 7670. HYDROMETER, Acid. Specific Gravity Scale, medium grade, for use in Babcock Milk test. Graduated from 1.800 to 1.850 in 0.001 divisions. Length, 6 inches 70 7672. HYDROMETER, Actinometer Scale, ordinary grade, for photographic uses, graduated 0° to 80° in 1° divisions. Length, 5 inches. Complete with test jar in wooden case 35 7674. HYDROMETERS, Alcohol or Spirit, United States Internal Revenue, Per Cent, of Proof Scale, highest quality. Length, about 8% inches. No A B C D E Kange, degrees 0-100 80-120 100-140 130-170 160-200 Graduated in, degrees 1 % % % % Each 2.25 2.25 2.25 2.25 2.25 7676. HYDROMETER, Alcohol or Spirit, Per Cent, by Volume (Tralle) Scale, highest quality. Widely used in determining percentage of alcohol in beer according to the requirements of the Fed- eral government. Graduated from 0° to 5° in ^0° divisions. Length, 8% inches 5.00 7678. HYDROMETER, Alcohol, Proof and Tralle Scales, medium grade, graduated from 100° below to 100° above Proof, and from 0° to 100° Tralle in 1° divisions. Length, about 11 inches .50 7680. HYDROMETER, Alcohol, United States Custom House, Proof and Tralle Scales, medium grade, with enclosed thermometer. Graduations same as No. 7678. Length, about 18 inches. With correction scale 3.00 7684. HYDROMETER, Alkali. Baume Scale, medium grade, graduated from 0° to 60° in 1° divisions. Length, about 11 inches .50 7686. HYDROMETER, Ammonia, Baume Scale, medium grade, graduated from 10° to 50° in %° divi- sions. Length, about 11 inches 50 HYDROMETER, Asphalt, see Nos. 379 and 380. 7690. HYDROMETER, Barkometer Scale, for tanning liquids, highest quality, with enclosed ther- mometer, graduated from 0° to 70° (1,000 to 1.070 specific gravity) in 1° divisions. Length, 13 inches 5.80 7692. HYDROMETER, Barkometer Scale, for tanning liquids, medium grade, graduated from 0° to 65° (1.000 to 1.065 specific gravity) in 1° divisions. Length, about 11 inches 50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 313 No. 7730. No. 7732. No. 7738. 7C96. H Y DROME TEE, Battery, Specific Gravity Scale, medium grade, flat body, graduated from 1.050 to 1.300 in 0.005 divisions. Length, 7 inches $0.90 7698. HYDROMETER, Battery Syringe or Chargometer, Specific Gravity Scale, ordinary grade, grad- uated from 1.1 to 1.3 in 0.005 divisions. Length of hydrometer, 3% inches; length over all, 11% inches. Complete with good quality rubber bulb and glass syringe with unbreakable flexible rubber tip 1.00 7099. HYDROMETER only for No. 7698. Length, 3% inches 45 7702. HYDROMETER. Beer, Balling Scale, highest quality with enclosed thermometer, graduated from 0° to 24° in ^0° divisions. Length, about 17 inches 5.80 HYDROMETER, Benzine, see Hydrometer, Gasoline. 7704. HYDROMETER, Calcium Chloride Salometer, highest quality, for specific gravity of brine. Graduated from 0° to 120* in 1° divisions. Length, about 11 inches 1.65 HYDROMETERS, Condensed Milk, see Nos. 7744 and 7746. 7708. HYDROMETERS, Creosote, Specific Gravity Scale, highest quality, according to the specifica- tions of the American Society for Testing Materials. Graduated to read at 15.5°C. in 0.001 divisions. Length, 9 inches. No A B Range, gravity .*. 1.000-1.080 1.070-1.150 Each '. 3.65 3.65 7651 B. HYDROMETER, Ether, Specific Gravity Scale, highest quality, graduated from 0.700 to 0.800 in 0.002 divisions. Length, about 11 inches 2.50 7714. HYDROMETER. Gasoline. Baume Scale, medium grade, graduated from 40° to 90° in 1° divi- sions. Length, about 11 inches 50 7716. HYDROMETER, Gasoline, Baume Scale, medium grade, graduated from 40° to 90° in 1° divi- sions. Length, 5 inches. Complete with test jar in wooden case 50 For other GASOLINE HYDROMETERS, see Hydrometers, Oil. 7720. HYDROMETER, Glue, Baume Scale, highest quality, graduated from 0° to 35° in %° divisions, for use at 150°F. Length, about 11 inches 1.65 7724. HYDROMETER, Lime Sulphur (Li-Sul-Sprayometer) , Baume and Specific Gravity Scales, me- dium grade, New York and Pennsylvania pattern, for testing lime-sulphur wash used in spray- ing. Graduated from 0° to 38° Baume, in %° divisions, and from 1.000 to 1.350 specific gravity in 0.005 divisions 75 7726. HYDROMETER, Lime Sulphur, same as No. 7724, complete with 12x2-inch glass jar in wooden ease with directions for use 1.00 7730. HYDROMETER, Milk, Lactometer Scale, ordinary grade, graduated from 0° to 120° in 2° divi- sions. Length, about 11 inches .40 7732. HYDROMETER, Milk, Quevenne's Lactodensimeter, medium grade, with enclosed thermometer, graduated from 14° to 42° (1.014 to 1.042 specific gravity) in 1° divisions. Length, about 13 inches . . 3.50 7734. HYDROMETER, Milk, Quevenne's Lactodensimeter, same as No. 7732, but without enclosed ther- mometer .60 7736. HYDROMETER. Milk, Spence's Lactometer, New York State Dairy Commission Pattern, high- est quality, with enclosed thermometer, graduated from 0° to 120° in 2° divisions. Length, about 12 inches. With correction scale and certificate 5.80 7738. HYDROMETER, Milk, Spence's Lactometer, New York State Dairy Commission Pattern, medium grade, with enclosed thermometer, graduated from 0° to 120° in 2° divisions. Length, about 12 inches. With correction scale 3.50 7740. HYDROMETER, Milk, Lactometer, TTnited States Department of Agriculture Dairy Division Pat- tern, Specific Gravity Scale, highest quality, graduated from 24° to 37° (1.024 to 1.037 specific gravity) in J40° divisions. (See Bulletin 134 of the Bureau of Animal Industry, United States Department of Agriculture, page 16.) 5.00 314 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 7754. 7744. HYDROMETER, Condensed Milk, Baume Scale, highest quality, graduated from 0° to 15° in l^o" divisions. Length, about 11 inches $2.50 7746. HYDROMETER, Condensed Milk, Specific Gravity Scale, highest quality, graduated from 1.040 to 1.080 in 0.001 divisions, for use at 142°F. Length, 9 inches 2.50 7750. HYDROMETERS, Oil Testing, Baume Scale, 4 ounce size, highest quality, with enclosed ther- mometer, with scale at bottom reading from 20° to 120°F., for use in 4 ounce sample bottles or small test jar. Length, about 7 inches. Graduated in 1° divisions to read correct gravity at 60°F. No / A B Range, degrees BaumS 10-50 40-90 Each 5.00 5.00 7751. HYDROMETERS, Oil Testing, Baume Scale, 4 ounce size, same as No. 7750, but plain, without enclosed thermometer. No A B Eange, degrees Baume 10-45 45-90 Each 2.50 2.50 7752. HYDROMETERS, Oil Testing, Baume Scale, 4 ounce size, same as No. 7750, but with smaller ranges and finer divisions for very accurate readings when small samples only are available. Graduated in i£° divisions. No A B C D E F G H Eange, degrees Baumei 10-21 19-31 29-41 39-51 49-61 59-71 69-81 79-91 Each 5.60 5.60 5.60 5.60 5.60 5.60 5.60 5.60 7753. HYDROMETERS, Oil Testing, Baume Scale, 4 ounce size, same as No. 7752, but plain, without enclosed thermometer. No A B C D E F G H Bange, degrees Baumei 10-21 19-31 29-41 39-51 49-61 59-71 69-81 79-91 Each 2.35 2.35 2.35 2.35 2.35 2.35 2.35 2.35 7754. HYDROMETER POCKET CARRYING CASE, of nickel-plated metal, for 4-ounce hydrometer. Complete with hydrometer jar and flannel cover for hydrometer 85 7756. HYDROMETERS, Oil Testing, Baume Scale, regular size, highest quality, with enclosed ther- mometer, with scale at bottom reading from 20° to 120°F., for use in 12 or 15-inch hydro- meter jars. Length, about 14 inches. Graduated to read correct gravity at 60°F. No A B C Eange, degrees Baume; 10-100 10-45 45-90 Graduated to, degrees 1 % % Each 5.30 5.00 5.00 7757. HYDROMETERS. Oil Testing, Baume Scale, regular size, same as No. 7756, but plain, without enclosed thermometer. No A B C Eange, degrees Baume 10-100 10-45 45-90 Graduated to, degrees 1 % \b Each 2.75 2.75 2.75 7758. HYDROMETERS, Oil Testing, Baume Scale, regular size, same as No. 7756, but with smaller ranges and finer divisions for more accurate readings. Graduated in 1/4° divisions. No A B C D Eange, degrees Baume 10-40 30-60 50-80 70-100 Each 5.60 5.60 5.60 5.60 7759. HYDROMETERS, Oil Testing, Baume Scale, regular size, same as No. 7758, but plain, without enclosed thermometer. No A B C D Eange, degrees Baume 10-40 30-60 50-80 70-100 Each 2.35 2.35 2.35 2.35 7760. HYDROMETERS, Oil Testing, Baume Scale, regular size, same as No. 7756, but with smaller ranges and very fine divisions for use when greatest accuracy is required. Graduated in i/J0° divisions. No A B C D E F G H Range, degrees Baumei 10-21 19-31 29-41 39-51 49-61 59-71 69-81 79-91 Each 6.10 6.10 6.10 6.10 6.10 6.10 6.10 6.10 7766. HYDROMETER, Salt Salometer, highest quality, graduated from 0° to 100° in 1° divisions for use at 60"F. Length, about 11 inches 1.65 7768. HYDROMETER, Salt Salometer, medium grade, graduated from 0° to 100° in 1° divisions. Length, about 1 1 inches 50 HYDROMETER, Silver Solution, see Hydrometers, Actinometer Scale. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 315 No. 7796. No. 7797. No. 7800. No. 7808. No. 7810. HYDROMETERS, Sugar, Brix Scale, highest quality, graduated in i{0° divisions, for use at "C. Length, about 12 inches. B C 6-12 12-18 2.50 2.50 J K 48-54 54-60 No A Range, degrees Brix 0-6 Each $2.50 No H Range, degrees Brix 42-48 Each 2.50 D 18-24 2.50 L 60-66 E 24-30 2.50 M 66-72 F 30-36 2.50 N 72-78 G 36-42 2.50 O 78-84 2.50 2.50 2.50 7774. 7776. 7780. 7782. 7786. 7790. 7794. 7796. 7797. 7800. 7808. 7810. 2.50 HYDROMETERS, Sugar, Brix Scale, medium grade, graduated in 17% °C. Length, about 11 inches. No Range, degrees Brix 0-30 Each 75 2.50 2.50 divisions, for use at A B C 30-60 60-90 .75 .75 HYDROMETER, Sugar, Brix Scale, highest quality, for waste and wash water. Graduated from — 5° to +5° in 1^0° divisions, for use at 17%°C. Length, about 11 inches 2.50 HYDROMETER, Syrup, Balling Scale, highest quality, for eanners and confectioners. Gradu- ated from 0° to 70° in 1° divisions. Length, about 11 inches 1.65 HYDROMETER, Syrup. Baume Scale, medium grade, graduated from 0° to 50° in 1" divisions. Length, about 11 inches 50 HYDROMETERS, Twaddle Scale, highest quality, graduated in %° divisions. Length, about 11 inches. No 1 2 3 4 5 6 Range, degrees Twaddle 0-24 24-48 48-72 72-100100-134134-180 Each 1.65 1.65 1.65 1.65 1.65 1.65 HYDROMETER, Varnish, Baume and Specific Gravity Scales, highest quality with enclosed ther- mometer, graduated from 80° to 10° Baume in 1" divisions and from 0.666 to 1.000 in 0.005 divisions. Length, 17 inches 5.80 HYDROMETER, Vinegar Solidimeter, Baume Scale, highest quality, graduated from 0" to 6" in %° divisions. Length, about 11 inches 1.65 HYDROMETER JARS, see Cylinders. HYDROMETER, Nicholson, constant volume. Of brass, about 27 em long over all, neatly finished 1.50 HYDROMETER, Nicholson-Fahrenheit, constant volume. Of glass, about 12.5 cm long. 2.00 HYDROTIMETER, Bourdon & Bourdet's, for the determination of hardness of water by means • of soap solution. Consists of a burette on foot with scale of hardness marked on, sample . flask for shaking graduated up to 40 cc, boiling flask with mark at 125 cc, with directions for use 3.60 HYGROMETER, Simple Form, for indicating approximately the amount of moisture in the air. In nickel-plated case 2% inches in diameter and % inch deep, with, beveled plate glass cover and celluloid dial graduated from 30 to 100 per cent 3.00 HYGROMETER, Hair. Scale denotes the humidity of the air without reference to tables. In brass case, 3 inch dial '. $7.50 316 CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. No. 7814. No. 7826. No. 7832. 7814. HYGROMETER, Mason, for determining humidify and dewpoint. Metal scale thermometer of approximate range from 10° to 120°F., mounted with insulating support on a mahogany finish board S1/"^^ inches. Glass cistern and special wick, with complete humidity tables.. . §5.50 7815. CISTERN only for No. 7814 ........................................................... 65 7816. THERMOMETER, Dry Bulb, for No. 7814 ............................................ 2.00 7817. THERMOMETER, Wet Bulb, for No. 7814 ............................................ 2.00 7820. HYGROMETER, Mason, simpler form than No. 7814. Thermometers not raised, mounted on oak board 8%x41/fc inches. With complete humidity tables ............................. 3.00 7821. CISTERN only for No. 7820 .......................................................... 65 7822. THERMOMETER, Dry Bulb, for No. 7820 .............................................. 90 7823. THERMOMETER, Wet Bulb, for No. 7820 ............................................. 90 7826. HYGROMETER, Standard, consisting of two Standard Thermometers (like No. 13720) mounted on a finely polished hardwood back 17x5 inches, metal cistern with wick, and certificate for each thermometer .................................................... $13.50 7827. THERMOMETER, Dry Bulb, for No. 7826 ............................................ 5.50 7828. THERMOMETER, Wet Bulb, for No. 7826 ............................................ 5.50 7832. HYGROMETER (Hygrodeik), an improved form of the Mason Hygrometer. Consists of two thermometers, wet and dry bulbs, mounted upon the outer edge of a chart which has been plotted from new and corrected tables prepared under the direction of the U. S. Weather Bureau. This chart, while complicated in appearance, is very simple and obviates entirely the use of tables for temperatures between 20 and 120 degrees Fahrenheit. Size of instrument 10x7%x3 inches. Full directions furnished with each instrument .................... 13.50 7833. THERMOMETER, Dry Bulb, for No. 7832 ............................................ 3.50 7834. THERMOMETER, Wet Bulb, for No. 7832 ............................................ 3.50 7838. HYGROMETER (Hygrodeik), same as No. 7832, but with chart on German silver, reading from 80° to 180°F ...................................................................... 15.00 7839. THERMOMETER, Dry Bulb, for No. 7838 ............................................ 3.50 7840. THERMOMETER, Wet Bulb, for No. 7838 ............................................ 3.50 7341. CISTERN only for Nos. 7832 and 7838 ................................................. 80 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 317 7845. 7848. 7849. 7852. 7853. 7856. 7857. No. 7872. No. 784S. No. 7880. No. 7874. No. 7876. No. 7878. HYGROMETER, Registering (Hygrograph), for furnishing continuous record of humidity over a period of 24 hours. Complete with charts for one year ". $60.00 CHARTS for Xo. 7844 Per box of 55 2.50 HYGROMETER, Sling Psychrometer, designed for the purpose of obtaining quicker and more accurate results than are possible with the stationary wet and dry bulb instruments. Two special thermometers, carefully selected, are mounted on a nicely finished metal plate provided with a wooden handle and swivel, and a ring for suspending the instrument when not in use. Approximate range 0° to 100°F. in 1° divisions 6.00 THERMOMETERS only of No. 7S48 Each 1.60 HYGROMETER, Sling Psychrometer, Standard Grade. Similar to No. 7848, but with thermom- eters of highest grade, graduated in half degree divisions, and with a copper protecting case 1'i "4 iiic-lu-s long , 11.00 THERMOMETERS only of No. 7852 Each 3.50 HYGROMETER, Sling Psychrometer, Pocket Type, Standard Grade. Similar to No. 7852, but 7 inches long with chain sling and 5-inch thermometer graduated in 1" divisions. Complete with leather carrying case - 13.50 THERMOMETERS only of No. 7856 Each 3.50 7860. HYGROMETER WICK. Silk, fits any of our hygrometers 15 7870. ICE BAG. of heavy canvas, 20x38 cm, for breaking ice 25 7872. ICE CHIPPER for use in quickly chipping ice to small bits of a size convenient for laboratory purposes. Tinned iron frame, wood handle ' 75 7874. ICE CUTTING MACHINE. Height, 15 inches; weight, 14 pounds. Hopper, 4^x6 inches by about 4 inches deep. A compact, simple and strong machine which cuts ice into small diamond shaped pieces with ease and rapidity $9.50 7876. ICE CUTTING MACHINE, with blades which cut the ice into pieces about the size of a pea, Size of opening, 4x6 inches; height, 18 inches; space occupied, 9^x9% inches; weight, 30 pounds 13.00 7878. ICE CUTTING MACHINE, similar to No. 7876, but of larger size, for floor use. Size of opening, 8Hxl2 inches; height, 43^ inches; floor space occupied, 24x17% inches; capacity, 75 to 125 pounds of ice per minute ; weight, 280 pounds 49.00 7880. ICE SHAVER for shaving ice, coarse or fine, as may be desired; of tinned iron with removable steel cutter .60 IGNITION TUBES, see Combustion Tubes; Tubes. 318 CENTRAL, SCIENTIFIC CO., CHICAGO, U. S. A. 7S90. 7891. DeKhotinsky Bimetallic Therms Regulator. (Patent Applied for.) INCUBATORS, ELECTRICALLY HEATED AND REGULATED INCUBATORS, Triple Wall, DeKhotinsky Electrically Heated and Regulated (Patented), with new bimetallic regulator and new system of ventilation providing for greatest possible uni- formity of temperature throughout the incubator chamber. Construction: These incubators are constructed of asbestos board on a steel frame, with three walls. The space between the two outer walls is packed with magnesia-asbestos (magnesia 85 per cent; asbestos 15 per cent). Between the inner walls is an air space, through which the air passes upward from the heating units in the base. Ports are provided in the inside walls of this air space, permitting the entrance of the heated air to the incubator chamber, in which it passes up and out through an opening in the false top. The location of these ports has been carefully and scientifically determined so as to provide a continuous current of heated air to every corner of the inner chamber making the temperature uniform throughout. This feature (patent pending) is peculiar to the DeKhotinsky Triple Wall Incubator, and in- sures a uniformity not possible in electrically heated incubators of any other type. The outer door is double walled and packed with magnesia-asbestos. It is beveled on the edges, making close contact, when closed, with the walls, thus preventing leakage of heat. An inner glass door is provided for inspection of the interior without cooling the contents. Between it and the outer door is a dead air space for insulation purposes. Heating of the incubator is effected by means of four of our standard heating units of Chromel wire wound on lavite. Those heating units are located in the base of the incubator between the two bottoms, with an iron deflector placed over, them to prevent radiation of heat from the units into the inner chamber. Three of these heating units are connected in parallel to the switch contact springs, and may be added to the circuit one at a time as desired. The fourth is connected in circuit with the contact points of the thermo-regulator. These heating units can be easily and quickly replaced from outside the incubator without the necessity of open- ing the door or stopping the operation. Temperature control of the incubator is secured by means of our new bimetallic thermo-regula- tor which is made from invar-brass ribbon, and can be set at any desired temperature from that of the surrounding air up to the maximum heat capacity of the incubator. This range of temperature permits the use of these instruments as incubators, paraffine baths, drying ovens or sterilizers. The precision of action of this thermo-regulator is ^"G. The make-and- bteak contact of the thermo-regulator is located outside the incubator, to prevent the possi- bility of ignition of inflammable gases, developed in the inner chamber when used as a dry- ing oven, which often occurs when the contact is made and broken inside. A pilot lamp on top of the incubator is connected in series with the thermo-regulator, enabling the operator to determine at a glance whether the incubator is regulating. These instruments can be oper- ated on either A.C. or D.C. circuits. Complete with Hubbell receptacle and five feet of flex- ible asbestos covered cord with separable Hubbell attachment plug. No A B C Height inside, inches 10% 14% 19% Width inside, inches 17 Depth inside, inches 6% 11% 14 Shelf space, square inches 91 282 47f> For 110 volts $55.00 90.00 145.00 For 220 volts 57.50 92.50 147.50 T.,r EXTRA HEATING UNITS for Nos. 7830-1, see Nos. 7520-7. CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 319 7898. INCUBATORS, Single Wall, DeKhotinsky Electrically Heated and Regulated (Patented), with new bimetallic thermo-regulator. Construction: The incubator is built of *4-inch asbestos board on a steel frame with a founda- tion of %-ineh asbestos board. To effect the greatest uniformity of temperature possible in an incubator of the single wall type, the heating units are placed between two bottoms, the upper bottom being protected from the direct heat of the units by an iron deflector. Air heated by the units passes back between the bottoms, up through the space between the double back to the upper part of the incubator, and after circulating through the chamber returns to the inter-bottom space by way of an opening in the front part of the false bottom. Two shelves of the grid type are provided which, by means of racks, may be set at any desired height. An inner glass door permits inspection of the interior without cooling the contents. The incubator is mounted on a japanned steel base. Heating of the incubator is effected by means of four of our standard heating units of 115 watts each, three of which are permanently connected to the switch contact springs, and the remaining one — the heat regulating unit — is in circuit with our bimetallic thermo-regulator for automatic control of the desired temperature. The system is fused for protection. Temperature control is effected by means of our new bimetallic thermo-regulator, which is made from invar-brass ribbon, and can be set at any desired temperature from that of the surrounding atmosphere to the maximum heat capacity of the incubator, about 95°C. This range of temperature permits the use of these instruments as incubators, paraffine baths, or inactivation chambers. The precision of action of this thenno-regulator is ^4°C. The make- and-break contact of the thermo-regulator is located outside the incubator, to prevent the possibility of ignition of inflammable gases developed in the inner chamber when used as a paraffine'oven, which often occurs when the contact is made and broken inside. A pilot lamp on top of the incubator is connected in series with the thermo-regulator, enabling the operator to determine at a glance whether the incubator is regulating. These incubators can be oper- ated on either A.C. or D.C. circuits. Complete with two extra cartridge fuses, Hubbell recep- tacle, and 5 feet of flexible asbestos covered cord with separable Hubbell attachment plug. Xo A B Height inside, inches 12 12 Width inside, inches 11 11 Depth inside, inches 9 9 Shelf space, square inches 220 220 For volts 110 220 Each $50.00 52.50 7900. INCUBATORS, Single Wall, DeKhotinsky Electrically Heated and Regulated, of same con- struction as Xo. 7898. but larger, with two doors and with eight 115-watt heating units. With same equipment as No. 7898. No A B Height inside, inches 14 14 Width inside, inches 18 18 Depth inside, inches 12 12 Shelf space, square inches 430 430 For volts 110 220 Each 70.00 72.50 For EXTRA HEATING UNITS for Nos. 7898-7900, see Nos. 7526-7. For EXTRA FUSES for Nos. 7898-7900, see No. 9850. 320 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 7908. Size No. 41. No. 7908. Size No. 1. No. 7908. Size No. 33. Electro-Thermostat of No. 7908. INCUBATORS, Electric, Wood Frame, with electro-thermostatie control. Construction: The walls are constructed of successive layers of transite, tar paper, animal hair, tar paper and five-ply wood, the latter consisting of quarter sawed oak over fibrous chestnut. The No. 1 Incubator, because of its small size, is sheathed with a solid wall of quarter- sawed oak % inch in thickness. The others all have the five-ply construction. By this con- struction, excellent insulation is secured, without danger of warping under the influence of heat or capillary moisture from inside the incubating chamber. The doors are provided with glass for observation of the contents, except in the larger sizes (Nos. 11-41), where an inner door of glass is provided with the entire outer door made of wood. The outer wall of quarter- sawed oak is finished in the natural color and highly polished. Heating is accomplished by means of incandescent carbon filament lamps, which heat quickly and cool quickly. The sizes of these are selected according to the cubic contents to be heated. If specified when ordered, the incubators can be furnished with wire wound electric heaters with pilot lights. Ventilation is provided for by means of two holes in the smaller sizes, one near the bottom through which cold air enters, the other at the top through which the warm air escapes. In the larger sizes, there are four holes for entrance and escape of air, and the lamps are pro- vided with chimneys for the purpose of creating air currents. In this manner, a constant air current is maintained. Regulation of the temperature is effected by means of the electro-thermostat, which consists of a diaphragm of hard rubber and a metal disk riveted together. The difference in the expansion of the hard rubber and metal causes the former to become cup-shaped thus moving forward the center to which a platinum contact is attached. As the temperature is lowered the motion is reversed. By this means contact is alternately made and broken between two platinum points in circuit with the lamps, one attached to the diaphragm, the other to a thumb screw passing through the bridge across the thermostat, thus controlling the temperature. A con- denser is provided by which the electric spark between the contact points is quenched, pre- venting the points from being quickly used up. The thermostat and condenser are mounted on a transite base. TEXTUAL SCIENTIFIC CO., CHICAGO, U. S. A. 321 Nos. 7912-3. No. 7916. INCUBATORS, Electric, Wood Frame, Continued. Each incubator is furnished complete with 6 feet of connecting cord and plug for attachment to any lamp socket, Centigrade thermometer, and wire screen shelves. Shipping weight, Xo Height 30 11 1.3 31 32 3.3 41 inside, inches Width inside, inches Depth inside, inches No. of shelves. Xo. of lamps . . Candle power of lamps. . . . 26 18 18 1 2 16 15 12 - Doors single double single double 7908. 7909. Height < inches Shippin; Ibs. . of stand, i ... r weig] it, , 15 . 20.00 . 20.00 145 72.50 72.50 90 25.00 25.00 38 44.00 44.00 For 110 For 220 volts . volts . 50 18 18 4 2 16 double, inner one di- vided 20 300 150.00 150.00 36 18 3 3 16 30 20 18 .3 2 16 double, double divided in middle 26 18 18 1 16 double 30 36 18 .3 3 .30 20 18 220 165.00 165.00 175 85.00 85.00 32 180 85.00 85.00 16 16 double, double divided in middle 32 32 265 220 180.00 97.50 180.00 97.50 7912. 7913. 7916. For PARAFFINE OVENS of same construction as Xo. 7908 Incubators, see Paraffine Ovens Xo. 10122. INCUBATORS, Electric Compartment, of same construction as No. 7908 but with incubating space divided into compartments, each of which is provided with a finely finished quarter- sawed oak front with drawer pull for removing. The method of heating and temperature con- trol are the same as described under Xo. 7908. Ventilation and circulation of air through the various compartments are provided for by making the drawers of perforated galvanized steel, sliding on steel frames. Depth of each compartment inside, IS Inches; height, 6 inches; width. 5 inches. Each incubator is mounted on an angle-iron support of convenient height, and furnished with 6 feet of connecting cord and plug for attachment to any 110- volt lamp socket and with Centigrade thermometer. No A B C D Xumber of drawers 12 24 36 48 Height outside, inches 42 41 48 55 Width outside, inches 22 42 42 54^ Depth outside, inches 23>i 23% 23% 23% Height of stand, inches 26 26 20 20 For 110 volts. 250.00 350.00 490.00 575.00 For 220 volts 250.00 350.00 490.00 575.00 ELECTRIC HEATING DEVICE for changing a gas heated incubator into an electric, consist- ing of an incandescent lamp, Electro-Thermostat Xo. 1.3756 and condenser mounted together on a transite base with cord and plug attached ready for connection to any 110-volt lamp socket. This outfit can be placed on the bottom of any incubating chamber "with a capacitv not exceeding 3600 cubic inches and the cord run through the hole usually found at the bot- tom of the incubator on the right hand side. If the incubator is water jacketed, the water should be removed to secure the best results. Space occupied by heater, 8x8x4l£ inches high. Weight packed for shipment, 8 pounds. For 110 volts .' 13.75 322 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 7918. ELECTRIC HEATING DEVICE for electrifying small incubators, similar to No. 7916, but smaller, with two special 8 candle power lamps mounted on a %fi inch transite base with thermostat, protected from above by a shelf of transite. Method of installing is the same as for No. 7916. Height of heating device, 3 inches; length, 4V2 inches; width, 5 inches. Complete with attachment cord and plug, for 110 volts $13.75 7920. ELECTRIC HEATING DEVICE for large incubators, consisting of two 16-candle power incan- descent lamps protected by metal chimneys and Electro-Thermostat No. 13756, wired together with attachment plug and cord ready to install. The method of installing is the same as given under No. 7916. This equipment can be used successfully in incubating chambers not exceed- ing 8200 cubic inches in cubical space. Weight packed for shipment, 12 pounds. For 110 volts 20.00 ELECTRIC HEATING PLATES, for use in Incubators No. 7908 and 7909 in place of carbon lamps with chimneys, where a dark chamber is desired. The heater consists of a plate of transite mounted on porcelain legs, on the under side of which are mounted a sufficient num- ber of Heating Units No. 7926D to maintain a temperature of 37y2°C. Units are easily re- movable and replaceable in case of injury. A pilot lamp is mounted in the circuit. No A B C D E F G H J For incubator, No.... 2 3 11 12 1.3 31 32 33 41 For 110 volts 8.25 4.50 6.50 8.25 8.25 8.25 8.25 8.25 8.25 For 220 volts.. 8.25 4.50 6.50 8.25 8.25 8.25 8.25 8.25 8.25 7922. 7923. 7926. ELECTRIC HEATING STOVES and UNITS for electrifying gas heated incubators. These are for permanent installation and should be installed and wired by an experienced electrician. They should be used with Electro-Thermostat No. 13756 for temperature control. They con- sist of resistance wire wound on an insulating medium, and in the case of Nos. A, B and C are mounted on transite base and protected by a perforated metal shield. No. E is intended to be used with clips, such as are used for fuses. No. D can be attached by means of binding posts. All are wound for use on 110 volts. * No Size of heater, inches. Capacity, amperes Becommended use. . . . Each A 14x5x3% % to 3 incubating rooms 12.00 B 9x3 %x3 % to 3 large incuba- tors and incubating rooms 10.00 C 9x2 small incubators 5.00 small and medium sized incubators 1.00 E 1 to iy.2 sterilizers 2.25 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 323 7936. 7937. 7938. 7939. INCUBATORS, WATER JACKETED No. 7936F. INCUBATOES, Triple Wall, constructed of heavy polished copper, reenforced at all points subject to strain. The outer walls are covered with a heavy waterproof insulating material bound at the edges by copper trimmings. The walls are triple in construction, forming an inner water jacket surrounded by an air space. The walls of the water jacket are reenforced to prevent bulging due to the water pressure. The outer door is double walled, with beveled edges cushioned with felt to exclude air. The inner door is of plate glass, separated by a dead air space from the outer door, permitting inspection of the contents without cooling the inner chamber. The bottom of the incubator is made conical in shape to distribute the heat and pre- vent it striking at one point. Two openings in the bottom together with a slide ventilator, permit the control of the heated air. The interiors are furnished with woven wire trays with edges bound with copper, supported by brackets riveted to the sides. Circulation of air is provided for in the incubating chamber by means of a long pipe which runs through the water space, thus preheating the air. The thorough insulation of the incu- bating chamber by means of a water jacket, an air space and a non-conductive outer cover- ing, makes precise regulations of the temperature an easy matter, whether the heat is fur- nished by gas, oil or the electric current. All incubators are supplied with sheet iron bases to protect from drafts, the doors of which have mica windows through which the flame may be observed. Tubulations are provided for thermometer, thermo-regulator, ventilation and filling. A ga<;e gla?s, open at the top, indicates the amount in the water jacket. A stop-cock enables the water to be cut off from the glass in case it is broken, and a faucet is attached for drain- ing the jacket. Incubators may be obtained without any equipment for heating or regulation by those who already possess such apparatus. For gas heating, a Koch safety burner is provided with six feet of metallic tubing, an incu- bator thermometer and a Reichert thermo-regulator, which is connected by a metal tube pass- ing through the air jacket to the burner. The Koch Safety Burner will automatically cut off the gas supply within 15 seconds after the flame is extinguished. For oil heating, an oil lamp is supplied, together with a thermo-regulator which operates a damper controlling the escape of the heat or its admission to the incubator. A thermometer is also furnished. For electric heating, replaceable heating units are furnished together with a thermo-regulator, relay, incubator thermometer and connecting cord and plug for attachment to any lamp sock- et. Either of the above methods of heating and temperature control will maintain a con- stancy of %°C. within the incubating space. These incubators can also be used satisfactorily as raraffine ovens. B C D E F G 19 18 19 19 25 28 18 30 12 18 30 18 U 14 9% 914 18 14 15 30 15 15 30 30 121121 141.25 209.75 105.00 121.00 245.00 182.00 179.75 248.25 120.00 143.00 283.55 220.25 178.25 248.25 142.00 158.00 283.50 220.50 Xo. Height inside, inches. . Width inside, inches... Depth inside, inches — Height of base, inches. Xumber of doors Without heating equipment. . With gas heating equipment . . With oil heating equipment . . With electric heating equip- ment . 101.00 12 9i» 15 1 .5 69.50 8450 106.50 In ordering No. 7939, kindly state voltage and nature of current. 204.00 274.00 158.00 179.75 313.50 249.25 324 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 7950. INCUBATORS, Double Wall, similar in construction to No. 7936, but without air space around the water jacket. With sheet iron base 9 inches high with opening on the side for burner, and with one shelf. Can be used satisfactorily as a parafftne oven. No ". A B Height inside, inches 10 12 Width inside, inches 8 10 Depth inside, inches 8 10 7946. 7947. Without heating equipment $51.00 69.50 7950. 7951. 7000. With gas heating equipment 65.00 84.50 INCUBATOR, Double Wall, round form, for use where only a small number of cultures is han- dled at a time. Made of polished copper with a 2-inch water jacket, covered with an insu- lating material. Two covers are provided, the inner one of glass to permit inspection of the contents. With water gage, stop-cock for draining and perforated tray, mounted on sheet iron base 9 inches high with opening for Bunsen burner. Height inside, 9 inches. Height outside, 12 inches. Diameter inside, 8 inches. Diameter outside, 12 inches. Without heating equipment 22.00 With gas heating equipment 30.00 INCUBATORS, Low Temperature, Electrically Controlled, for gelatine cultures at 20°C., or for use at any other predetermined temperature. Constructed entirely of copper and asbestos board, with no wood casing to warp or decay. The walls are thoroughly insulated to prevent the passage of heat. No running water is used. The internal arrangement provides for a perfect circulation of air and consequent uniformity of temperature throughout the incubat- ing chamber. Equipped with electric thermo-regulator with pilot lamp. Height outside, 28 inches. Height inside, 14 inches. Width outside, 14% inches. Width inside, 12 inches. Depth outside, 16% inches. Depth inside, 12 inches. Height of base, 12 inches. Complete with 6 feet of connecting cord and plug for attaching to lamp socket. Can be used on either A. C. or D. C. circuit. No A B For volts 110 220 Each . 225.00 225.00 CEXTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 325 No. No. 7964. 7964. INCUBATOEa Low Temperature, Thelco, Electrically Controlled, with walls composed of ten distinct layers of wood, porcelain, impervious sheeting, dead air spaces and wool felt. The outside covering is of porcelain, fused on steel, with aluminum trimmings around the doors, edges and corner. The Incubator contains two chambers, an upper for ice and a lower for the water-jacketed working compartment, each with its own outside door. The ice chamber is one-piece porcelain lined, and is equipped with a heavy galvanized ice rack. The capacity of this chamber is about 75 pounds of ice, which will last several days in a warm laboratory. 'The electric heating element, or plate, covers the bottom of the lower chamber and is renio'vable. This heating element is made of asbestos transite, wound with a special resistance wire and can be depended upon to run indefinitely without attention. The working compartment is placed within the lower chamber directly on the heating element. It is a heavy triple-walled cop- per jacket, the space between the walls filled with water, and the arrangement is such that while in use the water is in constant circulation. A constant water level attachment is placed on the outside of the incubator so that water in the walls of the copper jacket is automatically kept at a constant leveL The bimetallic thermostat is located in the top of the working compartment and is regulated by- means of a milled head screw from the outside. A pilot lamp indicates when contact is made and broken. The thermostat can be qnicklv and easily set to give any desired tem- perature between 10"C. and 40'C. The working compartment is provided with a cushioned glass door to allow inspection of the contents of the chamber without exposure to the warm outer air. Complete with two adjust- able shelves, adjustable ventilator, snap switch, and connecting cord and plug ^T° •• '"A B For volte JJQ 220 Eacn $330.00 330.00 7974. INCUBATOR. Opsonic, for maintaining pipettes of blood serum at a temperature of 37*C. Constructed of heavy polished copper with tabulations for thermometer, gas regulator and for filling the bath, and with receptacles for 20 pipettes, numbered in order. A cup 3*6 by 1 inch is provided for holding instruments. Mounted on a sheet iron base, 8 inches high, with opening for Bunsen burner. Type A is provided also with six holes, % inch in diameter in the top to hold test tubes. Without burner or regulator No Height, inches Width, inches Depth, inches Each .".".".".".".".'.'.".'.".".".".' INDUCTION COILS, see Electrical Apparatus. INK. DIAMOND, see Diamond Ink. INK. Drawing. «ee Drawing Ink. A .U - 6 HA B 14 - 4 BUI CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 7984. No. 7990. No. 8000. 7984. INOCULATING NEEDLE, a platinum needle 40 mm long, of No. 28 wire, set in a glass han- dle $0.80 7986. INOCULATING NEEDLE, same as No. 7984, but with 80 mm of No. 27 wire 1.80 7990. NEEDLE HOLDER, Inoculating, of brass, nickel-plated, with screw chuck for holding platinum or nichrome wire from No. 28 to No. 24 inclusive. Length, 160 mm. Without wire.. .25 PLATINUM WIRE for No. 7990, see general heading Platinum Ware. 8000. INSECT BREEDING CAGE, of zinc, glass front, with top, bottom and sides of wire gauze for ventilation. Top and bottom are removable. Size S^xS^xlO inches high 4.00 8001. TRAY of galvanized iron, water tight, for use with No. 8000 Insect Breeding Cage for aquatic insects 50 8004. INSECT BREEDING CAGE, all metal, non-corrosive, folding, easily adjusted. Top and sides of wire gauze for ventilation. Size 12x12x16 inches high 5.00 8010. INSECT NET, with collapsible steel frame IS^xll'/i inches when open, and one piece bam- boo handle 30 inches long 2.50 8012. INSECT NET, similar to No. 8010, but with steel frame measuring 15x14 inches when open and with two-piece jointed handle 48 inches long 3.50 8018. INSECT PINS, Mack, with round yellow heads; very stiff with sharp points, in packages of 100. No 00 0 1 2 3 4 5 6 Per 100 25 .25 .22 .22 .22 .22 .22 .22 Per 1000 2.00 2.00 1.90 1.90 1.90 1.90 1.90 1.90 8020. INSECT PINS, white, with round heads, in packages of 100. No 0 1 . 2 3 4 5 6 Per 100 25 .25 .25 .25 .25 .25 .25 Per 1000 2.00 2.00 200 2.00 200 2.00 2.00 8026. INSECT SPREADING BOARDS, for use in drying insects preparatory to mounting. Consists of two strips of hardwood cleated together leaving a groove in the middle in which the body of the insect is placed while the wings are pinned to the two strips. No A B C Length, inches 12 12% 16Ms Width, inches 4% 3% 7% Each 1.10 1.30 1.50 INTERVAL TIMER, see Clock, Interval. JARS, ALL KINDS JARS, Anaerobic Culture, see Anaerobic Culture Apparatus. JARS, Animal, see Animal Holders. JARS, Aquarium, see Aquarium Jars. 8040. JARS, Battery, cylindrical form, of green glass. No A B C Diameter, inches 4 5 6 Height, inches 5 7 8 Capacity, quarts 1 2 4 Each 20 .25 .40 8042. JARS, Battery, cylindrical form, of clear white glass, frequently used for aquaria and specimen work. No A B C D E Diameter, mm 100 100 125 150 225 Height, mm 100 125 175 200 300 Approx. capacity, cc 1000 1200 2500 4000 14000 Each . .55 .70 1.05 1.25 3.10 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 327 8046. 8054. 8055. 8056. 8057. 8062. 8070. 8071. 8074. No. 8046. No. 8054. No. 8062. No. 8070. No. 8071. No. 8074. For BATTEEY JABS of other sizes and shapes, see general heading Batteries. JARS, Bell Glass, see general heading Bell Jars. JARS, Chidlow's Gas Collection, see Flour Testing Apparatus. JARS, Chidlow Expansion, see Flour Testing Apparatus. JARS, Dressing, with loosely fitting knobbed cover. No A Height outside without lid, mm 100 Diameter outside, mm 100 Each $1.00 JARS, Hydrometer, see Cylinders. JARS, Leyden, see Catalog F of Physical Apparatus. JARS, Mouse, see Animal Jars. JARS, Museum, or Specimen, of clear white glass, with diameter of mouth same as that of body. With glass lid with rings for suspending specimens, rubber gasket for sealing, and metal clamp for fastening lid. Only those sizes shown in heavy type are carried in stock. Other sizes can be furnished on short notice: B 120 115 1.25 C 150 150 1.90 D 210 190 3.00 No A B C D E F G H J K L M Height, without lid, inches 4 6 8 12 6 8 12 18 8 12 15 18 Diam. inside, inches. . 2Vi 2% 21/4 2V4 3% 31/2 3J/2 31/2 5 5 5 5 % 1 1% 1% 21/2 4 6 5y2 8 10 12 Each 96 1.10 1.14 1.25 1.50 1.62 1.90 2.28 2.90 3.42 3.65 3.94 No N P Q R S T U V W X Y Z Height, without lid, inches 8 12 6 8 12 15 18 24 36 12 18 24 Diam. inside, inches.. 6y4 6% 7% 7% 7% 7% 7% 7% 7% 11% 11% 11% Capacity, pints 8 12 9 12 18 20 28 36 56 36 58 80 Each 3.72 4.20 5.40 5.70 6.65 7.20 7.65 8.80 11.45 13.50 17.10 21.40 LIDS only for No. 8054. Diameter, inches 2% 3% 5 6% 7% 11% Each .10 .18 .35 .45 .90 2.25 RUBBER GASKETS only for No. 8054 . . each .10 .18 .62 .70 1.05 2.40 CLAMPS onlv for No. 8054 . . each .45 .55 .75 .95 1.55 2.90 JARS, Museum or Specimen, of clear white glass, wide mouth, with glass stoppers carefully ground in to make air tight seal. Sizes printed in heavy type are carried in stock; other sizes will be furnished on short notice. No A B C D E F G H J K L Diameter of body, inches. . 1% iy2 2 2 o 2% 2% 21/2 3 3 3 Height to shoulder, inches. . 2 3 21/2 3% 5 3% 5 7 4 6 8 Diameter of mouth, inches. 1% 1% 11/2 11/2 11/2 2 2 2 21/2 2!/2 21/2 Height to top of stopper, inches 3% 4!/2 41/2 5% 6% 7 7 9 61/4 81/4 10% Capacity, ounces 1% 21/2 31/2 5 7 8 12 16 12 20 20 Each .44 .47 .50 .55 .62 .65 .75 .80 .82 .94 1.10 No M N P Q R S T U V W Diameter of body, inches. . 3% 33/4 33/4 4% 4% 4i/2 6 6 6 6 Height to shoulder, inches. 6 8 10 5 8 12 7 10 12 15 Diameter of mouth, inches. 3 3 3 3% 3% 31/2 5 5 5 5 Height to top of stopper, inches. . 8% 101/2 121/2 7% 10% 143/4 10 13 15 18 Capacitv, ounces 32 40 56 40 64 98 100 144 168 212 Each 1.25 1.50 1.80 1.55 1.95 2.30 2.75 3.60 3.85 4.50 JARS, Nessler, see Colorimetric Apparatus. JARS, Percolating, graduated in ounces. Capacity to top mark, gallons % % 1 2 Each , 2.00 2.90 4.40 6.50 JARS, Percolating, same as No. 8070, but graduated in cc. Capacity to top mark, cc. 1000 2000 4000 8000 Each 2.00 3.00 4.50 6.70 JARS. Precipitating, of heavy glass with lip. Capacity, pints ?4 % 1 2 4 8 16 24 Each 55 .60 .85 1.15 1.50 1.85 3.30 6.65 328 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8078. No. 8086. No. 8090. No. 8092. No. 8094. No. 8096. No. 8098. No. 8100. No. 8104. No. 8106. No. 8108. JAES, Preparation, with glass covers, see Dishes, Preparation. JABS, Sample, Screw-cap, see Bottles, Sample. 8078. JABS, Sample, glass, with metal screw cap; valuable for samples, etc. Capacity, ounces 2 Per dozen $0.60 4 .65 8086. 8090. JABS, Specie, of glass with metal cover, for collecting gases, storing chemicals, etc. Capacity, quarts 1 2 Each 30 .45 JABS, Specimen, of glass, with knobbed cover loosely fitting. Knob is sunk to permit stack- ing of jars. S 1.10 4 .60 No A B C D E Height, inches 2y2 3% 5 66% Diameter of top, inches 6% 6% 8y2 9% 10% Diameter of bottom, inches 5% 5% 7y2 8% 9% Capacity, pints 2 3 6 9 13 Each 40 .50 1.20 1.50 2.50 8092. JABS, Specimen, of glass, with glass cover provided with rubber ring for sealing. No A B C Height outside, inches. . 5% 7*4 8y2 Diameter of mouth, inches 3% 4% 5% Capacity, quarts 1 2 4- Each 30 .50 .80 8094. JAES, Specimen, of clear glass with cover, clamping device and rubber gasket. No A B C D Height, inches 2y2 3% 3% 5% Diameter, inches 2% 3 3% 3% Capacity, ounces 4% 8 9 14 Each . 15 .20 .25 .30 11% 8% 16 3.25 D 11 7y2 8 2.00 E 4% 41/4 23 .35 8096. JAES, Specimen, Calcutt's, made entirely of glass, so there is no danger of corrosion. A half turn of the cover renders the jar air tight. Capacity, pints 1 2 Each .19 .39 Per dozen 1.90 3.90 JAES, Specimen, Inverted Show, see Bottles, Inverted Show. 8098. JAES, Specimen, Mason's Fruit, with screw-lids and rubber gaskets for sealing. Size, quarts V> 1 2 Each 071/2 .08 .11 Per dozen 75 .80 1.10 8100. JABS, Specimen, Sure Seal, with glass cover, metal clamping device and rubber gaskets. Size, quarts y2 1 Each 15 .16 Per dozen 1.50 1.60 8104. JABS, Staining, Coplin's, for ten 3xl-inch slides, with glass lid each .45 per dozen 4.50 8106. JAB, Staining, Naples, of clear glass, with loosely fitting hemispherical cover. Height, 90 mm; diameter, 35 mm 75 8108. JAB, Staining. Naples, same as No. 8106, but with cork stopper, without glass cover. . .65 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 329 No. F6065. No. 8140. No. 8142. No. 8148. No. 8146. No. 8150. 8112. JABS, Stoneware, with handles and covers for storing ordinary chemicals. Preferable to a gal- vanized iron can for refuse. Capacity, gallons.. y> 1 2 4 6 8 Diameter, inches ". 5 6% 8^4 10% 10% 12 Height, inches • 5% 8 8% 10% 13 15% Each $0.35 .50 .75 1.50 2.00 3.00 8114. JARS, Stoneware, with cover and nickel-plated metal stopcock, for storing distilled water, etc. Capacity, gallons 3 5 8 10 15 Each 2.50 3.25 6.00 10.00 13.00 8116. JAR, Stoneware, for storing distilled water or acids, with ground stoneware stop-cock and water level. Capacity, 50 liters 30.00 8120. JARS, Tumblers, Jelly," with cover, 200 cc capacity per dozen .60 8140. KETTLES, Evaporating, graniteware, tin cover. Manufacturer's rated capacity, quarts 2 4 8 Each 60 .80 1.10 8142. KETTLES, Infusion, double boiler, of graniteware, with tin cover. Manufacturer's rated capacity of inner kettle, quarts 248 Each 1.25 2.30 2.60 KNIFE, for glass cutting, see Glass Tubing Cutters. KNIFE for mixing dough, see No. 5938. 8146. KNIFE, Laboratory, good steel blade 4 inches long; round wood handle. Useful for cutting corks, etc 25 8148. KNIFE, Pocket, one blade, excellent quality steel, iron lined cocoa handle, 4-ineh 90 8150. KNIFE, Pocket, two blades crocus polished, iron lined, stag handle, 4-inch. An excellent all- round knife • 1.50 F6063. KYMOGRAPH. This Kymograph may be used either vertically or horizontally. The drum carrying the smoked paper, on which the tracings are made, is 15 cm in diameter by about 15 cm long and is rotated by means of a strong spring motor, which is enclosed in a heavy iron base. The speed is uniform, and is regulated by means of a magnetic control. Starting, stop- ping and regulation of speed is all done from the outside. The shaft carrying the drum is re- versible, and each end has a clutch, in order to secure two speeds, a slow and a fast, both of which may be varied by means of the magnetic control. Range of slow speeds from one revolution in 18 minutes to one in 55 seconds; of fast speeds from one revolution in 42 seconds to one in 8 seconds. Complete with 100 sheets of gummed glazed paper 52.50 F0069. PAPER, glazed and gummed, for use with No. F6065. Size, 15x48 cm. . .Per 100 sheets .75 330 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8168. POTASS, CHROMIUM SULPHATE CHROME ALUM. +24H2O. No. 8176. No. 8172. 8160. LABELS. Dennison's Gummed, rectangular shape with red border. No 201 205 209 213 217 • Length, mm 64 42 37 30 27 Width, mm 40 34 28 24 20 Per box 08 .08 .08 .08 .08 Per carton of 12 boxes .75 .75 .75 .75 .75 219 38 19 .08 .75 223 21 17 .08 .75 259 33 14 .08 .75 261 52 14 .08 .75 8162. LABELS, Dennison's Gummed, rectangular shape, with red border, in book form, perforated. Size, about 5x9 inches. No 201 205 209 213 217 219 223 Size, mm 45x68 40x50 30x40 28x33 24x32 22x42 19x24 Number of labels in book 225 300 500 750 750 750 1400 Per book $0.25 .25 .25 .25 .25 .25 .25 Per carton of 12 books 2.50 2.50 2.50 2.50- 2.50 2.50 2.50 8164. LABELS, Dennison's Gummed, oval shape with red border. No 229 239 241 Length, mm 42 Width, mm 30 17 Per box 08 .08 .08 Per carton of 12 boxes 75 .75 .75 8166. LABELS, Dennison's Gummed, rectangular shape, large size, with red border, in boxes of 100. No 2001 2002 2003 2004 2005 2006 2007 Size, inches lV2x3% 1x3% 2x4% 1x2% I%x4 I%x4 1%x2% Per box .20 .16 .30 .16 .22 .20 . .16 Per carton of 10 boxes 1.65 1.35 2.50 1.35 2.00 1.65 1.35 8168. LABELS, Dennison's Gummed, rectangular shape, with red border, in rolls, perforated, 1000 labels in a roll. Each roll is contained in special box with slot to permit drawing out labels as needed. Sizes same as in No. 8160. No 205 209 217 Per roll 85 .40 .60 8172. LABEL BOOK, containing labels for the most used chemicals and reagents, each label having name and symbol. Gummed, perforated, and arranged so that they may easily be removed without destroying the book. (Labels should be covered with melted paraffine after being put on the bottle, to protect them from acids, etc.) Book contains about 500 lab?ls. . . . .45 8176. LABELS, Gummed, Microscope Slide, of white paper with light border, 22 mm square, in boxes of 100 per box .10 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 331 No. 8200. No. 8202. No. 8211. 8178. LABELS, Gummed, Microscope Slide, same as No. 8176, but rectangular, 22x15 mm, in boxes of 100 per box .10 8190. LACQUER, Colorless, for preserving polished metal surfaces. In ounce bottles. .Per ounce .30 8192. LACQUER, Gold, in 1 ounce bottles .Per ounce .40 LACQUER BRUSH, see Brush, Lacquer. LACTOMETERS, see Hydrometers. 8194. LADLES, of wrought iron with handle and lip. Useful for fusing metals. Diameter of bowl, inches 2% 4 Each . . ; 35 SO LAMPS, Alcohol, see general heading Burners. LAMPS, Microscope, see Microscope Accessories. LAMPS, INCANDESCENT In selecting incandescent lamps from those listed below, attention should be paid to the fact that the consumption of carbon filament lamps is approximately 3 watts per candle power, while that of tungsten filament lamps is approximately H4 watts per candle power. SI 96. LAMPS, Incandescent, Miniature, tungsten filament, threaded base to fit No. 5124 Receptacle. No A B C Candle power 1 1% 4 Voltage 2V> 3^, 6 Each $0.25 .30 .35 S19S. LAMPS, Incandescent, tungsten filament, Edison base to fit all Edison receptacles and sockets. No A B Candle power 4 6 Voltage 6 8 Each 60 .60 8200. LAMPS, Incandescent, carbon filament, 110-volt, Edison base to fit all Edison receptacles and sockets. No A B Candle power 16 32 Each 28 .50 8202. LAMPS, Incandescent, tungsten filament, 110-volt, Edison base to fit all Edison receptacles and sockets. No A B C Watts 20 25 40 Each 45 .45 .45 8204. LAMPS, Incandescent, tungsten filament, nitrogen filled, 110-volt, Edison base to fit all Edison receptacles and sockets. No A B Watts 75 100 Each 90 1.50 8206. LAMPS, Incandescent, colored glass, carbon filament, 110-volt; natural colors, not dipped; 16 e. p., Edison T>ase to fit all Edison receptacles and sockets. No A B C D E Color amber blue green ruby frosted white Each 80 .50 .55 .55 .45 8208. LAMP, Pocket Flash, for use in store rooms. Vulcanized fiber case with nickel-plated trimmings. Size. l1-.x61-> inches, with tungsten bulb and battery 1.20 8209. BATTERY for" No. 8208, for replacement 30 8210. INCANDESCENT BULB for No. S208, for replacement 13 8211. LAMP, Standard Incandescent, carbon filament, approximately 110 volts, 16 c. p., 64 watts, for stationary use. With certificate of candle power from the Electrical Testing Laboratories. Accuracy of rating, ¥*% 2.70 LAMPS, Standard Incandescent, tungsten filament of special construction to obviate variable cooling of filament when it touches its anchor wires. More satisfactory as light standards than carbon filament lamps. With certificate of candle power from the Electrical Testing Laboratories. Accuracy of rating, ^{0%. In ordering, specify the voltage at which the lamp should be standardized. This may be between 100 and 130 volts. No A B C D E Watts 25 40 50 60 100 8212. LAMPS for stationary use 6.75 6.75 6.75 6.75 7.80 8213. LAMPS for rotating." 6.75 6.75 6.75 6.75 7.80 332 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 8214. No. 8220. No. 8222. No. 8226. No. 8230. No. 8234. 8214. LAMP, DAVY'S SAFETY, as used in mines. Height, about 25 cm $4.00 LANTERNS, Projecting, see Catalog F of Physical Apparatus. 8216. LEAD SHOT for cleaning bottles, etc. Size No 4 6 7 8 11 Per pound 20 .20 .20 .20 .20 F2857. LEATHER BELTING, Round. Diameter, inches % %2 %6 Per foot 10 .12 .18 LECTURE APPARATUS 8220. LECTURE APPARATUS, for Electrolytic Decomposition of Water, simple form with sliding graduated tubes and removable carbon electrodes 3.50 8222. LECTURE APPARATUS for Electrolysis of Water, improved form, with platinum electrodes that may easily be replaced by copper electrodes or by carbon electrodes for electrolysis of hydrochloric acid. (See Nos. 8*238 and 8239.) Complete with support ' 6.80 8223. GLASS PARTS only of No. 8222 3.80 8226. LECTURE APPARATUS, Hoffman's Form, for electrolysis of water, hydrochloric acid, and ammonia, with ungraduated tubes, two stop-cocks and platinum electrodes, mounted on sup- port as shown 11.50 8227. GLASS PARTS only of No. 8226 with platinum electrodes 8.50 8230. LECTURE APPARATUS. Hoffman's Form, same as No. 8226 but with tubes graduated to show volumetric composition. Complete with support 13.50 8231. GLASS PARTS only for No. 8230. 10.50 8234. LECTURE APPARATUS, Hoffman's Improved Form, for decomposition of water, with gradu- ated tubes, glass stop-cocks and removable platinum electrodes, complete with support 13.00 8235. GLASS PARTS only for No. 8234 with platinum electrodes 10.00 8238. CARBON ELECTRODES for use with Nos. 8220, 8222, 8234 and 8268, consisting of two rubber stoppers fitted with carbon electrodes .60 8239. COPPER ELECTRODES, same as No. 8238, but with copper instead of carbon electrodes .60 8240. PLATINUM ELECTRODES, same as No. 8238, but with platinum instead of carbon elec- trodes 2.75 8242. SUPPORT STAND only for Nos. 8222, 8226, 8230 and 8234 with binding posts 3.00 8246. LECTURE APPARATUS, Hoffman's Form, for showing volumetric composition of hydrochloric acid, with two stop-cocks, complete with support, as illustrated 10.80 8247. GLASS PARTS only of No. 8246 5.00 8250. LECTURE APPARATUS, Hoffman's, same as No. 8246, but with platinum electrodes, for dem- onstrating the volumetric synthesis of ammonia and water. Complete with support. . 8.50 8251. GLASS PARTS only of No. 8250, with platinum electrodes 5.50 8254. LECTURE APPARATUS, Hoffman's Eudiometer, similar to No. 8250, with platinum electrodes, two stop-cocks, and graduated arm. Complete with support 13.00 8255. GLASS PARTS only of No. 8254, with platinum electrodes 10.00 8258. LECTURE APPARATUS for Decomposition and Synthesis of Water, similar to No. 8250, but with platinum electrodes in middle of closed tube. Complete with support 11.50 8259. GLASS PARTS only of No. 8258, with platinum electrodes 8.50 8262. LECTURE APPARATUS, Hoffman's Form, for demonstrating the fixed proportions in the com- bination of hydrogen and chlorine to form hydrochloric acid. With glass stop-cock, ground stopper, and support stand 6.50 8263. GLASS TUBE only of No. 8262, with ground stoppers and stop-cock 4.00 Note: — For illustrations of Nos. 8246-62, see next page. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A, 333 No. 8246. No. 8250. No. 8254. No. 8258. No. 8262. No. 8268. No. 8284. No. 816. No. 8288. No. 8292. No. 8290. No. 8294. 8268. LECTURE APPARATUS, Osborne's Form, for electrolysis of water and for study of conduc- tivity of liquids, ionization, electro-plating and electrolysis of water. A simple, substantial form of electrolytic apparatus that can be used to demonstrate the principles involved in the theory of electrolytic dissociation. It consists of an outer U tube with graduated sliding tubes, shot valves, glass plug and platinum electrodes, which are easily replaced by carbon or copper electrodes (Nos. 8238 to 8240). It allows immediate change of liquids, permits the introduction of an indicator, cloth for bleaching, is reaily cleaned, requires least amount of liquids to fill it. Complete as illustrated, on support with binding posts, with instructions for use $11.00 8269. GLASS PARTS only of No. 8268 8.00 8270. SUPPORT STAND* only for No. 8268 3.00 8276. LENS PAPER, Japanese, for cleaning lenses, in sheets 7x11 inches, in packages of 100 sheets. Per package 35 LENSES, Magnifying, see Magnifiers. LETTERS, Steel, see Dies. LEVELING BULBS, see No. 1902. 8284. LEVEL, Bench, Adjustable, with handle and accurately graduated vial. Length, 4 inches; handle and tube nickeled, base japanned 3.30 *2«S. LEVEL, Mechanics', Iron, 12 inches long, ground face and ends, japanned body, double plumb .' 2.00 8290. LEVEL, Mechanics', Wood, ordinary type; 10 to 16 inches long. Oval top plate, two side views 50 8292. LEVEL, Pocket, Brass, ground flat on the base, nickel-plated; 2 inches long. Very useful in mak- ing apparatus .50 8294. LEVEL, Pocket, Iron, japanned, 3^4 inches long 20 816. LEVEL, Round, in brass case, for balance cases, drying ovens, incubators, etc. Diameter, 2.5 cm. 4.00 334 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8342. No. 8344. No. 8346. No. 8348. No. 8306. No. F261. No. 8350. 8296. LEVEL, Round, ' ' Which Way, ' ' of steel, nickel-plated. Diameter, 3.5 cm $0.90 F261. LEVELING SCREWS, in sets of three, permitting the rapid leveling of board or glass plate. Made entirely of metal, the base of which is accurately planed. Base japanned, screw white nickel-plated. Height, 7.5 cm; range of adjustment, 13 mm Pet set 1.65 8306. LIBRARY PASTE, best grade. No A B Style Collapsible Tube 4-ounce Screw-Cap Jar Each .15 .15 MAGNIFIERS 8342. MAGNIFIERS, Doublet, consisting of two piano convex lenses in a metal mount, for use either as a hand magnifier or in dissecting microscopes. No A B C Magnifying power, diameters 6 9 12 Focal distance, mm 41.6 27.8 20.8 Focal distance, inches 1.6 1.1 0.8 Working distance, mm '. 22 15 12 Diameter real field, mm 22 16 11 Each 1.00 1.00 1.00 8344. MAGNIFIER. Engravers' Glass, the standard magnifier for use in counting colonies of bacteria. Magnifying power, 3.5 diameters. (See Public Health Report of the United States Public Health 'Service Vol. XXX, No. 33, August 13, 1915) 1.00 8346. MAGNIFIERS, Linen Testers, extensively used in elementary biology work, and for various other purposes where a small compact magnifier is desired. Folds up into very small space. No A B Diameter of opening, inches V\ % Magnifying power, diameters 10 10 Each 75 .75 8348. MAGNIFIERS, Pocket, in folding mount of rubber and zylonite, very light and durable. No ABC Diameter of lens, mm 18 30 50 Magnifying power, diameters 5 3.5 2 Each ............ 50 .75 1.35 8350. MAGNIFIERS, Pocket, same as No. 8348, but with double lens. No A B C Diameter of lenses, mm 15,20 25,30 37,44 Magnifying power, diameters 5-12 3.5-8 2.5-5 Each .'. 90 1.35 1.80 8352. MAGNIFIERS, Pocket, same as No. 8350, but with triple lens. No A B Diameter of lenses, mm -12, 15, 18 15, 18, 20 Magnifying power, diameters 7-30 4-20 Each . 1.10 1.13 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. 335 No. 8361. No. 8366. No. 8368. No. 8376. No. 8378. No. 8386. 8356. 8360. 8361. 8364. 8366. 8368. 8372 8376. 8378. 8382 8386. MAGNIFIERS. Reading Glasses, with nickeled rim and ferrule, and with black wooden handle. Xo A B C D E Diameter of lens, inches 2 2% 3 4 4% Focus, inches 5 6 7 10 12 Each $0.90 1.10 1.35 1.80 2.25 MAGNIFIERS. Triple Aplanat, the highest type of hand or dissecting magnifier. They are perfectly achromatic and free from distortion, have an extra long working distance, and furnish an unusually large, flat field. Xo Magnifying power, diameters Focal distance, mm Focal distance, inches , Working distance, mm Diameter real field, mm Mounted for use in dissecting microscopes Mounted in folding case for hand use A 9 27.8 1.1 L'4..-, 20 4.25 4.25 B 12 20.8 0.8 18.4 15 4.25 4.25 MAGNIFIER, Tripod, giving a large, clear field and sufficient magnifying power for elemen- tary botanical and zoological studies. The lens is focused by screwing up or down in the metal frame 75 MAGNIFIER. Watchmakers' Glass, double convex lens in vulcanite mounting. Diameter, 25 mm : magnifying power, 3 to 5 diameters .60 MAGNIFIER. Watchmakers' Glass, consisting of two lenses of 12 and 25 mm diameter. The front lens (12 mm) can be removed by unscrewing, thus permitting the use of the rear lens (25 mm). Magnifying powers, 4 and 7 diameters 90 . MAILING TUBES, heavy pasteboa. J, I%xl2 inches Per dozen .35 MALLET, Rawhide, round, 6-ounce 1.10 MALLET, Wood, round, 3-inch face 25 MANOMETERS, see Gages. . MATCHES, Swedish Safety, in packages of 12 boxes Per package .16 MATRASSES, see Blowpipe Apparatus. MATRASS HOLDER, see Blowpipe Apparatus. MAUL, of iron, with wooden face and hickory handle. Length of handle, 2 feet; diameter of head, 3% inches; weight. 6 pounds 1.40 MEASURES, Calipers, see Calipers. 336 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8404. 8390. 8392. MEASURES, Dry, Wood, iron bound. Set of 5 pieces, 1, 2 and 4 quarts, 1 peck, MEASURES, Liquid, Agateware, with spout and handle. Capacity, pints 1 2 Each . .' 40 .50 8394. MEASURES, Liquid, Polished Copper, tinned inside, with spout and handle. bushel. $1.60 Capacity, pints Each 1 1.15 2 1.50 4 .70 4 1.90 8 .80 2.70 8396. MEASURES, Liquid, Tinned Iron, with spout and handle. Capacity, pints '/-i 1 2 4 8 Each 10 .15 .20 .30 .40 8400. MEASURES, Liquid, Metric, polished brass, standard form. Capacity, liters 0.01 0.02 O.Oo 0.1 0.2 0.5 1 2 Each 25 .30 .40 .50 .60 .70 .80 .90 8402. MEASURES, Liquid, Metric. Same as No. 8400. Set of seven pieces, 0.01 liter to 1 liter. 3.00 8404. MEASURES, Liquid, Metric. Same as No. 8400. Set of eight pieces, 0.01 liter to 2 liters. 3.90 Note: "Standard Form" is that in which the diameter equals half the height. MEASURES. Metric Rules, see Scales. MEASURING MICROSCOPE, see Microscopes. MECHANICAL STAGE, sec Microscope Accessories. 8410. MELTING POINT TUBE, Thiele's, of hard glass . 1.00 MERCURY BULBS, see No. 1902. METALLOGRAPHIC APPARATUS BLAST. Hot Air for drying freshly polished specimens, see No. 1388. DESICCATOR CABINET for storing polished specimens, see No. 3790. FURNACES for heat treating, sec general heading Furnaces. 8430. GRINDING MACHINE, Endless Belt Type, for rough grinding, for large or small metal speci- mens. Width of belt, 4 inches; dimensions of flat top of machine, 6x10 inches; intended speed of operation, about 1,000 r.p.m. Complete as illustrated with automatic belt tightener, tight and loose pulleys, belt shifter and three grinding belts of different degrees of fine- ness $35.00 In ordering, kindly state whether alundum or carborundum belts are desired. The former should be used for steel, malleable iron, drop forgings, etc.; the latter for brass, bronze, cast iron and v/rought iron. 8431. EXTRA GRINDING BELTS for No. 8430. No A B Degree of fineness coarse medium Each 70 .70 See note under No. 8430. C fine .70 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 337 No. 8435. GRINDING MACHINE, Reciprocating Type, for fine grinding, designed to replace hand grind- ing with fine emery papers from No. 0 to No. 0000, preliminary to polishing. The machine consists of two carriages which move slowly in a horizontal plane with reciprocating mo- tion. Each carries a glass plate 5x2 inches to which emery papers may be fastened by fil- tered adhesive. Complete with four glass plates covered with special metallographic emery paper of different degrees of fineness. S434. With tight and loose pulleys and belt shifter, for belt drive 65.00 8435. With direct connected motor, with worm gear drive. No A B C D A.C. D.C. For volts 110 220 110 220 Each 115.00 115.00 115.00 115.00 8438. EMERY PAPERS. Metallographic, specially prepared for Metallographie purposes. No 0000 000 00 0 1 1G Per quire 2.30 2.00 1.80 1.75 1.70 1.70 S44i>. HACK SAW. Power, with tension device to produce pressure on the saw during the draw cut. Capacity of vise, 4x4 inches; length of blade, 12 inches; size of pulley, 13x2% inches; speed of operation, 60 to 90 r.p.m.; net weight, 110 pounds; shipping weight, 120 pounds.. 20.00 HARDNESS TESTING APPARATUS, see general heading Hardness Testers. MICROSCOPES. Metallurgical, write for information. PHOTOMICROGRAPHIC APPARATUS for Metallography, write for information. 8496. POLISHING MACHINES. Automatic Spray Type, for the final polishing of metal specimens by means of levigated alumina. The machine consists of a motor mounted in a polished oak cabinet, to which is attached a hard rubber horizontal polishing disk, 6 inches in diameter, covered with special broadcloth. A small bronze pump, driven by the motor, pumps alumina polishing liquid from a reservoir in the cabinet and forces it through the spray nozzle upon the center of the polishing disk. The fineness of the spray is adjustable by a valve. The reservoir can be refilled from the outside. A special stirring device prevents precipitation of the alumina. Dimensions of the cabinet, 22x18 inches. Complete as described with one bottle of polishing liquid. No A B C D A.C. D.C For volts 110 220 110 220 Each $150.00 150.00 150.00 150.00 S497. POLISHING CLOTH COVERS for No. 8496, cut to correct size per six 3.00 338 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8512. No. F781. No. 8510. 8498. LEVIGATED ALUMINA for use with No. 8496, specially prepared for obtaining a correct and rapid finish; in powder form. No A B C For use with steel and hard medium hard soft metals metals metals Per ounce .95 1.60 2.30 PYROMETERS, see general heading Pyrometers. MERCURY STILL, Hulett's, see Distilling Apparatus. 8510. METEOROLOGICAL SET, Universal, a complete set of meteorological instruments suitable for a beginner, and of such a quality as to give satisfaction. The set comprises a 5 inch metal case aneroid barometer, 8 inch boxwood thermometer with F., R. and C. scales, 8 inch maximum and minimum (Six's) thermometer with magnet, 8 inch Mason's wet and dry bulb hygrometer with boxwood scale, 5 inch Howard rain gauge, and a calendar for keeping a record of the instruments in the set. Packed in neatly finished box 30.00 8512. METEOROLOGICAL SHELTER. The latest pattern Weather Bureau Instrument Shelter. (Weather Bureau Bulletin No. 459.) Sufficiently large to hold Barograph or Thermograph and the two instruments shown in the cut. Made of best quality white pine wood, painted three coats lead paint, swing door with lock and key. Complete with screws for mounting. Shipped "knocked down" 35.00 WEATHER FORECAST CHART, see No. 14390. For other Meteorological Instruments, see Anemometers, Barometers, Gages, Hygrometers, Sun- shine Recorders, Thermometers and Weather Instruments. METERS, Gas, see Nos. 6786 and 6956. F781. METRONOME, for counting seconds and fractional parts of a second, etc. In fine mahogany case 5.00 F782. METRONOME. Same as No. F781, but with adjustable bell attachment. The bell may be made to strike every second beat, third beat, fourth beat or sixth beat 7.00 F783. METRONOME, with electrical connection. No. F781 Metronome fitted with mercury cups and binding posts for tracing time on a revolving drum in connection with a time marker. Makes contact at each beat of the pendulum 18.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 339 MICROSCOPES We desire to advise our friends and patrons that we are agents for the celebrated Spencer Micro- scopes, manufactured by the Spencer Lens Company, and carry a complete stock of all Microscopes listed herein. The Spencer Microscopes are of recent design and contain many important features not possessed by any other microscope in the world. The Spencer lenses are guaranteed against all defects. We will be glad to send any one of the Spencer Microscopes to responsible persons for com- parison, grade for grade, with any objective or stand of American or European manufacture, with the utmost confidence that the Spencer will be found to be unsurpassed by any and only equaled by few. We unhesitatingly recommend the Spencer Microscopes as representing better values than any other instrument on the market. No. 8532. Diagram of Side Fine Adjustment "D." 8532. MICROSCOPE. Spencer No. 44, the most popular of all Spencer Microscopes. Many hundred are in daily use in medical, educational and general laboratories. The Body Tube is standard, taking standard objectives and oculars. The Arm is strong and very graceful, fitted with the patented side fine adjustment "D," possessing many exclusive features. It has but two bearing surfaces and three working parts. The patented one-piece construction bearing carries the solid steel screw. This screw, with no less than twenty threads engaged even at the limit of its motion, has a heavy flange, F, working against the lever. L. When the screw is turned in such a direction as to carry F forward, the lever is so swung as to raise the body tube. The reverse motion per- mits the tube to be lowered under the influence of the spring. The focusing buttons at either end of this screw travel laterally and serve as a visible index of the center of the fine adjust- ment action. Steel pins in the heads form positive stops at either end of the excursion. The direction in focusing is the same with both fine and coarse adjustments. One revolution moves the tube 0.2 mm. The Stage, 112x108 mm, is completely covered with hard rubber, vulcanized directly to the stage plate. Distance is 80 mm from optical axis to arm. The Substage is standard quick-screw form. The Down-Swing Condenser Mounting may be supplied at $7.50 additional. Furnished in hardwood cabinet with lock and kev. Xo 44A 44B 440 44D Abbe condenser .... .... .... Xosepiece double .... double Objectives, equivalent focus, mm 16,4 16,4 16,4 16,4 Achromatic oculars. . Iflx lOx 6x. lOx 6x, lOx Each $44.50 49.25 46.25 51.00 44E 44F 44H N. A. 1.20 N. A. 1.20 X. A. 1.20 double double triple 16,4 58.25 16,4 6r, lOx 60.00 16.4.1.8 Oil imm. <">x, lox 90.00 340 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 8536, 8540. No. 8536. No. 8540. MICROSCOPE, Spencer No. 64. A standard microscope for general biology; used in hundreds of laboratories. The Body Tube is our standard, 37 mm in diameter, taking standard objectives and oculars. The Arm and its side fine adjustment "D" are identical with those of Microscope No. 8532. This adjustment is patented, is exceedingly durable, will withstand very hard usage and not develop lost motion. (See description and diagram illustration under No. 8532.) It travels laterally, giving an instant visible index of the position of the adjustment relative to the total excursion. Steel pins in heads of buttons produce an absolute stop at either end of excursion, preventing jamming or binding of screw. There are but two bearing surfaces and three working parts. The main bearing is made of one single piece. One revolution moves the tube 0.2 mm. Adjustment ceases to work when objective comes in contact with slide. The Stage, 112x108 mm, is completely covered with hard rubber, vulcanized directly to the stage plate. Beneath the stage is an iris diaphragm operated by a knurled wheel, 62 mm in diameter. Abbe Condenser is supplied when ordered, and is fitted in a simple spiral focusing substagc ring. Distance is 80 mm from optical center to arm. Furnished in hardwood cabinet, with lock and key. No 64A Abbe condenser Nosepiece Objectives, equivalent focus, mm 16,4 64B double 16,4 64C 16,4 64D double 16,4 64E N. A. 1.20 double 16,4 64F 64H N. A. 1.20 N. A. 1.20 double triple 16,4 Achromatic oculars . . lOx Each $36.00 16,4,1.8 oil imm. 6x, lOx 85.00 lOx 6x, lOx 6x, lOx lOx 6x, lOx 40.75 37.75 42.50 49.75 51.50 MICROSCOPE, Spencer No. 65. This instrument is similar to No. 8536, except for the shape of arm and the type of fine adjustment. It is highly recommended for general laboratory work and is a very high grade microscope at moderate cost. The Body Tube is our standard, taking standard objectives and oculars. The Arm is fitted with the sensitive and accurate lever type fine adjustment. One revolution moves the tube 0.5 mm. The action ceases to work when the objective comes in contact with slide. The Stage, 112x108 mm, is completely covered with hard rubber, vulcanized directly to the stage plate. Distance is 80 mm from optical axis to arm. Beneath the stage is an iris dia- phragm operated by a knurled ring. A Substage Ring, with spiral slot for focusing the Abbe condenser, is supplied when ordered or may be applied at any time without returning the microscope to the factory. An auto- matic device locks the upper iris open when condenser is in place. The standard mirror, 50 mm in diameter, plane and concave, is supplied on the usual swinging mirror bar. Furnished in hardwood cabinet with lock and key. double double No 65A 65B 65C 65D Abbe condenser .... .... .... Nosepiece double .... Objectives, equivalent focus, mm 16,4 16.4 16,4 16,4 16,4 Achromatic oculars . . lOx lOx 6x, lOx 6x, lOx lOx Each 33.00 37.75 34.75 39.50 46.75 65E 65F 65H N. A. 1.20 N. A. 1.20 N. A. 1.20 double 16,4 triple 16,4,1.8 oil imm. 6x, lOx 6x, lOx 48.50 82.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 341 8544. -' S564. 8565. S566. S56 . 8568. 8569. 8570. 8572. 8573. No. 8564. No. 8544. No. 8560. No. 8572. MICROSCOPE, Spencer No. 66. An excellent instrument for general laboratory work. A splendid microscope at moderate cost. The Body Tube is our standard, taking standard objectives and oculars. The Ann is the handle arm type with lever fine adjustment "C. " One revolution of the micro- meter screw moves the body tube 0.5 mm. The action ceases to work when the objective comes in contact with slide. The Stage, 103x95 mm, is completely covered with genuine hard rubber, vulcanized directly to the stage plate. Distance is 60 mm from optical axis to base of arm. The iris diaphragm is operated by a knurled ring just beneath the stage. A Substage King, for attaching and focusing the Abbe condenser by means of a spiral slot, is supplied when the condenser is ordered or may be added at any time. The Mirror is plane on one side, concave on the other, 50 mm in diameter, mounted on a swinging bar. Furnished in hardwood cabinet, with lock an 1 key. No 66A Abbe condenser Nosepiece Objectives, equivalent focus, mm 16.4 titiB double 16,4 66C 16,4 66D 66E 66F 66H X. A. 1.20 X. A. 1.20 X. A. 1.20 double double double triple 16,4 16,4 16,4 Achromatic oculars . . lOx Each $33.00 16.4.1.8 oil imm. 6x, lOx 82.00 lOx 6x, lOx 6x, lOx lOx 6x, lOx 37.75 34.75 39.50 46.75 48.50 MICROSCOPE. Brinell, see Hardness Testers. MICROSCOPE, Demonstration. With the exception of the tube, this stand is made entirely of aluminum, thus making it very light. This, with the convenient handle, makes it superior to all others for handing from person to person during class demonstrations. The objective is accurately and easily focused by a spiral movement which is so arranged that the objective may be securely fastened in any focus. The objective is always in sight, thereby being easier to focus, and to exchange for another. The slide is placed upon the stage as in any other microscope and there is no danger of disturbing the cover glass. Furnished with 8x eyepiece and 16 mm objective 13.50 MICROSCOPE, Dissecting, Barnes, with hardwood polished base, movable glass stage, mirror, and two-lens magnifier. Fine screw and also sliding adjustment. Block is provided with pocket for holding dissecting tools 2.75 MAGNIFIER only of Xo. 8564, without holder 90 HOLDER only of Xo. 8564. with vertical rod *4 inch in diameter 25 MAGNIFIER' AND HOLDER of NO. S564. complete 1.15 BLOCK only of Xo. 8564 with mirror and stage, but without magnifier and holder 1.50 GLASS MIRRORS only of Xo. 8564 each .09 per dozen .90 GLASS STAGES only of Xo. 8564 each 09 per dozen .90 MICROSCOPE. Dissecting, same block as Xo. 8564, fitted with 12x Doublet Magnifier which gives perfect definition 3 QQ Note: — Other size Doublets may be furnished, if desired, in place of the 12x at the same price. HOLDER only of Xn. v"2 for doublet magnifiers 30 342 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 8577-80 (front view), Nos. 8577-80 (rear view). 8577. 8578. 8579. 8580. 8584. 8588. No. 8584. No. 8588. MICROSCOPE, Improved Dissecting. The parts of the block at either side of the mirror are cut out to allow light from the sides to strike the mirror, thus doing away with the neces- sity of the operator facing the source of light in order that the light may strike the mirror. The block is hollow beneath and back of the mirror, forming a convenient receptacle for dis- secting tools and lenses. This is closed by a door which is hinged at the lower edge of the block. This is most convenient because it is not necessary to remove the specimen from the stage or the lens from the holder when a new dissecting tool or lens is wanted. The lens is held in an arm which permits movement from side to side and provides for focusing. A black and white metal background is furnished with each instrument. MICROSCOPE, Dissecting, with 9x Doublet $3.30 MICROSCOPE, Dissecting, with 12x Doublet 3.30 MICROSCOPE, Dissecting, with 9x Triple Aplanat 6.50 MICROSCOPE, Dissecting, with 12x Triple Aplanat 6.50 MICROSCOPES, Spencer Dissecting. An extremely well made, thoroughly serviceable and con- venient instrument at a very moderate cost. It is made with special reference to stability, ease of manipulation and durability. The focusing is accomplished by diagonal rack-and- pinion, moving a solid brass rod, whose bearings provide great steadiness and a very smooth movement of long range, so that lenses of long focus may be used. Two milled pinion heads allow either hand to be used in focusing. An extra large stage is provided, covered with a heavy polished glass plate, 75 mm x 100 mm, easily removed. The jointed lens arm permits the lens to be used over any part of the stage. Plane and concave mirror is furnished. The hand rests are of metal, detachable. In hardwood cabinet. No A Number of lenses 1 Type of lens doublet B 2 doublet C 1 triple aplanat 9 27.8 24.5 14.25 D 2 triple aplanat 6, 12 41.6, 20.8 36.8, 18.4 18.50 Magnifying power, diameters 9 6, 12 Equivalent focus, mm 27.8 41.6, 20.8 Working distance, mm 15 22, 12 Each 10.75 11.75 MICROSCOPES, Spencer Dissecting, similar in construction to No. 8584, with the exception that instead of the rack-and-pinion focusing adjustment it is equipped with a friction sliding tube adjustment. A button at the side of the pillar moves a strong cylindrical lens arm support, whose bearings extend the whole length of the inner surface of the hollow pillar, giving a steady, smooth movement. Without hand rests, in hardwood cabinet. No A Number of lenses 1 Type of lens doublet Magnifying power, diameters. Equivalent focus, mm Working distance, mm Each . 9 27.8 15 9.00 B 2 doublet 6,12 41.6, 20.8 22,12 10.00 C 1 triple aplanat 9 27.8 24.5 12.25 D 2 triple aplanat 6, 12 41.6 20.8 .36.8, 18.4 16.50 8589. METAL HAND-RESTS for use with No. 8588 , per pair .75 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 343 No. F585. No. 8610. No. F586. F584. MICROSCOPE, Measuring, Mounted. A plain microscope without micrometer. Fitted with fixed cross hairs, tube and clamp collar. Diameter of tube, 22 mm. Magnification, about 30 diameters. Complete with No. F591 Support §25.50 F585. MICROSCOPE, Measuring. Same as No. F584, without support 13.50 F586. MICROSCOPE, Measuring, Mounted. Similar to No. F584, but with eyepiece micrometer. This micrometer is of new design and is guaranteed to be of the highest order of workmanship and accuracy. The pitch of the micrometer screw is 0.25 mm, and its range is 10 mm; since the micrometer head is divided into 100 parts it is possible to read to 0.0025 mm at the cross hairs. Since the magnification of the objective is about 3 diameters this is equivalent to a reading of about 0.0008 mm on the object being measured. Total magnification, about 30 diameters. Com- plete with No. F591 Support 45.00 F587. MICROSCOPE, Measuring. Same as No. F586, without support 33.00 F591. MICROSCOPE SUPPORT. A heavy, adjustable support for measuring microscopes. The micro- scope can be held rigidly in any position, as all joints can be tightly clamped. The base is sufficiently heavy to insure the stability required in a microscope used for accurate measure- ments. The top of the base is machined, so as to enable the attaching of stages or other acces- sories. The diameter of the horizontal and vertical arms is the same and the microscope may be clamped in a horizontal position, so as to read a vertical scale. Vertical range about 9 cm; horizontal range about 12 cm. Illustration shows Microscope No. F587 used in connection with the support. Support only, without microscope 12.00 MICROSCOPES, Metallurgical, see Metallurgical Apparatus. MICROSCOPES, Projection, see Catalog F of Physical Apparatus. MICROSCOPE ACCESSORIES (Alphabetically Arranged.) 8610. ABBE SUBSTAGE CONDENSER. In order to secure the best results with objectives of high power, an Abbe Condenser must be used. The condenser illustrated has an aperture N. A. 1.20 and meets all the requirements of practical work. It is fitted with an iris diaphragm beneath to modify the amount of light, and is also provided with a ring beneath the iris to hold a blue glass for cutting out the yellow rays of artificial light; or to hold a center stop which to some extent will provide dark field illumination. The mounting is like the cut for the friction collar substages or is swung on the arm of the down-swing condenser mounting 9.00 8614. CAMERA LUCID A, Abbe's, designed to satisfy the demands of the serious laboratory worker. It has a very large mirror, 70 mm x 105 mm, which is supported on adjustable, graduated mirror bar. " Its unique, compact mounting makes it possible to place the eye sufficiently close to the prism so that the pupil takes in all of the divergent rays coming from the whole of the field of the ocular, making the field appear as large and the object very nearly as distinct as when viewed without the camera. The prism is so mounted that the opening in the silvering can be lowered in the case of the higher power oculars, or raised with the lower powers until it comes to the exact focus of the ocular. The prism can be so centered by 344 CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 8630. No. 8636 No. 8640. No. 8634. CAMERA LUCID A, Abbe's, Continued. two concentric screws that the field is free from color to the extreme edge. The light from it is modified by a series of smoked screens of different densities which may be revolved in and out of line between the mirror and the prism. It is made for the standard size micro- scope tubes, now in use by practically all American and European makers. Complete in hardwood case $20.00 8616. CAMERA LUCIDA, same as No. 8614, with the exception that the prism is permanently cen- tered at the factory and that there is no means for modifying the light from the ocular. The prism is the same size and mounted in a similar way. There are no loose parts to get out of place when the prism is moved in and out of the optical center. Complete in hard- wood case 12.00 8630. EYEPIECES, Huyghenian. In arranging the focal distance of the Spencer eyepieces, the method has now been adopted of marking them with figures that indicate in each case how many times the eye-piece enlarges the objective image, projected the distance of distinct vi- sion (250 mm or* 10 inches). For example, the 4x eyepiece magnifies the objective image four times, and the magnification of the 8x eyepiece will be twice as great under similar condi- tions. A lOx ocular now takes the place of the old 8x and a 5x takes the place of the 4x, the old designation being based on the magnifications of the image projected the distance of the optical tube length, 160 mm. The eyepieces are made to fit the standard tube of the Koyal Microscopical Society. No A Magnifying power, diameters 4 Equivalent focus, mm 62.5 Equivalent focus, inches 2ty Each 1.75 8634. EYEPIECE, Micrometer, with movable scale 5 mm in length, divided into The graduated drum, divided into 100 divisions, moves the scale % mm for each revolution, thus permitting readings to be made to }4oo nim- This instrument has a decided advantage over the filar micrometer in that it is not necessary to move the cross hairs the entire length of the object. Complete with case 30.00 8636. EYEPIECES, Micrometer, with fixed scale, providing a convenient method of using the micro- meter scale. The eye lens is mounted in an adjustable sleeve permitting the scale to be brought into exact focus. Scale graduated to 5 mm in I/JOQ mm divisions. No A Magnifying power, diameters 6 Each 5.00 8640. ILLUMINATOR, Dark Pield, for use on any microscope. The condenser is mounted in a solid piece of brass with slots at the end for the stage clips of the microscope. It permits the use of slides on the top surface. The top surface of the condenser is provided with a little ring by which it may be carefully centered. Direct sunlight may be used. Fairly good results may be obtained by using a Welsbach light, but the best source of light is the electric arc light. No. 8682 Arc Light is especially constructed for such work. Complete in neat case, including special diaphragm for 1.8 mm oil immersion objectives 10.00 ARC LAMP for use with No. 8640, see No. 8682. B 9 50 2 1.75 C (i 40 1% 1.75 ID 8 30 1% 1.75 E 1(1 25 1 1.75 F 12 20 A I 1.75 mm divisions. B 10 5.00 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 345 No. 8656 (shown in use) No. 8656. 8648. ILLUMINATOR, BULL'S-EYE~CONDENSER for the illumination of opaque objects and for throwing parallel rays of light upon the mirror from an artificial source in ordinary work with transparent objects. Mounted as shown. Diameter of lens, 75 mm $8.00 S6oO. IMMERSION OIL, Cedarwood, in 1-ounee vials per vial .36 x<>56. INCUBATOR, Electric, for use on microscope stages. Especially valuable in the Widal test, for the cultivation of bacteria, yeasts, spirochetes and tumor cells, and for the observation of malarial parasites. Dimensions, 3^x2x% inch over all, with incubating chamber 3xlx% inch deep, having a removable glass bottom, consisting of a regular microscope slide. The top is a piece of clear mica with a hole cut through the center through which the lens is passed. A rubber washer is provided for sealing the opening. Complete with heater, thermometer, tem- perature regulator for any temperature from 80° to HOT., cord and special plug for attach- ment to any regular 110-volt electric lamp socket, in velvet lined case 18.00 LAMPS FOR MICROSCOPY 8662. LAMPS, Microscope, Radio, for use with any microscope. Consists of a sheet metal housing, nickeled and highly polished, 6% inches in height, mounted on a jointed stand, permitting adjustment at any angle. Complete with special 40 watt Radio globe with concentrated metal filament, one each Rav Filter Blue and White-Ground, 6 feet of cord and connecting plug. No A B For volts 110 220 Each 8.00 8.50 8663. LAMPS, Microscope, Radio, same as Xo. 8662, but with Daylite Filter instead of Blue Filter. No ". A B For volts 110 220 Each 10.00 10.50 8666. LAMPS. Microscope. Radio, for Darkfleld Illumination, similar to No. 8662, but with special Radio-Nitrogen Globe for high power illumination in dark-field work. Complete with Blue and White Ground Filters, connecting cord and plug. No A B For volts 110 220 Each 10.00 15.50 Note: — No. 8666B includes rheostat for reducing voltage to safe amount for Radio-Nitrogen Globe. 8667. LAMPS, Microscope, Radio, same as No. 8666, but with Daylite Filter instead of Blue Filter. No '. A B For volts 110 220 Each 12.00 17.50 Note: — No. 8667B rheostat. 8670. ADAPTER for Nos. 8662 and 8663, to permit a Radio-Nitrogen Globe to be used for dark-field work 1.50 8671. RADIO GLOBE, 40 watts, 110 volts, for Nos. 8662 and 8663 1.50 ^',72. RADIO GLOBE, 40 watts, 220 volts, for Nos. 8662 and 8663 2.00 8673. RADIO-NITROGEN GLOBE, 100 watts, 110 volts, for Nos. 8666 and 8667 2.00 8674. RHEOSTAT, for use with Radio-Nitrogen Globe No. 8673 on 220 volt circuit 5.00 8675. DAYLITE FILTER for use with Radio Lamps 2.50 8676. BLUE FILTER for use with Radio Lamps 75 8677. WHITE-GROUND FILTER for use with Radio Lamps 50 346 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 8682. 8683. 8684. 8685. 8688. 8689. 8690. 8691. 8694. 8695. 8696. 8697. 8698. 8699. 8700. 3701. 8702. 8703. 8704. No. 8682. No. 8694. LAMP, Hand-Peed Arc, the most powerful light source for microscopical work. It may be run on any house circuit, either A.C. or D.C., using the proper rheostat. The carbons may be moved independently or at the same time. A window is provided for observing the arc. The light rays are focused by means of a condenser in a sliding tube. A blue glass and a ground glass are provided, to fit in a groove in front of the condenser. The lamp is adjustable as to height and angle. Complete with blue and ground glass filters, cord and connecting plug but without rheostat or carbons $18.00 RHEOSTATS for No. 8682, fixed form, 5 amperes. No A B For volts 110 220 Each 7.00 10.00 EXTRA CARBONS for No. 8682 each .06 per dozen .60 DAYLITE GLASS AND ADAPTER, for No. 8682 2.00 LAMP, Microscope, Miniature Electric, small but very efficient, measuring 2x2x3 % inches, low enough to work beneath the substage condenser. It is usually used in this position, it then being necessary to swing the mirror of the microscope to one side. The back and base of the lamp are wood, making its use entirely safe for laying on a polished desk or other such surface. The frame is metal, finished with permanent crystal black which is very durable. The bulb is a 15-watt gas-filled, concentrated filament, and may be used directly on any 110- volt circuit, either direct or alternating. It may be used on 220-volt current with Eheostat No. 8691. A metal reflector behind the bulb concentrates the light and no light can escape except through the single opening. The intensity of illumination is ample for the use of 1.8 mm oil immersion objective and lOx ocular. Complete with five feet of cord and attachment plug with bulb, and blue and ground glasses 4.25 LAMP, Microscope, same as No. 8688, but with Daylite glass 4.75 EXTRA BULBS for Nos. 8688 and 8689 each 1.25 RHEOSTAT for use in series with Nos. 8688 and 8689 on 220-volt circuit 3.00 LAMP, Microscope. Spencer No. 370, adjustable in height and angle, and fitted with standard pear-shaped, gas-filled bulb, usable on any 110-volt circuit. The bulb is used end-on, with a reflector behind it, giving ample illumination for 1.5 mm oil immersion objectives and high power oculars. Very serviceable for illuminating opaque objects and for work with a binoc- ular microscope. Complete with five feet of cord and attachment plug, key socket, and with 75-watt 110-volt blue glass gas-filled Mazda bulb. Finished in durable crystal black . . 9.00 EXTRA BULB for No. 8694, 75-watt 110-volt, blue glass 1.00 LAMP, Microscope, same as No. 8694, but with 100-watt 110-volt blue glass gas-filled Mazda bulb 9.75 EXTRA BULB for No. 8696, 100-watt 110-volt, blue glass 1.65 LAMP, Microscope, same as No. 8694, but with 75-watt 110-volt clear glass gas-filled Mazda bulb, fitted with condenser and with blue and ground glasses 10.00 EXTRA BULB for No. 8698, 75-watt 110-volt, clear glass 90 LAMP, Microscope, same as No. 8698, but with 100-watt 110-volt clear glass gas-filled Mazda bulb, fitted with condenser and with blue and ground glasses 10.5C EXTRA BULB for No. 8700, 100-watt 110-volt, clear glass 1.25 LAMP, Microscope, same as No. 8700, but with Daylite glass 12.50 RHEOSTAT, for use with Nos. 8694 and 8698, on 220-volt circuit 5.00 RHEOSTAT, for use with Nos. 8696, 8700 and 8702, on 220-volt circuit 6.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 347 8708. 8709. 8710. 8711. 8714. 8715. 8716. S717. 8718. S719. 8720. $7 2-2. 8730. 8731. 8734 No. 8708. No. 8714. No. 8722. LAMP, Microscope, Spencer Quadruple, for illuminating several microscopes at the same time. It measures 6x6x9 inches, and is entirely constructed of metal, finished with crystal black which is exceedingly durable. It is fitted with a 100-watt 110- volt Mazda gas-filled bulb, ad- justable in height. A single lamp will supply illumination with entire satisfaction for four microscopes at a distance of three feet. The top of the lamp house reaches a maximum temperature of about 140°F., serving as a convenient place for drying specimen slides or keeping paraffine fluid. Complete with standard pear-shaped Mazda bulb, five feet of attach- ment cord, snap switch and plug, four ground and'f our blue glasses $10.00 LAMP, Microscope, same as No. 8708, but fitted with four disks of Daylite glass 13.00 EXTRA BULB for Xos. 8708-9, 100-watt, 110-volt 1.25 RHEOSTAT for use with Xos. 8708-9, on 220-volt circuit 6.00 LAMP. Microscope. Spencer High Power Mazda, designed to meet the demand for a very strong beam of light without the objections incident to an arc. Equipped with a Mazda gas-filled concentrated filament bulb, an independent silvered glass reflector of the proper curve, and a pair of 4^-inch condensing lenses which throw a converging beam of light out through the cone. May be tilted at practically any angle. An excellent instrument for use with the dark field illuminator, and for photomicrography. This apparatus with an attachable section and projection objective, forms a very compact and efficient stereopticon. Complete as described with 250-watt, 110-volt Mazda bulb 20.00 LAMP, Microscope, same as No. 8714, but with 400-watt 110-volt Mazda bulb 23.00 DAYLITE GLASS AND ADAPTER for Xos. 8714 and 8715 2.00 RHEOSTAT for Xo. 8714, on 220-volt circuit 5.00 RHEOSTAT for Xo. 8715, on 220-volt circuit 6.00 EXTRA BULB for Xo. 8714, 250-watt, 110-volt 4.00 EXTRA BULB for Xo. 8715, 400-watt, 110-volt 6.00 DISTRIBUTING BOX for Microscope Lamps, Spencer Quadruple, designed to meet the demand for using several microscope lamps on a single laboratory table from a single incandescent electric extension. Made of metal, fitted with five porcelain sockets. The current is supplied by attaching extension cord and plug to the top socket. It may quickly and easily be re- moved when the laboratory table is desired for other purposes 6.50 MICROMETER, Eyepiece, a glass disk with finely ruled scale to be laid upon the diaphragm of an ordinary Huyghenian eyepiece, with a 5 mm scale divided into 50 parts (to 0.1 mm) 1.50 MICROMETER! Eyepiece, same as Xo. 8730, but with scale divided into 100 parts (to 0.05 mm) • 1-50 MICROMETER, Stage, for standardizing eyepiece micrometers, consisting of a glass object slide with finelv ruled scale. 1 mm divided into 100 parts 3.00 348 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 8738. No. 8746. No. 8760. 8738. 8746. NOSEPIECES, Eevolving, of the circular type, dustproof. They are valuable accessories when the Microscope is supplied with more than one objective, as they save time and prevent dam- age and loss of objectives. When ordered with the microscope, objectives are so fitted that they are par-focal. No A B Style double triple Each $4.75 6.75 OBJECTIVES, Achromatic, made in accordance with methods first adopted by Professor Abbe by which the complete mathematical formulation of the objective is first perfected, all of its elements clearly determined, such as the actual indices of refraction in the several optical glasses employed, the radii of the curved surfaces, the thicknesses of the lenses and the dis- tances of separation, so that this work of prior calculation does away with all the uncer- tainties of experimental optics. A greater degree of perfection and a much greater uni- formity are thus obtained than it is ever possible to obtain in microscope objectives made in other ways. In these calculations especial consideration is given to securing: flatness of field, critical definition, resolution and long working distance. All objectives are corrected for a tube length of 160 mm and a cover glass thickness of 0.18 mm. Nos. H and J are for oil immersion work. C No Equivalent focus, mm Equivalent focus, about, inches Numerical aperture . . Working distance* with 160 mm tube and lOx eyepiece, mm Diameter of the freal field, mm Each . A 48 0.1 28 6.5 4.75 B 32 1% 0.1 15 4.7 4.75 1) 16 F 4 1 0.25 9.5 3.3 6.00 0.5 1.5 1. 9.75 O.C 9.75 0 4 v, 0.85 0.4(i 0.4 9.75 II 1.8 1.25 0.13 0.2 32.50 3 1.5 1.25 0.10 0.14 50.00 * Working distance is the distance between the front lens and cover glass. t Real field is the diameter of the circular area seen through the microscope and measured in the plane of the object. Magnification Table. Tube length, 160 mm. • Image distance, 250 mm. Objec- tives mm. Initial Majrnifi cation OCULARS Objec- tives mm. 4x 5x 6x 8x lOx 12x 15x 20x 48 2.2 8 11 13 18 22 27 33 44 48 40 2.8 11 14 17 22 28 33 42 56 40 32 4 16 20 24 32 40 48 60 80 32 30-22 2-4.5 4-9 5-12 8-19 10-24 15-?>."i 18-43 20-48 30-70 30-22 25.4 6 24 30 36 48 60 72 90 120 25.4 16 10 40 50 60 80 100 120 150 200 16 12 15 60 75 90 120 150 180 225 300 12 8 20 80 100 120 160 200 240 300 400 8 5 36 144 180 216 288 360 432 540 720 5 4 44 176 220 264 352 440 528 660 880 II 4 3 60 240 300 360 480 GOO 720 900 1200 1 3 1.8 95 380 475 570 760 950 1140 1425 1900 1.8 1.5 109 436 545 654 872 1090 1308 1635 2180 1.5 8760. SLIDES, Microscope, medium thick, 75x25 mm (3x1 inch), made of the best American half- white glass, with ground edges, in boxes of % gross per gross 1.50 8762. SLIDES, Microscope, same as No. 8760, but 75x50 mm, (3x2 inches) per gross 2.00 8764. SLIDES, Microscope, extra thin, 75x25 mm (3x1 inch), of white glass per gross 1.90 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 349 8768. 8776. 8780. 8784. 8788. 8792. 8794. 8798. 8799. 8802. 8804. 8810. No. 8788. No. 8802. No. 8810. SLIDES, Microscope, concave center, 75x25 mm (3x1 inch) per dozen $0.90 SLIDE, Drop Culture or Hanging Drop Slide, 75x25 mm (3x1 inch), with spherical cavity 22 mm in diameter by 3 mm deep, ground in polished plate glass 30 SLIDE, Current, Holman's. A plate glass slip, with two oval cells connected by a very shal- low channel. In use, the cells are partly filled with blood and covered by a thin cover glass. By bringing the finger near one of the cavities,, the air is caused to expand and drive the blood through the channel where it may be observed under very favorable conditions. Com- plete with cover 2.00 SLIDE, Life Box, consisting of two glass plates, one on a metal slip, the other adjusted to it by a sliding sleeve. For examining organisms in fluid. Diameter of cell, 25 mm; maximum depth, 8 mm; slip 32x80 mm 2.50 SLIDE, Siphon, Holman's. Consists of a thick plate glass slip with two shallow oval cavities and a deep groove to hold a small fish or similar object and retain it without undue pressure in a fixed position. Small metallic tubes communicate with the extremity of the deep groove. By means of these tubes water may be siphoned through the slide thus keeping the water supply continuously renewed and enabling the object to be kept under observation for long periods of time. Complete with cover 6.00 SLIDE MOUNTING CELLS, Glass. Kings with finely ground edges, for cementing on micro- scope slides to make cells. No A B C D E Diameter, mm 15 18 18 22 24 Height, mm 3 5 10 9 10 Each 15 .15 .15 .15 .15 SLIDE MOUNTING CELLS, Hard Rubber, similar to No. 8792, furnished in depths from 0.5 to 3mm. Diameter, mm 13 16 19 Each 06 .06 .07 .07 In ordering kindly specify depth as well as diameter. SLIDE BOXES, of white wood, with covers fitting inside, so arranged that when removed the ends of the slides are exposed so that they can be easily removed. Grooved to hold 25 objects, numbered and indexed per dozen .90 SLIDE BOXES, same as No. 8798, but grooved to hold 12 slides numbered and indexed, per dozen 95 SLIDE BOXES, of white wood with covers closely fitting outside, grooved to hold 25 objects, numbered and indexed per dozen 1.10 SLIDE BOXES, grooved to hold 100 slides, cloth covered, with hinged cover and catch, each .50 SLIDE CABINET, Minot's Metal, very compact, occupying much less space than a wooden cabinet and affording much better protection against fire. It is strongly made of metal throughout, neatly finished on the outside in maroon-colored japan with bronze stripes. The inside finish is in black japan. It contains 30 japanned metal trays, each holding 24 glass slides, 75x25 mm. The trays are provided with convenient knobs and with card-holders. The cabinet is furnished with a good brass lock and measures 36.3 cm in height, 32.5 cm in depth and 17.5 cm in width, outside. Complete with 30 trays 25.00 350 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8858. No. 8818. No. 8820. 8816. SLIDE COVER GLASSES, made of the best white glass, uniform in thickness, put up in boxes of % ounce each. Shape. •Thickness Dimensions. Price No. mm inches Per oz. Squares 1 0.13-0. 17 1/^oo'1/lso In ordering 1.20 Squares 2 0.17-0.25 Mso'Woo specify size desired, 1.05 Squares 3 0.25-0. 50 VLOO-%O whether 15 mm. 1.00 Circles 1 0.13-0.17 (%"), 18 mm (%"), 1.50 Circles 2 0.17-0.25 Wso'^ioo 22 mm ( 7/s"), or 1.35 Circles 3 0.25-0.50 1Aoo4oo 25 mm (1"). 1.30 Eectangular 2 0.17-0 25 22x40 mm (65=1 oz) 1.50 Rectangular 2 0.17-0 25 I'iso-Moo 22x50 mm (60=1 oz.) 1.50 Approximate Number of Covers Per ounce. 34" T4" 1" Circles &4 " % " No 1 296 206 150 116 No 1 362 280 182 142 No 2 234 162 120 92 No. 2 286 195 157 112 No. 3 196 136 100 76 || No. 3 240 166 122 | 93 8818. 8820. 8176. 8178. 8832. 8836. 8838. 8852. 8858. 8862. SLIDE HOLDERS, soe Staining Dishes. SLIDE HOLDER, Basket Form, of nickeled brass, for use in staining a number of slides simul- taneously. Capacity, 12 slides, placed back to back 1.00 SLIDE HOLDER, Multiplex, designed by E. P. Miller of the University of California. Con- sists of a series of hard rubber plates sliding on rods, which can be clamped together by means of a knurled thumb screw. Will take any number of slides up to 26, and can be used in any kind of jar or receptacle 2.00 SLIDE LABELS for glass slides, 22 mm square, in boxes of 100 per box .10 SLIDE LABELS, for glass slides, 22x15 mm, in boxes of 100 per box .10 SLIDE MAILING CASES, of wood, consisting of top, middle and bottom sections, for stacking. No A B C Section top middle bottom Per dozen 10 .10 .10 SLIDE TRAYS, map form, to hold 14 slides each .30 SLIDE TRAYS, map form, to hold 20 slides each .35 STAGE, Warm, Electrically Heated, for use with any microscope to keep the stage constantly at blo.od heat or other temperature. With this Warm Stage, micro-organisms may be ob- served under the microscope in the temperature of their natural habitat. Consists of a cir- cular disk 3% inches in diameter by % inch thick; with heating element, thermometer, and electro-thermostat, which can be adjusted to maintain any desired temperature on the top of the disk. The disk has a %-inch hole in the center, over which the regular microscope slide may be placed. Complete with cord and special plug for attachment to any 110-volt lamp socket 12.00 TURN TABLE for ringing mounts. The slide is held on a revolving disk; the application of cement or varnish is accurately made by a brush held above; with self-centering device, de- tachable hand-rest and clips for holding down slides. Diameter of turn table, 88 mm. . 5.00 WARMING TABLE, of copper plate, for drying and mounting. Length, 350 mm; width, 100 mm ; height, 213 mm 1-75 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 351 — •4. 5880. 8886. BM& SSM. 8894. 8896. 8897. 8898. No. 8884. No. 8966. WAEMING TABLE, Electrically Heated and Regulated, for warming slides in mounting paraf- fine sections. Can also be used in fixing and hot staining. Constructed of a block of transite 24 inches long and 6 inches wide, mounted on a metal frame 3 inches high. A series of resistance coils embedded in the transite furnishes the heat, the degree of which is controlled by a thermo-regulator adjusted by a small knurled head at the side. A pilot lamp indicates when the current is on and off. Any temperature can be obtained from 30° to 70°C. Ship- ping weight, 33 pounds. Complete with metal hood to protect slides from dust, thermometer, connecting cord and plug for attachment to any 110-volt lamp socket $35.00 MICROTOMES AND ACCESSORIES MICROTOME, Hand, intended for rapid class work or where expense is the chief considera- tion. The object is placed in a clamp in the upper end of the tube, and is raised through the hole in the glass plate by an accurately cut screw, which is entirely enclosed and protected from dust and injury. The feed ia accurate and finely graduated. Each division represents 10 microns. The plate at the top over which the knife is drawn is 3 inches in diameter, mak- ing a firm support for the knife without knife 7.50 MICROTOME, Table, for all kinds of sectioning, including the freezing method. The object clamp is placed in a vertically movable socket, held by hardened steel pivot screws in two vertically swinging arms which are similarly attached to the main frame. The movement thus provided for is regulated by a micrometer screw, with graduated disk and index plate. The finest feed is 2^ microns. The knife travels on glass plates set in grooves in the metal. These plates are extra long, so that the microtome knife will not be drawn off from the ends, thereby endangering its edge. When equipped with a freezing attachment, it makes a very satisfactory microtome for frozen section work. (See Nos. 8885 and 8886.) Without knife 15.00 MICROTOME, Table, same as No. 8884, but with No. 8940 Freezing Attachment for Carbon Dioxide 25.00 MICROTOME, Table, same as No. 8884, but with No. 8942 Freezing Attachment for Ether 22.50 MICROTOME KNITE, chisel blade form, with 88 mm cutting edge, for use especially on Nos. >**4 to 8S86 4.00 MICROTOME, Clinical and Diagnostic, for Hand Teed, provided with micrometer screw with graduated or toothed head, each division representing 5 microns of feed. The hinged arm carrying the knife is held rigidly in line by the solid metal frame preventing an uneven or inaccurate cut. Complete with object clamp to take paraffine blocks up to 30x22 mm, but without knife 19.50 MICROTOME, Clinical and Diagnostic, for Hand Feed, same as No. 8892, but with freezing chamber for carbon dioxide with needle valve to control the flow of gas. Will take objects up to 30 mm in diameter without knife or object clamp 24.50 MICROTOME, Clinical and Diagnostic, for Hand Feed, same as No. 8894, but with both paraf- fine clamp and freezing chamber for carbon dioxide without knife 26.50 KNIFE FOR PARAFFINE SECTIONS, for use with Nos. 8892 and 8896, with 80 mm cutting edge 5.00 KNIFE for Frozen Sections, for use with Nos. 8894 and 8896, with 80 mm cutting edge. . 5.00 352 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 8904. No. 8918. 8902. MICROTOME, Clinical and Diagnostic, with Automatic Peed, similar in construction to No. 8892, but with automatic device for moving the feed screw as the knife is returned for the next stroke. Complete with object clamp for paraffme blocks up to 30x22 mm, but without knife $35.00 8904. MICROTOME, Clinical and Diagnostic, with Automatic Feed, same as No. 8902, but with freez- ing chamber for carbon dioxide without knife or object clamp 40.00 8906. MICROTOME, Clinical and Diagnostic, with Automatic Feed, same as No. 8902, but with both paraffine clamp and freezing chamber for carbon dioxide without knife 42.00 KNIVES for Nos. 8902, 8904 and 8906, see Nos. 8897 and 8898. 8910. MICROTOME, Automatic Laboratory, designed to do away with all sliding parts. The feed mechanism is automatic, simple in construction, covered and protected from dust and drip- pings. The microtome may be securely clamped to any laboratory table. It may be set to cut sections of any desired thickness. Each division of the graduated scale marks 5 microns. The extreme ends of the knife rest in carrier, and, as the lever handle moves the swing- ing arms, the knife describes a flattened curve, corresponding to the double movement in free- hand sectioning. By this manner of holding the knife by arms which are not parallel, the entire length of its cutting edge is utilized, insuring uniform wear and permitting the cutting of very large sections. This peculiar motion of the knife makes this microtome pre-emi- nently fitted for cutting frozen sections. Complete with one knife and usual object clamp for paraffine or celloidin, in case 60.00 8912. MICROTOME, Automatic Laboratory, same as No. 8910, but fitted with No. 8940 Freezing Attachment for Carbon Dioxide 70.00 8914. MICROTOME, Automatic Laboratory, same as No. 8910, but fitted with No. 8942 Freezing Attachment for Ether 67.50 For KNIVES for Nos. 8910 to 8914, see No. 8958B. 8918. MICROTOME, Spencer Simplified Rotary, designed to meet the demand for a dependable instru- ment of precision at a moderate price. A high degree of accuracy is attained by following the same principle of construction which is used in the Spencer Eotary Microtome No. 8922. The feed mechanism is independent of the up-and-down movement of the object. It is oper- ated by a micrometer screw, cut two threads to the millimeter, to which is fastened a wheel having 250 notches cut on its periphery. Each notch represents a thickness of two microns in the section. The instrument will cut any thickness up to forty microns in multiples of two. The total excursion of the feed is 30 mm. A crank provides a means for adjusting the object to the knife with extreme delicacy and also for returning the object clamp to the position necessary for starting a new series of sections. When the clamp has reached the extreme for- ward position, the feed mechanism automatically ceases to work. The object clamp holder is moved up and down at the ends of two parallel hinged arms entirely independent of the feed mechanism. The clamp may be rotated on its axis by loosening one of the screws. It regularly takes in a block 28 mm wide and 16 mm thick. There is a provi- sion by which the latter dimension may be increased to 22 mm. The whole instrument is rigidly made and runs extremely easily and quietly. It is finished in crystal black and is supplied in a substantial case. Complete with one No. 8958B Knife with handle and back for sharpening, and with three object disks 75.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A, 353 No. 8022. No. 8925. S922. MICROTOME, Spencer Rotary, intended for the most accurate and careful work. An inclined plane feed, which is independent of the up-and-down movement on the perpendicular support, overcomes the inaccuracies inherent in other rotary microtomes. The provision of an accurate and reliable feed mechanism, combined with the utmost rigidity of parts, make this instru- ment the most precise and accurate for laboratory or research work. Sections may be cut of any definite thickness, each section having the same thickness. The feed mechanism is composed of a rigid bearing, on which the feed block is moved by an accurate screw, cut with two threads to the millimeter; it is -revolved by a ratchet feed wheel with 250 teeth; each tooth represents therefore a movement forward of the object of one micron. The feed is so arranged that it can be set for sections of any thickness, from 1 micron to 60 microns, by turning the knurled button at the back of the case until the number representing the desired thickness appears opposite the indicator at the small opening in the side of the case near the balance wheel. The total excursion of the feed is 37 mm, allowing a sufficient range for cutting a complete series of a very large object without the necessity of a break due to resetting the knife and feed mechanism. The up-and-down stroke of the object clamp is 50 mm which permits the cutting of very large sections and gives sufficient stroke for celloidin cutting. The clamp may be held at its upper limit for orienting or trimming the block by pushing in a pin. The object may easily be rotated. The knife is fastened by two clamps, each of which clamps the knife at the back and along IVt inches of the edge as well. It may be turned to any desired angle, and the clamps may also be moved toward one another to bring them as near to the ribbon as desired to gain addi- tional rigidity. When the clamps are thus drawn together, the knife may be moved so that practically all of the cutting edge can be used before the necessity of resharpening. The adjustment screws provide for knives of different widths. The whole knife support is adjust- able to and from the object, and is very easily and conveniently clamped in any location by a lever connected with an eccentric cam. The whole of the feeding mechanism is covered, protecting the wearing parts from dust and presenting a very neat appearance. The top of the case is hinged to the lower part, permit- ting it to be easily opened. The balanct wheel is grooved, so that the instrument may be run by a motor. The whole microtome is finished in crystal black, alcohol-proof enamel. The smaller parts are heavily nickel-plated. When desired, the microtome is provided with an adjustable knife support which is especially adapted to celloidin sections. The knife holder of this support is adjustable from a horizontal position through 55° upward. Complete with one knife, handle and back for sharpening, and with three object disks $130.00 8923. KJMJ_t'±; HOLDER for Xo. 8922, for celloidin sections 15.00 8924. KNTFE HOLDER, Adjustable, for No. 8922, permitting the entire block carrying the knife to be shifted 1 !•> inches either way from center 10.00 8925. RIBBON CARRIER. Spencer Cylindrical, for use with No. 8922, consisting of an aluminum cyl- inder mounted in an aluminum frame, under the base of which are small rollers, rolling in the direction of the long dimension of the frame. The end of the ribbon adheres to the evl- inder, which is slightly turned by the knurled heads shown in the illustration as the ribbon lengthens. At the same time, the cylinder and frame are gently pushed forward on the rollers to place the ribbon on the cylinder in a long spiral. The cylinder has flanges at the ends so that when it is removed from its bearings and placed on a sheet of paper on the table, the sections of the ribbon are not injured. When in this position each turn of the spiral may be cut and one turn after another, each approximately 8 inches long, may be spread out in order on the paper. The cylinder is 4% inches long, 2% inches in diameter, and mounted so as to bring it as close as possible to the microtome knife 8.00 S926. TABLE fur Xo. S922, complete with motor and speed regulator, all enclosed. Length, 38 inches; width, 26 inches; oak finish. Xo A B C D A.C. D.C. For volts 110 220 110 220 Each 80.00 98.75 75.00 93.75 354 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 8934. No. 8936. No. 8940. No. 8942. MICROTOME ACCESSORIES 8932. BLOCKS, Red Fiber, for holding specimens for sectioning. .No A B C D Size, inches %*%*% %x%x% %x%x% lxlx% Per 100 $3.00 4.00 5.25 8.25 8934. EMBEDDING BOX for Paraffine, consisting of two angle pieces of metal with a metal plate. No ,. A B C Height, mm 10 20 30 Each 75 .75 .75 8936. EMBEDDING TABLE for Paraffine, of cop'per, 400 mm long and 190 mm wide tapering to a point. With removable legs, 213 mm high 2.00 8940. FREEZING ATTACHMENT for Carbon Dioxide, for Nos. 8884 and 8910 Microtomes. Sub- stantially made, easy to operate, and exciedingly efficient. A hard rubber non-conducting ring between the corrugated plate, to which the object is frozen, and the rest of the appara- tus, prevents the conduction of cold away from the specimen, thus saving time and gas. The chamber is provided with a pin like that on the object clamp, which fits into the same socket on the microtome. The chamber is connected with the CO2 cylinder by a flexible copper tube. In operating, the valve at the chamber should first be closed and the valve at the cylinder slightly opened, to admit the gas into the tube. Then, by opening and closing the small valve at the chamber three or four times in quick succession, the tissue is frozen without any waste of gas and without any inconvenience caused by the freezing up of the chamber or the connections. By this method a section may be cut, stained and mounted ready for examina- tion in one and one-half minutes from the time the tissue is put on the chamber. Com- plete with copper tube connections 10.00 8942. FREEZING ATTACHMENT for Ether. Consists of a freezing chamber of hard rubber which so prevents the radiation of the cold that the tissue is quickly frozen. It will freeze tissue 15 mm in diameter and 3 mm thick in one minute, using only 5 cc of ether. The ether is held in the metal tank, which for filling may be unscrewed from the support from which it is suspended. Any excess of ether which does not evaporate is drained back into the metal chamber from which it came. There are no bottles or entangling tubes and no waste of ether. It is simple, compact and efficient. It can be used on any sliding microtome, such as Nos. 8884 and 8910 7.50 8948. HONE, Ezy Edge, 5% inches long by 2 inches wide, a fast, smooth-cutting hone, combining the sharpness of an artificial hone with the softness of the Belgian. With directions for use .75 8950. HONE, Blue-Green, with small rubbing block, 6 inches long 20 8952. PALM OIL SOAP for use with Nos. 8948 and 8950 per cake .15 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 355 Nos. 8958, 8961 and 8962. No. 8968. No. 8992. No. 8978. No. 8994. 8958. KNIVES, Microtome, of selected steel, so ground and tempered as to produce an edge which is not brittle and at the same time is hard enough and tough enough to retain its keenness. Com- paratively easy to sharpen; evenly tempered; broad and heavy. Without handle or back, in velvet case. Xo ." A B C D Cutting edge, mm 50 110 185 250 Each $4.50 6.00 10.00 15.00 8960. KNIVES, Microtome, similar to Xo. 8958, but designed specially for use with Microtome Xo. 8922. Length of cutting edge, 110 mm. Without handle or back; in velvet lined ease. Xo A B For sections celloidin paraf fine Each 7.00 7.00 8961. HANDLE, Ebonized, for use in sharpening Xos. 8958 and 8960 Microtome Knives. The han- dle is provided with steady-pins to hold it in proper position, while the handle-rod is threaded to engage directly with the corresponding thread cut in the knife, and is tightened by means of a milled head. " The metal parts are finely nickel-plated 1.00 8962. HONING BACK for Xo. 8958B Microtome Knife, to be used in order that the knife may rest upon the honing stone at the proper angle when being sharpened. Polished and nickel- plated 1.00 8963. HONING BACK for Xo. 8960 Knives 1.00 8966. KNIFE, Microtome, Chisel Blade, for use on the table microtome, especially where a freezing chamber is used. Cutting edge, 88 mm. The handle is of such size and shape that the knife may be easily held in the desired position 4.00 8968. KNIFE HOLDEB for Safety Razor Blades, of brass, nickel-plated, for use on any microtome which has a knife clamp. The thin edge of the blade projects beyond the upper edge of the holder just enough to keep it as rigid as possible, and at the same time far enough to allow the specimen to pass by the holder after cutting the section 4.00 8972. PITH, for use in cutting sections; in sticks about 100 mm in length and 6 to 12 mm in dia- meter; in packages of about 50 grams per package .10 8978. RAZOR, Section, folding handle, best quality: one side of blade flat, the other side concave: straight edge, hard rubber handle; length of blade, 80 mm. In case 2.30 8986. STROP, Microtome Knife, consisting of a flat strip of wood with handle, on the sides of which are cemented pieces of leather l*i by 11 inches long. One side has been treated with car- borundum powder, the other is left smooth for finishing 1.25 8987. STROP, Microtome Knife, similar to Xo. 8986, but with leather on one side only which has been treated with carborundum. Dimensions. 2*4x15 inches 1.50 STROP. Microtome Knife, same as Xo. 8987, but covered with best shell butt horsehidel 2.25 STROP, Razor, 21x2 inches, of double Russian red leather, with India filled back, corrugated with nickel-plated swivel and handle 1.00 8994. STROPS, Razor, Emerson's, of calf -skin, specially selected for use with* microtome knives and section razors. No A B Length, inches 13% 17V, Each i.oO 2.00 S996. DRESSING for strops per box .20 356 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 9050 and 9052. No. No. 9056. 9058. No. 9066. No. 9068. No. 9072. No. 9076. No. 9078. MILK AND BUTTER TESTING APPARATUS (Arranged Alphabetically.) 9050. ACID BOTTLE, Combined. By tipping the bottle forward and then letting it come back to upright position, the pipette will fill with 17.5 cc of acid $5.00 9052. ACID BOTTLE TRUNNION, convenient for handling No. 9050 Acid Bottle. Base is of wood covered with lead, which is not acted on by sulphuric acid. Bottle automatically returns to position after tipping 2.00 0056. ACID BURETTES. No A B C D Number of charges of 17.5 ce 3 6 12 25 Each 2.25 2.50 2.70 3.35 9058. ACID BURETTES. No A B C Number of charges of 8.8 cc 6 32 25 Each .- 2.50 2.70 3.35 9062. ACID DIPPER, Nans' Style, 17.5 ec 40 9064. ACID DIPPER, Nans' Style, 8.8 cc 40 9066. ACID MEASURE, cylindrical jar with lip, 17.5 ce 15 9068. ACID MEASURE, cylindrical jar with lip, 8.8 ce 15 9072. ACID PIPETTE, Automatic, Farrington's, consisting of a two-neck Woulff bottle, one neck being fitted with a No. 10461 Automatic Pipette, delivering 17.6 cc; the other neck a No. 1382 Double Rubber Bulb complete 5.50 ACID, Sulphuric for Milk Testing. Prices quoted upon application. 9076. ACID TESTER, Marschall, for the accurate determination of the acidity of milk, cream and whey. Exceedingly simple, and equally valuable for the beginner and the expert. Consid- ered a necessity by all first-class butter and cheese makers. Complete with combined bu- rette and bottle for neutralizer, 9 cc pipette, bottle of indicator, and half gallon bottle of neu- tralizer 8.50 9078. ACID TESTER, Nafis', automatic, easy to manipulate, and self-adjusting. The liquid instantly readjusts itself to zero, so that the only reading to be taken in using the apparatus is at the point on the graduated scale where the liquid surface is located after the sample is neutral- ized. Complete as illustrated, with neutralizer, 9 cc pipette, stirring rod, beaker, 2 ounce bottle of indicator and full directions 5.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 357 THE NAFIS I FAULTLESS STIRRING ROD ~ SALT TEST _ No. 9095. No. 9092. No. 9101. No. 9108. No. 9130 No. 560. 9080. STIKRING ROD, Nafis' Faultless, for use in acidity tests. This rod is hollow and contains a piece of wool of the exact color which the sample of milk should have when the acidity test is complete $0.18 ACIDOMETEE, see general heading Hydrometers. APRONS, see general heading Aprons. 9084. ALKALINE TABLETS, Farrington's, for use in determining the degree of acidity of milk, cream, or whey Per box of 50 tablets .25 560. BALANCE, Cream, Wisconsin Hydrostatic, devised to meet the demand for a simple and cor- rect method of weighing cream into test bottles. It consists of a specially devised brass float, which is placed in a cylinder of water. The instrument is weighted so as to float in a verti- cal position, and has at the top a small pan on which a cream bottle and a 9-gram weight are placed. By means of an adjustable pin point, the point to which the float sinks in water is readily marked. The 9-gram weight is then taken from the pan and the cream to be tested is weighed by dropping it slowly into the bottle with a pipette until the float sinks to the same point it reached with the weight on the pan, when the test bottle will contain exactly 9 grams of cream. Very accurate weighings can be made with this instrument and as there are no bearings to rust it will retain its sensitiveness indefinitely. Complete with metal cylinder, float, and 9-gram weight, but without bottle 5.50 For other BALANCES for Milk and Cream Testing, see general heading Balances. 9088. BOTTLES, Aluminum Screw Cap, for holding samples of cream. With cork washer. One ounce capacity Per dozen .90 9092. BOTTLE, Butter Test, Illinois pattern, a 9 inch bottle for testing 9 gram samples of butter. The neck is graduated for reading up to 90 per cent., and the results obtained compare very favorably with those obtained by chemical analysis .50 9094. BOTTLES, Milk Jars, for composite tests, made of flint glass; will stand much hard usage. Capacity, pints % 1 2 Per dozen 1.00 1.30 1.60 9095. CAPS, Tin, for No. 9004 Milk Jars. Will fit either size, and keep out dirt and impurities. Per dozen .30 BOTTLES, MILK AND CREAM TEST, ORDINARY GRADE 9102. BOTTLE, Milk Test, 6 inch, 18 gram, 8 per cent. Graduated to ^Q P^ ce. t .20 9104. BOTTLE, Milk Test, 6 inch, 18 gram, 10 per cent. Graduated to aj0 per cent 20 9108. BOTTLE, Cream Test, 6 inch, 18 gram, 30 per cent. Graduated to Ms per cent 9110. BOTTLE, Cream Test, 6 iiich, 18 gram, 40 per cent. Graduated to 1 per cent 25 9112. BOTTLE, Cream Test, 6 inch, 18 gram, 50 per cent. Graduated to 1 per cent 25 0114. BOTTLE, Cream Test, 6 inch, 9 gram, 50 per cent. Graduated to % per cent. Direct reading. .30 9120. BOTTLE, Cream Test, 9 inch, 18 gram, 30 per cent. Graduated to %0 per cent 40 9122. BOTTLE, Cream Test, 9 inch, 18 gram, 50 per cent. Graduated to % per cent 40 9124. BOTTLE, Cream Test, 9 inch, 18 gram, 55 per cent. Graduated to % per cent 40 9126. BOTTLE, Cream Test, 9 inch, 18 gram, 100 per cent. Graduated to 1 per cent 60 NOTE: Nine inch Cream Test Bottles are too long for regular Babcock Testers. See No. 9206 Cream Tester. 9130. BOTTLE, Skim Milk, Perfect, 6 inch. Graduated to yloo per cent 70 358 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 33- No. 9170. No. 3850. No. 9174. No. 5254. No. 9172. No. 4192. BOTTLES, MILK AND CREAM TEST, STANDARD The following bottles (Nos. 9136 to 9142) are made in accordance with the specifications formu- lated by the Bureau of Standards, Washington, D. C., and adopted by the Official Dairy In- structors' Association, and by the State of Indiana. 9136. BOTTLE, Milk Test, Standard, 6-inch, 18-gram, 8 per cent. Graduated to i/i0 per cent.. $0.30 9140. BOTTLE, Cream Test, Standard, 6-inch, 9-gram, 50 per cent. Graduated to y2 per cent.. .33 9142. BOTTLE, Cream Test, Standard, 9-inch, 9-gram, 50 per cent. Graduated to % per cent . . .40 The following bottles (Nos. 9146 to 9160) are made in accordance with the specifications formu- lated by the Dairy and Food Commission, Madison, Wis. 9146. BOTTLE, Milk Test, Standard, 6-inch, 18-gram, 10 per cent. Graduated to %0 per cent.. .22 9150. BOTTLE, Cream Test, Standard, 6-inch, 18-gram, 30 per cent. Graduated to V2 per cent.. .33 9152. BOTTLE, Cream Test, Standard, 6-inch, 18-gram, 40 per cent. Graduated to */2 per cent. . .33 9154. BOTTLE, Cream Test, Standard, 7V2-inch, 18-gram, 50 per cent. Graduated to % per cent .40 9156. BOTTLE, Cream Test, Standard, 9-inch, 18-gram, 30 per cent. Graduated to 7710 per cent. .40 9160. BOTTLE, Cream Test, Standard. 9-inch, 18-gram, 50 per cent. Graduated to % per cent.. .40 BRUSHES for cleaning Milk and Cream Test Bottles, see general heading Brushes. BRUSH for cleaning Milk Jars, see Brushes. 3848. CAPSULES, of lead (tin) foil for milk analysis. No A B C Size, inches 2%x% 2%xiy16 3^x^ Per 100 2.50 2.50 2.50 For other CAPSULES, see general heading Capsules. 9170. CASEIN TUBE, Hart's, for estimating amount of casein in milk. To be used in any Babcock Milk Tester 40 9172. CATALASE APPARATUS, for determining the presence and relative amount of catalase in milk, with measuring arm graduated from 0 to 13 cc in i^0 ce divisions. Complete with tube for holding sample, one-hole rubber stopper and glass rod to close hole in stopper. . 3.00 9173. CHARTS, Milk Record, for one week's record of 15 cows, with spaces for both morning and afternoon production, in pounds and tenths per hundred 1.00 0174. CHURNS, Dazey, for family and experimental use. Jars are of glass, so that process can be watched, and are made square to prevent racing of cream and to give double agitation. With aluminum-coated castings, heavily nickeled cap, hardwood turbine dasher, heavily tin-plated dash rod, smooth-running gears, with directions for use. No A B C Total capacity, pints 5 7% 9 Churning capacity, pints 2% 3 % 4 Va Each 1.75 2.25 2.75 . 3850. DISHES, Milk, of aluminum, flat bottom, straight sides. No A B C D Diameter, inches '2 2% 3 4 Height, inches V2 % % 1 Each 20 .30 .36 .40 For other DISHES, see general headings Capsules; Dishes, Evaporating; etc. 4192. DIVIDERS, Plain Brass, for reading graduations on test bottles. Length 4% inches 60 5254. FAT EXTRACTION TUBE, Roehrig, for the determination of fat in milk and milk products, by the Roese-Gottlieb method, adopted as standard by the Association of Official Agricul- tural Chemists 4.50 HYDROMETERS, see general heading Hydrometers. HYDROMETER JARS, see general heading Cylinders. JARS, Sample, see general heading Jars. LACTOMETERS, see general heading Hydrometers. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 359 No. 9194. No. 9200. No. 9204D. Nos. 9210-11. Nos. 8214-15. 9194. MILK TESTER, Babcock, for hand power, with enclosed cut steel spiral gears which run in grease without noise. A clamp is provided for attaching to any table. With seamless brass pockets firmly secured, of the proper depth to contain hot water to submerge the bottles. Complete with two 6 inch, 18 gram, 10 per cent, milk test bottles; one 17.6 ce pipette; one 17.5 cc acid measure; one test bottle brush, and full directions for use 56.50 9196. MILK AND CREAM TESTER, Babcock, for hand power, same as No. 9194, but with two 6 inch, 18 gram, 10 per cent, milk test bottles; two 6 inch, 18 gram, 30 per cent, cream test bottles; one combined 17.6-18 cc pipette; one 17.5 ce acid measure; one test bottle brush, and full direc- tions for use 7>15 9200. MILK AND CREAM TESTER, Babcock, for hand power, same as No. 9194, but four bottle size. Complete with four 6 inch, 18 gram, 10 per cent, milk test bottles; two 6 inch, 18 gram, 30 per cent, cream test bottles; one combined 17.6-18 ce pipette; one 17.5 ec acid measure; one test bottle brush, and full directions for use 8-50 9204. MILK TESTERS, Babcock, for hand power, with solid iron case and hinged cover, cut steel spiral and spur gears and seamless brass pockets, with tinned malleable hangers. _ Gearing and shafts are mounted on a separate frame easily removed for repairs or repacking with grease. Complete with one set of 6 inch, 18 gram, 10 per cent, milk test bottles, one 17.6 ce pipette, one 17.5 ce acid measure, one test bottle brush and full directions. No A B C D Capacity, bottles 6 8 10 Each . .' 16.65 18.50 19.35 20.10 9206. CREAM TESTER, Babcock, for hand power, twelve bottle size, same as No. 9204 Milk Tester, but for 9 inch cream bottles. Complete with twelve 9 inch, 18 gram, 30 per cent, cream test bottles, one 18 ce pipette, one 17.5 cc acid measure, one test bottle brush, and full directions 35.00 MILK TESTERS, Babcock, Electric, same style as Nos. 9194, but mounted directly on a vertical spindle electric motor. Prices include glassware and accessories listed under Nos. 9194 and 9196. No Capacity, bottles For 110 volts, A.C For 110 volts, D.C 9210. 9211. A 2 50.40 50.40 9214. 9215. B 4 51.60 51.60 MILK TESTERS, Babcock, Electric, with same frame and bottle carrier as No. 9204. The motor which is a standard i/i2 h. p. G. E. motor with a speed of 1800 r. p. m., is carried on a separate frame or sub-base and is belt driven requiring no starting device. Prices include glassware and accessories listed under No. 9204. No A B C Capacity, bottles 6 8 10 For 110 volts, A.C 74.80 75.90 78.10 For 110 volts, D.C 74.80 75.90 78.10 360 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 9218. MILK TESTERS, Babcock, International Electric No. 1, for 8 'bottles. This is the regular No. 2670 International Centrifuge, equipped with No. 2685 Head with trunnion rings and cups for 8 six-inch milk bottles. This head is interchangeable with any of those listed in Accessories for International Centrifuge No. 1. (See general heading Centrifuges.) Height closed, 18 inches; open, 28 inches; diameter, 17 inches; shipping weight, about 160 pounds. Complete with 8 trunnion buckets and speed control rheostat but without glassware. No A B C D A.C. D.C. For volts 110 220 110 220 Each $101.40 105.00 97.80 101.40 9220. MHiK TESTERS, Babcock, International Electric No. 2, for 16 bottles, for use with either 6-inch milk bottles or 9-inch cream bottles. This is the regular International Centrifuge No. 2696 equipped with No. 2708 Head with trunnion rings and cups for 16 bottles. This head is interchangeable with any of those listed in Accessories for International Centrifuge No. 2. (See general heading Centrifuges.) Height closed, 28 inches; open, 4'J inches; diameter, 24 inches; shipping weight, about 450 pounds. Complete with 16 trunnion buckets for 6-inch milk bottles, speed control rheostat, and mechanical brake but without glassware. No A B C D A.C. D.C. For volts 110 220 110 220 Each 220.00 220.00 220.00 220.00 9222. MILE TESTERS, Babcock, International Electric No. 2, for 24 bottles. This is a modi- fied form of the No. 2696 International Centrifuge, having a 12-place head which carries double trunnion rings and buckets for all styles of Babcock test bottles. Height closed, 28 inches; open, 40 inches; diameter, 24 inches; shipping weight, about 450 pounds. Complete with trunnion buckets, speed control rheostat, and mechanical brake, but without glassware. No A B C D A.C. D.C For volts 110 220 110 220 Each 180.00 180.00 180.00 180.00 HEATERS, Electric, for use with International Electric Babcock Testers, for heating test bot- tles while in the centrifuge. Operates on the same current as the motor. No A B For Centrifuge No 9218 9220-2 9224. For 110 volts 13.20 14.30 9225. For 220 volts 13.20 14.30 9228. METAL CUP for use with Nos. 9218 and 9220, for 9-inch Babcock bottles 83 9229. TRUNNION RING for No. 9228 55 9236. MILE TESTER, Babcock, Traveling Outfit, consisting of two-bottle Babcock Tester No. 9194, and the following accessories: 2 6-ineh, 18-gram, 10% milk test bottles. 1 floating dairy thermometer. 2 6-inch, 18-gram, 30% cream test bottles. 1 hydrometer jar, 10x1% inches. 2 double neck skim milk bottles. 1 17.5 cc acid measure. 1 cream and milk pipette (17.6-18 cc.) 1 small Quevenne's lactometer. 1 test bottle brush. 1 set directions. Complete in handsomely finished hardwood case with separate compartments for glassware and acid 13.75 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 361 9238. 9240. No. 9240. MILK TESTER, Babcock, Traveling Outfit, same as Tester No. 9200, and two extra milk test bottles . No. 9262. No. 9236, but with four-bottle Babcock . . $15.00 MILK TESTER, Babcock, Traveling Outfit, consisting of No. 9200 Babcock Tester in a handsome leather case as shown in the illustration, 10%xlO%xl0^j inches outside. Complete with the same equipment of glassware and accessories as listed under No. 9238 31.25 9241. 9242. 9243. 9244. 9245. 9246. 9247. 9248. 9249. 9250. 9251. 9252. 9253. 9254. 9255. 9256. 9257. 9262. appears. (451-1) . Repairs for Babcock Milk Testers Nos. 9194 to 9200 and 9236 to 9240. The numbers in parenthesis are the manufacturer's numbers, which in some instances appear on the parts. COVER, with thumb screw and collar. This is the part of the gear case which attaches to the table. (452-1) CASE. This is the front of the gear ease on which the name "Facile" THUMB SCREW. (454H) SWIVEL or collar for thumb screw. (454G) SCREWS for cover. (4541) CRANK only, without handle. (453) CRANK, complete with handle. (454E) WOOD HANDLE for crank. (454D) HANDLE RIVET. (454C) CRANK SHAFT. (454B) TAPER PIN for attaching crank to crank shaft. (454F) GEAR for inner end of crank shaft. (454) WORM SPINDLE, with slot at top for head. (454A) BALL for bearing. (454J) TWO-BOTTLE HEAD, with rivets and pins, but without cups or cup holders. (455) FOUR-BOTTLE HEAD, with rivets and pins, but without cups or cup holders. (456) . . . CUP HOLDER AND BRASS CUP. (457-457A) .60 .72 .18 .06 .03 .24 .30 .06 .06 .12 .03 .90 .42 .03 .10 .90 .36 9266. MOISTURE TESTER, Ames, for moisture in butter, consisting of a jacketed paraffine con- tainer made of copper. The outside shell has a rounded bottom to expose as much surface as possible to the heat from an alcohol lamp. An aluminum sample cup fits closely within the inside shell, having contact all the way down so that the heat from the paraffine is trans- mitted without loss. Complete with nickel-plated support stand, special thermometer reading from 100 to 200"C., alcohol lamp, tongs for lifting the sample out, and full directions. . 6.00 PAPER, Fat Free, for the determination of fat in milk, according to Adams' method. In boxes of 50 strips, 560x65 mm per box 2.80 362 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 9288. No. 9282. 9270. PASTEURIZING OUTFIT, for steam or hot water, consisting of a neatly finished vessel with convenient handles and cover, and with rack for holding eight sterilizing bottles. Beads around the sterilizing chamber mark the points to which water should be filled. Complete with bottles and brush for cleaning $4.50 9272. PIOSCOPE, or Milk Tester, Heeren's. For showing the richness of milk by color comparison. A set of appropriately labeled standard colors is furnished, together with a convenient means of comparing with the standards the color assumed by the sample of milk during the test. . . .75 9276. PIPETTES, Cream. No A B Capacity, cc 9 18 Each 15 .15 Per dozen 1.50 1.50 9278. PIPETTES, Milk. No A B Capacity, cc 8.8 17.6 Each 15 .15 Per dozen 1.50 1.50 9280. PIPETTES, Milk, 17.6 cc, in accordance with the specifications formulated by the Bureau of Standards and adopted by the .Official Dairy Instructors' Association and bv the State of Indiana Each .35 Per dozen 3.50 9282. PIPETTES, Milk, 17.6 cc, in accordance with the specifications formulated by the Dairy and Food Commission of Wisconsin Each .35 Per dozen 3.50 9284. PIPETTES, Milk and Cream, 17.6-18 cc combined Each .19 PIPETTES, Volumetric, see general heading Pipettes. Per dozen 1.90 9288. RACK, for Babcock Test Bottles, of tin. Hangs flat against the wall; the bottles stand upright and are easily filled. Capacity, 24 bottles 1.80 9292. RENNET TESTER, Marschall, a simple, reliable and indispensable aid to every cheese maker. It enables the maker to ascertain the condition of the milk, and to regulate its ripening to an exact point, alike every day, which is very essential in order to insure uniform work and uniform quality of the cheese. Includes graduated cup (a), a 1 cc pipette (b), a bottle (c) in which to dilute the rennet, and a spatula (d) for stirring the milk. Complete in a hand- some case 4.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 363 No. 9298. No. 9308. o Nos. 9322-5. No. 9314. A 9299. 9302. 9304. 0308. 9298. SALT TESTER FOR BUTTER, Nafis. This apparatus is automatic, easy to manipulate, and self-adjusting, and is especially suited for rapid determination of the per cent, of salts in butter. The liquid in the graduated tube instantly readjusts itself to zero so that the only reading to be taken in using the apparatus is at the point on the graduated scale where the liquid surface is located after the test is completed. With a 10-gram sample of butter each cc of solution drawn from the burette will equal % per cent, salt in the butter. Complete as illustrated together with 10-gram weight, 250 cc flask, standard solution in dry form, 25 cc pipette, porcelain cup, stirring rod, medicine dropper, beaker, 2-ounce bottle of indicator, and full directions $6.50 STIRRING ROD, Nans' Faultless, for use in No. 9298 Salt Tester. This rod is colored to show the exact tint taken by the sample when the test is complete 15 SCORE CARDS, Dairy Cattle, in tablets of 50 sheets Per tablet .20 SCORE CARDS, Market Cream, in tablets of 50 sheets Per tablet .20 SEDIMENT TESTER for Milk, as described by Professors Babcock and Farrington. Consists of a cylinder 2% inches in diameter and 6 inches long, funnel shaped at the bottom and ter- minating in an opening about 1 inch in diameter. In the cap at the bottom is a wire gauze strainer on which a thin disk of absorbent cotton is placed. After a pint sample of milk has been filtered through the apparatus, the cotton filter, with the dirt which it has collected, is detached and allowed to dry. The amount of dirt obtained will differ with different lots of milk and disks when dry may be returned to the milk producer as evidence as to the clean- liness of the milk. The central cylinder is surrounded by a steam or hot water jacket with % inch intervening space so that the milk can be kept hot and the filtering process thereby hastened. Complete with 500 disks and with bracket for mounting against the wall. 12.00 9309. DISKS, Absorbent Cotton, for use with No. 9308 Sediment Tester, in boxes of 100, per box .50 9314. SLIDE SCALE, Richmond's, for calculating the total solids in milk, with scale for tempera- ture correction of specific gravity. This slide rule will be found of great advantage and serv- ice to cheese factory men and milk inspectors, as well as those interested in the preparation and examination of milk for use of children and invalids 5.50 9316. TABLETS, Corrosive Sublimate, for keeping milk samples sweet. Used in making composite tests. Will color samples so that danger of mistakes is avoided. Small size will keep samples sweet for two weeks. In boxes of 50 tablets Per box .30 9317. TABLETS, Corrosive Sublimate, same as No. 9316, but large size, will keep samples sweet for four weeks. In boxes of 50 tablets Per box .50 9322. TESTER, Nafis, for Babcock Test Bottles, made of brass. To make a test, fill the bottle with alcohol deeply colored with black aniline or writing ink until it is almost opaque (this does away with the meniscus) so that the highest point is exactly even with the zero mark. Then slowly lower the Tester into the bottle until the liquid rises half way between the two sec- tions. At that point should be the middle mark. After that point is tested for, slowly lower the entire tester into the bottle so that the liquid rises over the top of the upper section about an eighth of an inch. If the liquid is even with the top mark and was also at the middle mark, the bottle is correct. For 6 inch, 10% milk test bottles 1.00 9323. TESTERS, Nafis, same as No. 9322, but for 6-inch 18-gram cream test bottles. No A B C For bottles, per cent 30 40 50 Each 1.25 1.50 1.65 9324. TESTER, Nafis, same as No. 9322, but for 6-inch, 9-gram, 50% cream test bottles 1.65 304 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. 1 No. 9330. No. 9332. 9325. No. 9334. No. 9338. No. 9342. TESTERS, Nafis, same as No. 9322, but for 9-inch cream test bottles. No A B For bottles, per cent 30 50 Each $1.65 1.65 TEST TUBES, Butter Fat Oil, plain, 9x% inches ; Per dozen TEST TUBES, Butter Fat Oil, with line 5 inches from bottom Per dozen TEST TUBES, Cream, heavy, for samples, 5x1*4 inches ... . .Fei dozen THERMOMETER, Dairy, standard, for those who wish a more accurate thermometer than the ordinary. Hand-written paper scale, one degree graduation, accurate within one division of the scale, weighted with shot and guaranteed to float upright. Ten inches long. Approximate scale range 10° to 110° Fahrenheit 2.40 9340. THERMOMETER, Pasteurizing, with enclosed hand-written paper scale; approximate scale range 30° to 220° Fahrenheit; graduated in 2° divisions and accurate within one division of the scale. 2.20 9330. 9332. 9334. 9338. C 55 1.65 .90 .90 .90 MILLS, see Crushing and Grinding Apparatus. 9342. MINERAL COLLECTION, in wooden cases with covers, each specimen with a label giving the name and locality. 100 specimens 5x6 cm.. LIST OF MINERALS INCLUDED. 26. Quartz, Chalcedony. 51. Aragonite. 27. Quartz, Agate. 52. Witherite. being in a pasteboard tray 35.00 1. Graphite. 2. Sulphur. 3. Copper. 4. Orpiment. a. Stibnite. 6. Molybdenite. 7. Galena. 8. Chalcocite. 9. Sphalerite. 10. Cinnabar. 11. Millerite. 12. Niccolite. 13. Pyrrhotite. 14. Bornite. 15. Chalcopyrite. 16. Pyrite. 17. Cobaltite. 18. Arsenopyrite. 19. Halite. 20. Fluorite. 21. Cryolite. 22. Quartz, Rock Crystal. 23. Quartz, Amethyst. 24. Quartz, Rose. 25. Quartz, Smoky. 28. Quartz, Flint. 29. Quartz, Jasper. 30. Opal, Semi-opal. 31. Cuprite. 32. Corundum. 33. Corundum-Emery. 34. Hematite crystal. 35. Hematite compact. 36. llmenite. 37. Magnetite. 38. Chromite. 39. Braunite. 40. Cassiterite. 41. Rutile. 42. Pyrolusite. 43. Limonite. 44. Bauxite. 45. Calcite crystal. 46. Calcite, Cleavage. 47. Caleite-Marble. 48. Magnesite. 49. Siderite. 50. Siderite-Clay Iron-Stone. 53. Strontianite. 54. Cerussite. 55. Malachite. 56. Orthoclase xld. 57. Orthoclase-cleavage. 58. Orthoclase-Sanidine. 59. Oligoclase. 60. Labradorite. 61. Enstatite. 62. Pyroxene. 63. Wollastonite. 64. Amphibole, Actinolite. 65. Amphibole, Hornblende. 66. Garnet. 67. Crysolite. Olivine. 68. Vesuvianite. 69. Zircon. 70. Andalusite. 71. Cyanite. 72. Epidote. 73. Calamine. 74. Tourmaline. 75. Chabazite. 76. Natrolite. 77. Muscovite. 78i Lepidolite. 79. Prochlorite. 80. Serpentine. 81. Talc, foliated. 82. Talc soapstone. 83. Sepiolite, Meerschaum. 84. Kaolinite. 85. Titanite. 86. Apatite. 87. Apatite. Phosphorite. 88. Lazulite. 89. Wavellite. 90. Barite. 91. Anglosite on Galena. 92. Gypsum. 93. Gypsum, Alabaster. 94. Alunite. 95. Wolframite. 96. Ozocerite. 97. Amber. 98. Asphaltum. 99. Anthracite. 100. Cannel Coal. 9343. MINERAL COLLECTION, same as No. 9342, but 100 specimens 3x4 cm 23.00 9344. MINERAL COLLECTION, same as No. 9343, but in pasteboard box instead of wooden case 18.00 MINERALS FOR WIRELESS TELEGRAPHY. Per ounce. Bornite, pure 20 Carborundum, crystals .15 Chalcopyrites, with Iron Pyrites ... .10 Chalcopyrites, pure .15 Franklinite .10 Galena, cubical 10 Iron Pyrites, crystallized, radiated. .10 Iron Pyrites, crystallized, cubical.. .15 Molybdenite Silicon, fused Stibnite, crystallized Zincite, 70 per cent Zincite, 100 per cent Rose's Metal, M. P. 203° F. . Wood's Metal, M. P. 158° F. Per ounce. 20 20 20 40 65 30 .30 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 365 No. 9346. No. 9347. 9346. MINERAL COLLECTION. An exceedingly fine collection of 110 specimens in a substantial hardwood box 23xl5i£x5 inches, with hinged cover. The specimens are in pasteboard trays, fitting in two wood trays, and are from one to three inches in linear dimensions, each one be- ing labeled. Contains every important mineral, including ores of Aluminum, Gold, Molybdenum, Tin, Antimony, Iron, Nickel, Titanium, Arsenic, Lead, Radium, Tungsten, Bismuth, Lithium, Silver, Uranium, Cobalt, Manganese, Strontium, Vanadium, Copper, Mercury, Tantalum, Zinc, and a large number of miscellaneous minerals $40.00 9347. MINERAL COLLECTION (Washington School Collection). Contains the following minerals and rocks, good size, each labeled and placed in a separate tray. The whole in a neat cloth covered case with a set of unlabeled duplicates (Set No. 9348) for student 4-50 1. Graphite. 2. Galena. 3. Sphalerite. 4. Chalcopyrites. 5. Pyrites. 6. Fluorite. 7. Quartz Crystal. 1. Conglomerate. 2. Friable Sandstone. 3. Red Sandstone. 4. Potter's Clay. 5. Shale. 6. Calcareous Tufa. 7. Oolitic Limestone. MINERALS. 8. Quartz, Milky. 9. Hematite. 10. Magnetite. 11. Limonite. 12. Calcite. 13. Siderite. 14. Orthoclase. ROCKS. 8. Fossiliferous Limestone. 9. Compact Limestone. 10. Peat. 11. Lignite. 12. Basalt. 13. Granite. 14. Diabase. 15. Amphibole (Hornblende). 16. Amphibole (Asbestos). 17. Garnet. 18. Muscovite. 19. Talc. 20. Gypsum. 15. Gneiss. 16. Mica Schist. 17. Quartzite. 18. Clay Slate. 19. Dolomite. 20. Residual Sand. 9348. STUDENT'S COLLECTION, consisting of smaller duplicate nnlabeled specimens of Set No. 9347 for student classification -45 9349. TRAYS, Mineralogical Specimen, made of heavy cardboard, covered on outside with black cloth. Inside black. Depth of each tray, % inch. Xo A B C D Size, outside, in inches 2x3 3x4 4x6 6x8 Each 10 .10 .15 .20 Per 100 . 6.00 7.00 10.00 15.00 366 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 9350. No. 9370. No. 9372. No. F7115. No. 9360. No. 9362. No. 9384. No. 9386. 9350. MITRE BOX, Olmstead's. Can be used with ordinary hand saw, which will do perfect work and not cut the frame away. Provided with iron guides for saw. Small size, will cut 1%-inch moulding, etc $1.95 MITTENS, see Gloves. 0360. MODELS, Atomic, Kekule and Von Baeyer, consisting of 20 black balls with four connecting posts each, 10 red balls with two connecting posts each, 30 white, 10 yellow, 10 green, 10 violet, and 10 silver colored balls each with tubular attachments to slip on the connecting posts, and 15 nickel-plated binding posts with two clamps 45.00 9362. MODELS, Valence, Nead's. The blocks representing the positive elements are provided with pins which fit into corresponding holes in the blocks which represent the negative elements or radi- cals. On each block is a clip for holding a card on which is printed the symbol of the element represented. With these blocks valence, the idea of bonds between the atoms in combination, and equation writing are made perfectly clear. The set includes 12 blocks for univalent elements, 6 for bivalent, and 4 for trivalent, half of each being positive, and 100 printed cards for symbols of elements and radicals 5.00 MOIST CHAMBERS, see Culture Dishes. MOISTURE TESTERS, see Grain Testing Apparatus. MOLD, Briquette, see Asphalt Testing Apparatus; Cement Testing Apparatus. MOLDS, Cement, see Cement Testing Apparatus. MOLDS, Cupel, see Cupel Molds. 9368. MOLD, Pouring, of cast iron with wood handle, with 3 conical depressions 2x1% inches each, tapering to a fine point, for crucible and scorification assays 75 9370. MOLD, Pouring, of heavy solid iron, with six conical machine drilled depressions, 21/4xl% inches each, with iron handle, for crucible and scorification assays 2.50 9372. MOLD, Pouring, of cast iron, with wood handle and two smooth drilled cavities 1.50 9374. MOLDS, Pouring, cast iron, with wood handle and round holes, for crucible and scorification assays. Number of cavities 6 12 Each 75 2.25 MOLECULAR WEIGHT DETERMINATION APPARATUS, see Physical Chemistry Appa- ratus. F711.">. MONOCHROMATIC FLAME ATTACHMENT for Bunsen burners. A small reservoir which slips over the top of the burner is provided with an asbestos wick at the center. This wick surrounds the mouth of the burner closely and feeds up to the flame any solution placed in tho reservoir. The flame is therefore continuously colored with the characteristic color of the salt which is in the solution, and frequent renewals are not necessary, as only a small portion of the dissolved substance is consumed. As the water evaporates more is easily supplied. For any burner with %0-ineh tube > 1.50 9384. MORTAR, Diamond, Leed's Form, of hardest steel. Pestle 50x15 mm 3.50 9386. MORTARS, Diamond, Plattner's, of hardest steel. No A B Diameter of pestle, mm 15 25 Each 4.50 6.00 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 367 No. 9390. No. 9394. No. 9396. No. 9388. 9388. MORTARS, Glass, with pestle. No Capacity, ounces Diameter outside, inches. . Each No. 9402. 9390. MORTARS, Iron, vase shape, heavy, with pestle. No ' A B Capacity, pints 1 2 Size, inches 4V>xa 5V>x6 Each . 1.20 1.60 A 2 2% $0.26 B 4 4 .40 C 4 2.25 C 8 4% .50 I) gallons 1 8x7 3.50 D 16 5 .80 E 32 6 1.20 E 2 6.40 9394. MORTARS, Iron, Buck's, for grinding and amalgamating. By rotation of the muller, a large sample of quartz may be ground in contact with mercury. No ". A B Diameter outside, inches 6% 8% Total weight, pounds 30 76 Weight of muller, pounds 16 49 Each 10.00 12.50 9396. MORTARS, Porcelain, with spout and pestle ; glazed outside, rough inside. Outside diameter, mm 65 80 100 110 130 150 16o 185 213 Eacli 35 .50 .60 .70 .95 1.25 1.35 1.55 2.20 9402. MORTARS, Wedgewood, acid proof, pestle with wood handle. No 0000 000 00 0 1 2 3 4 5 6 Diameter outside, inches 3 3% 4 4V, 5 5% 6% 7% 8 9 Each 68 .76 .86 .92* 1.00 1.20 1.40 1.60 1.90 2.30 MORTAR, Automatic Grinding, see Crushing and Grinding Apparatus. MOTORS, Electric, see Electrical Instruments. MOTOR-GENERATORS, see Electrical Instruments. MOUSE JARS, see Animal Holders. MUFFLE FURNACES, see Furnaces. MUFFLES for Gas and Oil Heated Furnaces, see Furnaces, Muffle. MUFFLES, Alundum, see note under Muffles, Opaque Fused Silica. MUFFLES, Clay, all kinds and sizes, send for special bulletin giving sizes and prices. MUFFLES, Opaque Fused Silica, see note below. Note:— Owing to the great variety of sizes and shapes of muffles in use throughout the coun- try, we have made no attempt to offer a complete list in this catalog. We shall be very glad to quote prices upon request upon muffles made of alundum, clay or silica. As it is very important that the muffle shall fit the space for which it is ordered, we urge that orders or requests for prices be accompanied by (1) a list of dimensions both outside and inside, (2) a statement as to whether both ends are open or one closed, and (3) a sketch showing the exact shape of the cross section of the old muffle. MUSEUM JARS, see Jars. 368 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 9408. No. 9450. No. 9410. MOTORS, WATER 9108. MOTOR, WATEE, 5 inches in diameter; may also be used witn* steam or compressed air. Has a two-speed steel pulley for %2'*n- round belt- Attains the following speeds, depending on the water pressure. Water pressure, Ibs 20 30 40 50 60 No. of r. p. in 2300 2800 3400 3850 4200 This motor may be attached to an ordinary apparatus stand and used for either stirring or shak- ing. The inlet pipe is threaded 1A in. I. P. thread $7.50 9410. MOTOE, CENCO WATEE, a reliable motor made by one of the largest manufacturers of water motors and fully guaranteed. This motor will be found useful for power in grinding, buffing, etc., and as a test of efficiency in the laboratory, also in connection with bottle washing brushes, for the rapid cleaning of bottles, flasks, etc. Diameter 4 inches, weight 5 pounds. With 80 pounds water pressure will develop % h. p. when connected with y2-inck house pipe. Com- plete with 4-inch beveled face emery wheel, one felt buffing wheel for brass and silver, one cake of brass and silver polish, one grooved wood pulley for ifa-inch round belt (see No. F2857), and coupling for threaded faucet 5.00 9412. MOTOE, CENCO WATEE. Same design as No. 9410. Diameter, 6 inches; weight, 7 pounds. With 80 pounds water pressure will develop % h. p. when connected with %-inch house pipe. Complete with grooved wheel for %2-in42. CORKS, specially selected for use in distilling flasks, sizes No. 6, 7, and 8 assorted, in bags of 100 '. per bag 1.25 9643. FIBER BOARD, with hole to fit over end of condenser tube and prevent escape of gas from receiving cylinder .10 FLASKS. "Distilling, Engler, see general heading Flasks. GRADUATES, Cylindrical, see general heading Cylinders. 9644. GUARD, for burner, of galvanized iron lined with asbestos 7.50 13622. THERMOMETER for Distillation of Gasoline, graduated to read from 0° to 270°C. Made according to specifications of the United States Bureau of Mines. Thermometers of other ranges or with Fahrenheit scale can be furnished shortly after receipt of order, if desired. (See Technical Paper 166, May 1917, page 21) 4.15 13624. THERMOMETER. Solid Stem, Engraved Scale, same as No. 13622, but graduated from 20" to 520°F.. in 2° divisions 4.15 9645. ASBESTOS MAT, 5 inches square, with circular opening 114 inches in diameter, for shielding sides of flask from direct flame 10 FLASH POINT TESTERS 9650. FLASH POINT TESTER, Cleveland Open Cup, for high grade lubricating oils, made of heavy brass castings. Complete with standard solid stem thermometer, graduated from 20 to 720°F[, with spirit lamp and Bunsen burner for gas 13.20 9'i.")2. FLASH POINT TESTER, Cleveland Open Cup, similar to Xo. 9650, but smaller and of lighter construction. Complete with solid stem thermometer and Bunsen burner 8.80 13636F. THERMOMETER only for Xos. 9650 and 9652, graduated from 20" to 720°F., in 2° divi- sions 4.95 9654. FLASH POINT TESTER, Elliott's, for illuminating oils only. Adopted as standard by the states of Xew York, Xew Jersey, Iowa and Michigan. Complete with glass cover, standard solid stem thermometer graduated to 300°F., lamp, thermometer holder, and directions for use 13.20 9655. PERFORATED GLASS COVERS for Xo. 9654 each .50 13636B. THERMOMETER for Xo. 9654, graduated from 20° to 300"F., in 1° divisions 2.65 965S. FLASH POINT TESTER, Foster's, for illuminating oils only. Complete with standard solid stem thermometer graduated to 190°F., alcohol lamp, and directions for use 14.30 9659. THERMOMETER for Xo. 9658, graduated from 60° to 190"F.. in 1° divisions, with metal scale 2.00 376 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 9662. No. 9668. No. 9676. 9662. 9663. 9664. 9668. 9669. 9670. 9676. 9677. 9678. 13608, FLASH POINT TESTER, Abel-Pensky, United States Bureau of Mines Modification, for oils flashing from 0° to 110°C., with clock work to open cup and apply flame. Complete with three thermometers, stirring device, cup lifter, burner and aneroid barometer, in portable case with instructions for operation. (See Technical Paper No. 49 of the United States Bureau of Mines) $148.50 THERMOMETERS for No. 9662, for use in oil cup. With round bulb, graduated in %° divi- sions. No .- A B Range, degrees C 0-50 40-110 Each 8.25 8.25 THERMOMETER for No. 9662, for use in water bath, with cylindrical bulb, graduated from 0° to 85°C. in 1° divisions " 8.25 FLASH POINT TESTER, Pensky-Martin, United States Bureau of Mines Modification, for oils flashing from 100° to 310°C. Consists of an oil cup with cover, fitted with stirrer, clockwork mechanism as in No. 9662 for opening cup and applying flame, and an air bath. Complete with two thermometers, cup lifter and burner, in portable case with instructions for operation. (See Technical Paper No. 49 of the United States Bureau of Mines) 132.00 THERMOMETERS for No. 9668, for use in oil cup, with round bulb, graduated in 1° divisions. No A B C Range, degrees C 100-210 200-310 300-410 Each 8.25 8.25 9.90 OIL CUP only for Nos. 91)1)2 and 90(58 8.25 FLASH POINT TESTER, Open Form, for illuminating oils. Complete with alcohol lamp, and standard paper scale thermometer 6.60 GAS FLAME TESTING BURNER for use with No. 9676 for dip or bar tost. With stop-cock to control size of flame and hose for attachment to gas supply 2.00 GLASS CUPS only for No. 9676 ". each .35 per dozen 3.30 THERMOMETER for No. 9676, graduated f :om — 20 to 230°F. in 1° divisions 3.30 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 377 No. 9686. No. 9706. No. 9694. FLASKS, Distilling. Engler, see general heading Flasks. FLASKS, Distilling, Hempel, see general heading Flasks. 9686 FREEZER, TagliaTrae Oil, for determining the congealing point of oils. Consists of an oil-cool- ing chamber, containing a receiver mounted on a rocking shaft to facilitate the introduction of the oil cup and to show whether congealing is taking place; and an ice chamber with dram faucet, surrounded by a heavy insulating jacket. A glass door enables the operator to observe the operation at all times. Two stop-cocks are connected with the oil-cooling chamber to enable air to be blown through to control the temperature. Complete as described with three special standard angle thermometers • • ; f52-80 Note: — This instrument is furnished to order only and we can not promise immediate ( GAGE RODS, FOR DETERMINING CAPACITY OF BARRELS 9692. GAGE ROD, of seasoned maple, 36 inches long 9694. GAGE ROD, of seasoned lancewood. 36 inches long, with steel point, ivory face, brass back and indicating slide, graduated to 120 gallons 5.77 9696. GAGE ROD, similar to No. 9694, but made to fold to 18 inches 6.16 9698. GAGE ROD, of solid tool steel, with hardwood handle, ivory face, and indicating slide, graduated to 120 gallons 9.90 HYDROMETERS, for Oil Testing, see general heading Hydrometers. 9706. LUBRICATION TESTER, Thurston's, for testing the lubricating quality of oils by means of the friction of a bearing on a rotating shaft. A heavy pendulum measures by its deviation the friction. The machine automatically records the pressure per square inch, the total pressure on the iournal, the total friction and the temperature of the bearing. F. O. B. . .Philadelphia 350.00 Note: — This instrument is furnished to order only and we cannot promise immediate delivery. 9710. MANUAL for Inspectors of Petroleum, containing correction tables for hydrometers, enabling the true gravity at any temperature to be deter- mined at a glance -20 9714. MELTING POINT TESTER, Tagliabue's for Wax. Requires only a tea- spoonful of material and enables a test to be made in ^ of the usual time. Complete with two standard thermometers 26.40 Note: — This instrument is furnished to order only and we cannot promise No. 9714. immediate delivery. 378 CENTKAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 9716. No. 9724. No. 9730. 9716. MELTING POINT TESTER, for Wax, consisting of a glass cup for the wax to be tested, with a removable metal top in which is set a thermometer graduated from 90° to 150°F., in %° divisions. The melted wax is poured into the cup until it stands at an indicated level. The cap with thermometer is then put in place and the instrument shaken until the wax shows signs of congealing. The thermometer is then observed and the temperature at which the mercury remains constant while the process of congealing continues is noted as the melting point. By means of this instrument the melting point of a wax may be measured within Vi°F. Complete as described with nickeled trimmings and with thermometer $10.00 9720. OIL TABLES, Tycos, containing all the data concerning gravities, temperatures, conversion tables, etc., which are of interest to the oil man 1.00 9724. OIL TUBE, Muter's, for determining fatty acids in oils and fats. Graduated from 0 to 100 cc in 1 cc divisions, with ground stopper and stop-cock, on wooden support. (See Journal of Association of Official Agricultural Chemists, Vol. II, No. 3, for November 15, 1916, page 309) 5.50 SAMPLE BOTTLES, for Oil, see general heading Bottles. SEPABATOEY FUNNELS, see general heading Funnels. 9730. STILL, Brown Oil, for fractionations and general distillations, constructed to meet the most exacting requirements. Th6 still is made of east iron surrounded by a cast iron frame, mounted inside of a fire-brick furnace of the same general shape. The flame from the Bun- sen burners plays between the frame surrounding the still and the fire-brick furnace. The still proper is heated only by heat which passes through the walls of the iron frame sur- rounding it. By this construction the top and bottom of the still may be kept at the same temperature; or, if desired, the top can be kept heated to a higher temperature, or vice versa, by a slight adjustment of the flame entering the fire chamber. It is necessary when running an emulsified oil to keep the top of the still somewhat hotter than the bottom. The still permits the use of a sample sufficient in size to afford cuts that can be treated or otherwise examined; and it fractionates where fractionation is desired. Two large Bunsen burners are included; one for heating the still, and one for generating steam. Capacity of still, one gallon (half full). Complete as described with four vapor lines and discharge pipes, condenser with four compartments, discharge outlet, steam generator and super-heater, Bunsen burners, three thermometer openings and large opening for cleaning purposes, with directions for uee '. 135.00 For other STILLS for Oil, see general heading Distilling Apparatus. STOP WATCHES, see general heading Stop Watches. CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. 379 No. 9738. No. 9742. No. 9748. B738. 974?. 974 pound boxes Per box $1.00 10454. PIPES, Clay Per dozen .25 PIPETTES PIPETTE, Automatic Dropping, with rubber bulb, for delivering exactly 1 cc. Convenient for filling ampoules 1.00 PIPETTES, Automatic Overflow, with patent three-way stop-cock, and reservoir for collecting the excess. Capacity, cc 10 25 50 Each 3.50 3.60 3.75 PIPETTE, Automatic Overflow, same as No. 10460, but with capacity of 17.6 ec for Milk Testing 3.50 PIPETTE, Calibrating, Ostwald's, capacity 2 cc 80 PIPETTE, Capillary, for preparing milk smears on microscope slides for counting the bacteria present. Graduated at i^oo cc. With a 6.4X ocular and a 1.9 mm objective (oil immersion), a 195 mm tube furnishes an apparent field of %ooo square cm. (See Bulletins 373 and 378 of the New York Experiment Station) 1.00 PIPETTES, Double Automatic, with stop-cock so made that one pipette fills while the other empties. Capacity, cc 25 50 100 Each 7.00 7.50 8.00 PIPETTE, Double Automatic, Rothe's, for use in determining iron as perchloride by means of ether. Graduated to 200 cc as illustrated 12.00 PIPETTES, Dropping, Medicine Droppers, with rubber bulb. Length, 4 inches; capacity, about .30 1320. 10460. 10461. 10464. 10466. 10470. 10472. 10476. 10477. 10480. 2 ee Per dozen PIPETTES, Dropping, same as No. 10476, but with tip curved Per dozen PIPETTES, Dropping, straight, without bulb. .30 Length, inches 8 12 Each .10 .15 10481. PIPETTES, Dropping, same as No. 10480, but with rubber bulb of 25 cc capacity. Length, inches 8 12 Each 30 .45 (Other lengths will be made to order.) PIPETTES, Gas, see Gas Analysis Apparatus. 10486. PIPETTE, Glucose, Spencer's, capacity 50 cc, graduated from 5° to 20° on the Brix scale in. 2.00 CENTBAL SCIENTIFIC CO., CHICAGO, U. B. A. 405 No. 10490. No. 10492. No. No. 10496. 10498. No. 10502. No. No. 10506. 10510. No. 10514. No. 10516. No. 10520. No. 10524. 10490. PIPETTE, Mercury, for taking up drops without danger of drawing them into the mouth $0.35 10492. PIPETTE, Mercury, for handling small drops of mercury 35 10496. PIPETTES, Mohr's, accurately graduated in ec and fractions. No A B C D E F G H J K Capacity, ce- }{0 1 1 2 5 10 20 25 50 100 Graduated to, cc.. Hoo Moo Mo Mo Mo Mo Mo Mo Mo Mo Each 40 .45 .40 .35 .40 .45 .55 .60 1.00 1.10 * 10498. PIPETTES, Mohr's, same as No. 10496, but with glass stop-cock. Capacity, cc 25 50 Graduated to, cc ' Mo Mo Each 1.70 1.90 10502. PIPETTES, Ostwald, as used in the determination of nitrogen, urea and ammonia in urine by the Folin method. Capacity, cc 1 2 Each 1.00 1.00 10506. PIPETTES, Serological, similar to No. 10496, but graduated to the extreme tip. No A B C D E Capacity, ce }io 1 1 5 10 Graduated to, cc ^ioo }{oo Mo Mo Mo Each 30 .40 .30 .30 .35 10510. PIPETTE. Sucrose, capacity 52.096 cc, graduated from 5" to 25° on the Brix scale in Motus 2-50 PIPETTE, Viscosity, see Nos. 10420-2. 10514. PIPETTES, Volume or Transfer, with bulb approximately in middle of tube. Capacity, ec 1 2 3 5 10 12 15 20 25 30 50 75 100 200 Each ..' 10 .11 .12 .15 .17 .20 .24 .26 .28 .30 .35 .45 .50 .60 10516. PIPETTES, Volume or Transfer, without bulb, as used in bacteriological work and water anal- ysis. Capacity, cc 1 5 10 Each 10 .15 .25 10520. PIPETTE, Wassennann Safety, for bacteriological and serological work, designed to prevent any danger of infection in handling samples. Sliding the glass cap upward with tubulation closed by the finger fills the pipette. Delivery is controlled by the finger. Graduated from the tip to 1^0 cc in Mooths 80 10524. PIPETTES, Water Analysis, as used in the Hygienic Laboratory of the United States Public Health Service. Set consists of three pipettes; one 11 cc pipette graduated at 0, 10 and 11 ce; one 10 ec pipette graduated from 0 to 10 cc in single cc; and one 2 cc pipette graduated from 0 to 1 cc in Mflths and with mark at 2 ee. Capacity, cc 2 10 11 Each 30 .30 .35 PIPETTES, Weighing, see Bottles, Weighing. 406 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 10544. No. 10548. No. 10556. No. 10560. No. 10574. PIPETTES, PRECISION OR NORMAL 10.130. PIPETTES, Mohr's, Precision or Normal, graduated at 20°C., to meet the requirements of the United States Bureau of Standards. With unofficial factory certificate. No A B C D E F Capacity, cc •. 1 1 5 10 25 50 Graduated to, cc Moo Mo Mo Mo Mo Mo Each $1.35 1.20 1.75 1.80 2.50 3.35 9 10531. PIPETTES, Mohr's, Precision or Normal, same as No. 10530 but standardized by the United States Bureau of Standards. With control stamp. No A B C D E V Capacity, cc 1 1 5 10 25 50 Graduated to, cc i,ioo Mo Mo Mo Mo Mo Each •. 3.70 3.40 3.80 4.50 5.60 6.00 10536. PIPETTES, Volumetric, Precision or Normal, graduated at 20°C., to meet the requirements of the United States Bureau of Standards. With unofficial factory certificate. Capacity, ee 1 2 5 10 25 50 100 Each 60 .70 .75 .90 1.05 1.20 1.65 10537. PIPETTES, Volumetric, Precision or Normal, same as No. 10536, but standardized by the United States Bureau of Standards. With control stamp. Capacity, cc 1 2 5 10 25 50 100 Each 1.90 1.90 2.00 2.10 2.25 2.60 3.40 10544. PIPETTE BOTTLE, with pipette ground into neck and cap ground on. For use with volatile and poisonous liquids. Capacity, cc 10 25 50 100 Each 2.50 3.00 3.50 4.00 For other PIPETTES, see Blood Testing Apparatus. 10548. PIPETTE BOX, cylindrical, for use in sterilizing pipettes, of sheet copper, with tightly fitting cover with handle. Length, 15 inches; diameter, 2 inches 1.80 10549. PIPETTE BOX, cylindrical, same as No. 10548, but made of sheet iron 1.30 10552. PIPETTE BOX, rectangular form, of sheet copper, with overhanging cover with handle. Size, 2x2x12% inches 3.30 10553. PIPETTE BOX, same as No. 10552, but made of sheet iron 1.75 10556. PIPETTE REST, of porcelain 60 10560. PIPETTE SUPPORTS, of hardwood, revolving, for 12 pipettes 2.70 PITCHERS, Acid, see Acid Pitchers. 10570. PLANE, Block, iron, 5% inches long, 1*4 -inch cutter 80 10572. PLANE, Double End, iron, 8 inches long, 1*4 -inch cutter. This plane may be used as a block plane, or by reversing the cutter and wedge it can be used to plane close up into corners or other difficult places 1.80 10574. PLANE, Jack, wood bench plane, 2-ineh cutter, double iron 1.40 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 407 No. 10606 (shown in horizontal position) . No. 10686. No. 10690. No. 10692. No. 10696. No 10606 (snown No. 10590. PLANT PHYSIOLOGY APPARATUS vertical^osition). (This section has been practically eliminated on account of the difficulty in obtaining deliveries. A return to normal conditions will result in a large section being inserted in the catalog covering the re- quirements for this subject.) 10590. AUXANOMETER, a : imple and practical apparatus for measuring plant growth. A silk thread attached to the plant passes over a pulley with which it is held in close contact by a weight. This pulley moves freely and the pointer attached to it is provided with a counterbalance. The scale is accurately divided, each division representing a growth of .01 inch, and may be placed at any desired height on the support rod $4.50 10606. CLINOSTAT, for investigations involving plants of moderate weight where great precision olf revolution is not required. It consists essentially of the works of a powerful eight-day clock, geared to a revolution in fifteen minutes and enclosed in a practically dust and moisture-proof case, 16 cm in diameter. A ball-bearing shaft takes the strain from the works, which are started and stopped by a cylindrical nut projecting from the upper surface. It is to be wound, not too tightly, once in two days, which may be accomplished without disturbing the plant. Properly used" it will carry a 4-inch or smaller pot horizontally, or a larger size vertically. As with all clinostats, however, it revolves with greater evenness the smaller the weight it has to carry, and consequently the smallest pots allowed by the subject under study should be used. The size with which the instrument works best is the three-inch, this size, how- ever, being larger than commonly supposed, since the measurements of pots are all internal. Complete as described with directions for use 25.00 PLATE, Arsenic, see Arsenic Plate. PLATES, Asbestos, see Asbestos Pads. PLATES, Desiccator, see Desiccators. 10686. PLATES. Glass, circular, for covering beakers, dishes, etc. Edges not ground. Diameter, mm 60 80 Each 06 .08 10688. PLATES, Glass, circular, same as Xo. 10686, but ground on one side. Diameter, mm 60 80 Each 10 .12 10690. PLATES, Glass, circular, snme as No. 10686, but with hole in center for stirring rod. roughly ground. Diameter, mm 75 Each 20 10692. PLATES, Glass, circular, same as No. 10690, but with hole at side for stirring rod. 100 120 .12 .U Edges not ground. 100 120 .16 .20 Diameter, mm Each 10696. PLATES, Glass, square, for covering jars, beakers, etc. Length of side, mm 50 Each 03 Per dozen 25 60 80 100 120 .15 .20 .25 .30 Edges not ground. 75 100 150 200 .04 .05 .10 .16 .40 .50 .95 1.60 150 .16 150 .24 Edges 100 .25 150 .40 250 .25 2.50 10698. PLATES, Glass, square, same as No. 10696, but of double thick glass and ground on one side. Edges not ground. No A B C D E P Length of side, mm 50 75 100 150 200 250 Each 04 .05 .06 .09 .20 .30 Per dozen 40 .50 .60 .90 2.00 3.00 10702. PLATES, Glass, heavy plate, square, ground rough on one side, with edges slightly ground. For use with bell jars, etc. Length of side, mm... 100 125 150 200 250 300 375 500 Each 30 .40 .50 .70 1.20 1.50 2.25 3.75 10708. PLATES, Glass, blue cobalt, rectangular, for flame tests. Size, mm 50x50 50x75 75x75 75x100 100x100 Each 10 .12 .15 .20 .25 408 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 10756. No. 10760. No. 10720. No. 10750. No. 10746. fF7151. PLATES, Glass, colored, of best pot glass, 10 cm square. Colors as near spectral as possible to produce. Edges not ground. B indigo .15 C blue .15 D green .15 E yellow .15 No A Color violet Each $0.15 PLATES, Hot, see Hot Plates. PLATES, Porcelain Filter, see Filter Disks No. 5366.. 10720. PLATE, Porcelain, for color reactions. Size 90x110 mm, with 12 concavities 10724. PLATE, Porcelain, glazed, round, 5% inches in diameter 10726. PLATE, Porcelain, glazed, square, 5V2x5% inches PLATE, Porcelain Streak, see Arsenic Plate. 7316. PLATE, Porous Clay, dinner plates, for quickly drying precipitates and crystals. 8 inches F orange .15 G red .15 .70 .75 .75 Diameter, .25 PLATINUM WARE Our platinum ware is warranted pure and of the most approved shapes. Dishes and crucibles are all hammered and thoroughly tested after being finished. We carry in stock only those forms for which there is the greatest demand. All others furnished shortly after receipt of order. Special shapes and designs will be made to order. Platinum ware will be sent only by registered U. S. mail. We advise that scrap platinum sent in for credit or exchange be shipped in the same manner. Old or scrap platinum is bought at the market price. Weights given below are approximate only. Prices will be governed by the Market Price of Platinum. 1455. BLOWPIPE TIP, Platinum, for Plattner 's blowpipe. 10740. BOATS, Platinum, for combustion. Width, V2 inch; depth, % inch; with handles. Length, inches 1% 2 3% Approximate weight, grams 3 4 6 6.5 10742. BOAT, Platinum Filter, and Holder, Blair's, for iron and steel analysis. Length, about 2 inches; width, about % inch; depth, about %e inch. Approximate weight of boat and holder com- plete, 19 grams. 10743. HOLDER for Blair's Platinum Boat No. 10742, of rubber • 2.50 10746. COMBUSTION TUBE, Platinum, Seamless, 12x% inch, with prolongation 5x% inch; approxi- mate weight, 130 grams. Other sizes to order. 10750. CONES, Platinum Filter, seamless, 60°, profusely perforated with holes .016 to .025 inch. Diameter, inches % 1 1% 1% 2 Approximate weight, grams - 1 2.1 3.1 5.3 9.2 10752. CONE Of Wood, with wooden mold, for reshaping platinum filter cones to the correct angle 7.00 10756. PLATINUM CRUCIBLES, with cover. Crucible and cover weigh approximately as many grams as they hold cubic centimeters. Covers are always furnished unless specified otherwise. Capacity, cc 8 10 15 20 25 30 Diameter and depth, mm 22 25 30 33 35 40 Approximate weight, grams 8 10 15 20 25 30 Prices will be governed by the market price of platinum. 10760. CRUCIBLES, Platinum, Gooch'S, with perforated bottom, with cover and cap for bottom. Capacity, cc 10 15 20 25 Diameter and depth, mm 27 32 33 36 Approximate weight, grams 13 18 22 29 30 39 34 10762. CRUCIBLE, Platinum, Gooch'S, low form with large filtering surface, as used in bitumen and asphalt analysis. Capacity, 30 cc; approximate weight, 30 grams. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 409 No. 10764. No. 10768 No. 10794. No. 10798. No. 10800. 10764. CBUCIBLE, Platinum, J. Lawrence Smith's, with cover, for alkali determinations in rocks and minerals. Height, 80 mm; diameter at top, 18 mm; at bottom, 15 mm; capacity, 18 ec; approximate weight with cover, 34 grams. (See Bulletin Xo. 422, United States Geological Survey, page 172.) 10768. CRUCIBLE, Platinum, Shimer's Combustion, for determining carbon in iron and steel. Capacity, cc 30 Approximate weight, grams 52 (Special booklet will be sent on application.) 10772. DISHES, Platinum, evaporating, round bottom, with lip. Capacity, ce 15 20 25 35 50 Diameter, mm 38 42 44 48 56 Approximate weight, grams. .5 6 8 12 17 10774. DISHES, Platinum, Blair's, for iron analysis, rimmed. Capacity, ec 60 93 /o 65 100 125 150 200 250 72 78 84 94 98 33 42 50 67 80 Flat bottom, wfth straight sides and lip, wire 280 380 525 300 104 94 Approximate weight, grams 80 100 120 10778. DISH, Platinum, Classen's, for electrolytic analysis, with either polished or sand-blasted inner surface. Diameter, 90 mm; depth, 42 mm; capacity, 250 ec; approximate weight, 35 grams. (In ordering kindly specify kind of inner surface desired.) 10780. DISHES, Platinum, Incinerating, rectangular shape with flat bottom. Capacity, ce 15- 20 Approximate weight, grams 10 14 10782. DISH, Platinum, Milk Analysis, capacity, 45 ec; approximate weight, 17 grams. 10784. DISH, Platinum, Payne's, for fertilizer analysis, flat bottom with lip, wire rimmed, Capacity, 100 cc; approximate weight. 40 grams. 10788. DISH, Platinum, Sugar Analysis, lipped, with flat bottom and straight sides. Capacity, 35 cc; approximate weight, 16 -grams. 10790. DISH, Platinum, Sugar Analysis, deep form with handle. Capacity, 28 cc; approximate weight, 15 grams. 10792. DISHES, Platinum, Sugar Analysis, flat bottom, with or without lip or handle. Capacity, ec 10 20 25 35 Approximate weight, grams 10 14 18 20 (In ordering specify whether lip and handle are desired.) 10794. DISH, Platinum, Sugar or Milk Analysis, with two handles and lip. Made only to order. Capac- ity, 45 cc: approximate weight, 15 grams. 10798. DISH, Platinum, Water Analysis, round bottom, shallow form, without lip. Capacity, 100 ce. Approximate weight. 20 grams. 10800. DISH, Platinum, Water or Iron and Steel Analysis, shallow form with lip. Capacity, 45 ce; approximate weight, 15 grams. 410 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 10806A. No. 10806B. No. 10806C. No. 10808A. No. 10808B. No. 10808C. No. 10810. No. 10828. No. 10812B. No. 10812C. No. 10814. No. 10822. No. 10834. 1080C. ELECTRODES, Platinum Anodes, for electro-analytical work, made of heavy wire. No .' A B C Length, mm 150 150 125 Diameter of spiral, mm 38 50 15 Approximate weight, grams 8-9 20 7 10808. ELECTRODES, Platinum Cathodes, for electro-analytical work, made of platinum sheet. No A B C Diameter, mm 57 25 25 Length of electrode, mm 75 50 50 Approximate weight, grams 20 11 11 10810. ELECTRODE, Platinum Gauze Cathode, Hollard's, with special wire frame anode, designed to prevent formation of bubbles. Approximate weight, 37 grams. Diameter of anode, 2 inches. 10812. ELECTRODES, Platinum Gauze, cylindrical form, of 52-mesh gauze. Diameter, 25 mm; height of cylinder, 50 mm. No A B C Form open closed rotating Approximate weight, grams 7 6 18 10814. ELECTRODE, Platinum, Classen's Plate, with rod. Diameter, 1 inch; length of stem, 4 inches. In ordering, kindly specify thickness of plate desired. 10818. FOIL, Platinum. Style light medium Thickness, inches .001 Approximate grams per square inch 0.353 (Other thicknesses from tissue to plates can be supplied upon short notice.) FORCEPS, with Platinum Tips, see Forceps. 10822. GATJZE, Platinum. Mesh Size of wires, B. & S. gage. .002 0.705 45 31 Approximate grams per square inch 1.500 MUFFLES, Platinum, any size or shape made to order. 10828. SPATULAS, Platinum. No Length, inches Approximate weight, grams 10830. SPONGE, Platinum, Wired, for hydrogen ignition. 10834. SPOONS, Platinum, for deflagration in blowpipe analysis. No A Diameter of bowl, inches % Depth of bowl, inches %2 Approximate weight, grams 0.9 TONGS with Platinum Tips, see Tongs, Crucible. 2.0 4.2 A 2% 5 D 4.6 heavy .004 1.411 52 38 0.543 B 4 8 E 6.5 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 411 No. 10872. No. 10870. 10838. TRIANGLES, Platinum, with flat, solid ends. For crucible, cc ; 10 15 20 30 40 Length of side, inches 1% 1% 1% 2% 2% Size of wire, inches 045 .045 .055 .055 .064 Approximate weight, grams 5 8 11 12 15 10842. TRIANGLES, Platinum, for use in Holder No. 13950, made of heavy wire. For crucible, cc 10 "l5 20 30 40 Size of wire, inches 047 .047 .050 .050 .062 Approximate weight, grams 2.0 2.5 4.5 5.0 7.5 TRIANGLE HOLDER for No. 10842, see No. 13950. WEIGHTS. Platinum, see general heading Balances and Weights. 10816. PLATINUM WIRE. B. & 8. gage 18 20 22 23 24 25 26 27 28 29 30 32 34 36 Grams per foot.. 5.37 3.41 2.08 1.76 1.33 1.08 0.85 0.65 0.56 0.41 0.33 0.21 0.14 0.09 HOLDER for Platinum Wire, see No. 7990. 10856. FLIERS, flat nose. Length, inches 5 6 Each $0-70 .80 10858. PLIERS, round nose. Length, inches 5 6 Each 25 .40 10862. PLIERS, Combination. Gas plier, wire cutter, wrench and screw driver combined. Drop forged from high grade tool steel and warranted free from defects. Nickel-plated. A very useful tool. Length, inches 6 10 Each .50 .90 10864. PLIERS, Combination. A flat nose gas plier and wire cutter combined. Open throat, parallel jaws, full nickel-plated. Length, 5% inches 1.75 10866. loses. 10870. 10872. PLIERS, Gas, cast steel, fine quality. Length, 9 inches. PLIERS, Nippers, Diagonal Cutting, convenient for cutting in places difficult of access. Length, inches 5 Each 1.50 PLIERS, Nippers, End Cutting, 6-inch. .70 6 2.00 •60 PLIERS, Nippers, End Cutting, Bernard's, 6-inch, open throat jaws, nickel-plated, interchange- able parts. Its compound system of leverage makes this tool a very powerful cutter. . 3.00 412 CENTBAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 10894. No. 10884. No. 10886. 10874. 10876. 10878. 10884. 10886. Open throat, parallel jaws, nickel-plated. 6 1.70 2.25 6 .90 .15 10892. 10894. 10895. 10896. 10897. 10898. FLIERS, Wire Cutting. Flat nose, side cutting pliers. Length, inches Each $1.30 PLIERS, Wire Cutting, Bernard's. Length, inches Each PLIERS, Wire Cutting, Button's patent. Length, inches 4% Each 70 PLUMB BOB, Iron, japanned, weight, 9 ounces PLUMB BOB, Mercury. Made from solid steel rod, bored out and filled with mercury, which makes it unusually heavy in proportion' to its size, and the center of gravity low. The small diameter allows it to be used close to corners and walls. The point is hardened and the body and point ground. Nickel-plated and furnished with a braided silk line. Size, 4x% inches; weight, 2% ounces 1.00 PNEUMATIC TROUGHS, see Troughs, Pneumatic. For Polariscopes and Accessories, write for special information. POLICEMEN, see Rubber Policemen. POLISHING HEAD. Japanned iron frame; steel spindle % of an inch in diameter and 8 inches long; adjustable boxes. Carefully threaded taper screw on one end and three-jawed chuck for 0 to %o-inch drills on the other. Fitted to hold emery wheels, circular saws, buffers, etc., which have %-inch hole and are not over %-inch in thickness. Height, 7 inches. Pulley -will take %2-inch round or %-inch flat belt. Net weight, 2-% Ibs 2.50 POLISHING HEAD. Japanned iron frame; steel spindle %-inch in diameter and 10 inches long; adjustable boxes. Carefully threaded taper screw on one end and three-jawed chuck for 0 to J/4-inch drills on the other. Fitted to hold emery wheels, circular saws, buffers, etc., which have %-inch hole and are not over %-inch in thickness. Height, 7 inches. Pulley will take %2-inch round or %-inch flat belt. Net weight, 4*4 Ibs 4.00 ACCESSORIES FOR NOS. 10892-4 POLISHING HEADS. CIRCULAR SAWS, good quality steel, 2% inches in diameter. No A Size hole, inches. . .\ % For Polishing Head No 10892 Each 40 EMERY WHEELS, fine quality, 3 inches in diameter, %-inch thick. No. A Size hole, inches. . % For Polishing Head No 10892 Each 70 FELT POLISHING WHEEL, fine quality felt, 5 inches in diameter, 1-inch wide, %-inch hole. Fits screw end of either No. 10892 or No. 10894 Polishing Head 4.10 MUSLIN BUFF WHEELS. 35 pieces heavy muslin, strongly attached together; 3 inches in diameter. No A Size hole, inches % For Polishing Head No 10892 Each . 30 B % 10894 .55 B % 10894 .70 B 108~94 .30 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 413 No. 10924. No. 10926. No. 10928. No. 10932. 10902. 10904. 10905. 10906. 10910, 10911, 10914. 10916. 10918. 3131. 10922. 10924. 10926. 10928. 10932, POLISHING HEADS, Electric, for either A. C. or D. C. Will meet all requirements for light grinding, buffing, etc. Motor enclosed, protecting all working parts from flying dust and dirt. Bearings are made of extra heavy phosphor bronze, steel shaft *£-inch in diameter. Lubrica- tion is automatic by means of feed wick oil cups. Motor practically noiseless in operation. Has a speed of 3,000 r. p. m. and will develop i/6 h. p. Dimensions: height over all, 9Ms inches; base, 6x5 inches; length of shaft, 9VS inches. Finished in black japan. Buffing attachment to hold small buffs for buffing wheel may be had. (See No. 10905.) Has emery wheel 5 inches in diameter, %-inch face, indicating snap switch, attachment plug and six feet reinforced cord. No A B C D A. C. D. C. For volts 110 220 110 220 POLISHING HEADS, with adjustable tool rest $48.00 48.00 36.00 36.00 POLISHING HEADS, without tool rest 43.50 43.50 31.50 31.50 BUFFING ATTACHMENT, for either of the above Electric Polishing Heads 2.50 PULLEY, 2^ inches in diameter, for %0-ineh round belt, for attaching to shaft of Nos. 10902 and 10904 1.00 ^OBCELAIN WARE, see specific headings, Capsules, Crucibles, Dishes, Mortars, etc. POTASH BULBS POTASH BULB. Bender & Holbein, with aluminum base 2.75 POTASH BULB, Bender & Holbein, glass parts only 2.50 POTASH BULBS, Bowen. No ." A B Size small large Each 2.50 3.00 POTASH BULB. Geissler 1.50 POTASH BULB, Geissler, with drying tube ground on 2.00 POTASH BULB. Johnson, as used in Combustion Apparatus No. 3120 1.00 POTASH BULB. Liebig, with five bulbs 50 POTASH BULB. Liebig-Dittmar, with trap 80 POTASH BULB, Mitscherlich 50 POTASH BULB, Norris, as used in determining sulphur in iron and steel •' .60 POTASH BULB, Peligot, with three bulbs 40 POTASH BULB, Vanier, see Absorption Tubes. 414 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 10936. No. 10938. No. 10962. No. 10984. No. 10986. No. 10990. No. F2217. 10936. POTASH BULB, Wetzel-Geissler, with drying tube attached by rubber tubing... $2.50 10938. POTASH BULBS, Winkler, spiral form. No A B Height, mm 100 180 Bach 2.00 2.50 10942. POTASH BULB, Zahradink, with drying tube ground on. Convenient to use as it stands easily on its own base 3.00 For other POTASH BULBS, see Absorption Bulbs and Tubes. POTASH BULB SUPPORTS, see Supports. 10946. POTATO CUTTER, Ravenel, for cutting potato cylinders 18 mm in diameter and halving them at the same time 2.00 PRECIPITATING JARS, see Jars. PRESS, Filter, see Filter Press. 2400. PRESS, Pellet, for use in calorimetric determinations for briquetting powdered fuels.... 20.00 10962. PRESSES, Tincture, extra heavy, for making tinctures, extracts, etc. Capacity, quarts 1 2 4 8 Each 2.00 2.50 4.00 6.00 PRISMS, see Catalog F of Physical Apparatus. PROJECTION APPARATUS, see Catalog F of Physical Apparatus. PROOFING CABINETS, see Flour Testing Apparatus. PSYCHROMETERS, see Hygrometers. F2217. PULSE or PALM GLASS, Franklin's. Two glass bulbs with connecting tube, containing water and water vapor. When one bulb is held in the hand, the warmth of the hand is sufficient to cause rapid evaporation of the water, thus causing sufficient pressure to force the liquid into the other bulb, where a rapid boiling occurs. About 18 em long .65 PUMPS, Acid, see Acid Pumps. PUMPS, Air, Blowers, see general heading Blowers. PUMPS, Air, Filter, see Filter Pumps. AIR PUMPS, COMPRESSION AND VACUUM 10980. PUMP, AIR, Compression. A so-called hand bicycle pump 13.5 cm long by 2 cm in diameter .50 10984. PUMP, AIR, Vacuum and Pressure. Cylinder is of heavy brass, nickel-plated, 40 cm long by 54 mm in diameter. A vacuum to 29]/^ in. may be obtained by use of this pump. Mounted on an oak base 15.00 10986. PUMP, AIR, Vacuum and Pressure. Useful in elementary work in the laboratory and where only a partial vacuum is desired. Cylinder is of brass, 28 cm long by 2.5 cm in diameter. Mounted on stirrup for ease in using 4.50 10987. EXTRA VALVE for No. 10986 Air Pump 05 For PUMP PLATES, see page 416. 10990. AIR TANK, for use especially with Nos. 10984 or 10986 Air Pumps. A 12 liter air tank with a 30 Ib. pressure gage mounted on a nicely finished hardwood base. For convenience in mov- ing from place to place the support is provided with a handle and an air drying tube is mounted on one of the uprights as shown in the illustration. This apparatus may be used where air un- (lor pressure is needed, e. g., for driving stirrers in chemical laboratories. With stopcock at both air inlet and air outlet and with rubber tube for connection with Nos. 10984 or 10986. . 20.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 415 PC- Vertical Section. No. 11000. Horizontal Section through Gears. No. 11002-3. PUMPS, CENCO-NELSON HIGH VACUUM. These pumps represent the most recent development in High Vacuum Pumps for laboratory and commercial purposes. They are compact, operate with very small expenditure of power, require no attention when in operation and should last indefinitely. They measure about seven inches high by five inches in diameter at the base and weigh approximately ten pounds. The pulley is grooved for >4-inch round belt. Cenco-Xelson Pumps consist essentially of rotating gears, in pairs, running in accurately fitting housings. The whole mechanism is immersed in a cistern of oil, which serves the double purpose of seal- ing all the joints air-tight, and of lubricating the moving parts. The pumps are made with either two or three pairs of gears and are known as the two-stage and three-stage pumps respectively. The Two-stage Pump contains two pairs of gears, arranged one above the other. The upper pair takes the air from the inlet tube and delivers it to the lower pair, which forces it out through the exhaust. The Three-stage Pump contains three pairs of gears arranged in the same way. The Three- stage Pump is capable of producing a higher vacuum than the Two-stage one. When operating for any length of time, these pumps will become warm. As this raises the vapor tension of the oil, it is objectionable when a high vacuum is desired. To offset this effect, a cooling system is provided on the Three-stage Pump by means of which the oil is kept cool by circulation of water. The most efficient speed of operation is between 800 and 900 r. p. m. At this speed the pumps give just as good results as when operated faster, and develop less heat. For driving these pumps, a constant speed type of motor is most satisfactory; if for D. C., a shunt wound motor, or if for A. C., an induction motor. If a series wound (variable speed) motor is used, the speed of the motor will decrease as the vacuum rises, and the operator has no control over the speed, unless a rheostat is used in connection with the motor. A motor of % horse power should be used for continuous duty. Under favorable conditions, a vacuum of 0.1 mm may be obtained with the Two-stage Pump. On continuous service, some heating takes place, which lowers the vacuum somewhat. With the Three- stage Pump, watei cooled, a vacuum of .05 mm may be obtained by using proper precautions. The displacement of these pumps in free air, according to tests in our laboratory, is approximately 285 cu. in. per minute, or 10 cu. ft. per hour, at a speed of 900 r. p. m. They will evacuate a flask of one liter capacity to a vacuum of 1 mm in two minutes. No A B Number of stages 2 3 Vacuum, mm 0.1 0.05 11000. PUMPS, CENCO-NELSON, unmounted $25.00 35.00 11001. PUMPS, CENCO-NELSON, on hardwood base, without motor 30.00 40.00 11002. PUMPS, CENCO-NELSON, on hardwood bast with % h. p., 110 volt A. C. Motor. 60.00 70.00 11003. PUMPS, CENCO-NELSON, on hardwood base with %h. p., 110 volt D.C. Motor. 60.00 70.00 416 CENTRAL SCIENTIFIC CO., CHICAGO, TT. 8. A. No. 11010. No. 10992. No. 10994. No. 11012. 10992. PUMP, AIR, Vacuum, Lever Action, with two valves; polished brass cylinder, 56 mm diameter, stroke 16.5 cm; air pump plate of glass, 25 cm in diameter, ground plane and resting in a cast iron mold, with guard plug and vent screw; base and pillar of polished hardwood, mahogany finish. Base 25x60 em $25.00 10994. PTJMP, ATE, Vacuum, Geryk Design. This oil sealed pump is manufactured by us and has all the excellencies of this well-known design. It has no valves in the usual sense of the word, the pistons working in oil, which follows and seals the inlets and outlets so that leakage is impos- sible. The present model is finely constructed of brass and cast iron, handsomely finished, and is provided with a pump plate of plate glass 25 cm in diameter, cemented in the base. The air opening in the center of the pump plate is fitted with a safety plug which prevents the en- trance of mercury and other undesirable substances, while permitting the free passage of air, and there is also another opening at the side of the base for attachment of pressure gages, etc. The piston is 48 mm in diameter with a 9 cm stroke and is operated by a hand wheel grooved for %6-in. round belt, as shown in the illustration. A vacuum of 0.15 mm may be obtained. 45.00 10995. COUNTERSHAFT, for use with No. 10994 Air Pump when it is desired to use electric motor drive. This countershaft is mounted on No. F197 Clamp and when used with a % horse power motor of 1800 r. p. m. with a 1^-inch pulley, will drive No. 10994 at about 55 r. p. m ... 7.50 AIR PUMP ACCESSORIES 11010. AIR PUMP PLATE, of iron, 20 cm in diameter, cast in one piece to minimize danger of leak- age. Ground plane and provided with brass stop cock. The vent hole at the center is tapped (%6~16) for air pump accessories and provided with guard plug (No. F1941) 5.00 11012. AIR PUMP PLATE, of heavy plate glass, 25 cm in diameter; ground plane and firmly cemented in a low form tripod base of iron. The base is cast in one piece to minimize danger of leak- age and provided with brass stopcock and brass connecting tube with oil-sealed taps for inlet of air and for manometer. Finest workmanship throughout. The vent hole at the center is tapped (%6"16) f°r a'r pump accessories and provided with a guard plug (No. F1941) . . 12.00 For PRESSURE TUBING, see general heading, Rubber Tubing. 11020, OIL, Pump. Especially adapted for lubricating air pump cylinders and for use in oil sealed pumps such as No. 10994 Per half -pint can .30 11022. OIL, Pump. Especially adapted for use in the Cenco-Nelson High Vacuum Pumps. In metal cans. No A B C 1) Size 1 pt. 1 qt. 1 gal. 5 gal. Per can 25 .35 1.25 5.00 11028. VACUUM WAX. The best preparation on the market for using on apparatus in connection with the Air Pump, especially where high vacua are desired. Will not injure the pump plate or ap- paratus. Will not harden and can therefore be easily removed. Superior to vaseline, tallow or heavy oil > Per 4 oz. jar .30 CENTRAL SCIENTIFIC CO., CHICAGO, U. a A. 417 No. 11040. No. 11044. No. 11048. No. 11054. 11032. PUMP, Little Giant Lift, and Force, for keeping the laboratory plumbing clean. Will clean and open any clogged waste pipe without removing connections. Works by vacuum and pressure, and will break up any solid waste or obstruction caused by chemical action in a few minutes. The pump is made of heavy brass with attachments of pure rubber. The cup is of steel, is non-collapsible and is of sufficient size to permit its use over 4-inch screen drains. An adjust- able washer is furnished for use where the other cup will not fit 86.00 11040. PUNCHES, hollow cast steel. Hole diameter, inches % % % % Each 15 .20 .30 .35 11042. PUNCH, spring, cast steel, double joint; for leather, etc. Length, 714 inches .50 11044. PUNCH, Paper, Samson, The most powerful hand punch made; will perforate anything from a thin sheet of steel to ^4-inch paper. Nickel-plated and fitted with $i6-ineh die 2.50 PURINOMETER, see Urine Analysis Apparatus. 11048. PYCNOMZTEB. Drushel, as used by the Bureau of Mines for measuring the specific gravity of small quantities of light petroleum distillates. (See Bulletin 125 of the United States Bureau of Mines) 1-00 For other PYCNOMETERS, see Specific Gravity Bottles. PYROMETERS 11054. PYROMETERS. Brown Expansion, operating through the difference in expansion of graphite rods and the steel stem enclosing them. A compensating device corrects for differences in the amount of stem immersed above 12 inches. The graduated dial is of porcelain, 6% inches in diameter, and is not affected by heat or gases. Furnished with a 36-inch stem which should be inserted in the heat up to 12 inches or more. No A B C Graduated to, degrees F 800 1200 1500 Each 16.50 22.00 27.50 Note: — Pyrometers No. 11054 can be furnished with dial graduated in corresponding Centigrade ranges "if desired without additional charge. They may also be obtained with dial set for horizontal use of stem. 11058. PYROMETERS, Brown High Resistance, Portable Type, for use with either base metal or plati- num thermo-couples. The scale is 5 inches long with mirror for accurate reading. A locking device is provided which automatically locks the pointer when the case is closed, preventing damage in handling or shipment. The instrument has a resistance of 600 ohms and its read- ings are independent of the length of lead wires. Complete with 15 feet double-conductor \vire. in polished hardwood case with hinged cover, without thermo-couple. No A B C D E F G H J Bange 0 to de°rees F. 800 1000 1200 1600 1800 2000 2400 2600 3000 Graduated to. deg. F. 5 10 10 10 20 20 20 20 25 Each 82.50 82.50 82.50 82.50 82.50 82.50 82.50 82.50 82.50 (For illustration of No. 11058, see next page.) CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. EiEGTfUC PYROMETER THE BROWN UlSTBUMEtfr Nos. 11058-64. Nos. 11072-4. Nos. 11068-70. 11060. PYROMETERS, Brown High Resistance, Portable Type, same as No. 11058, but with scale gradu- ated in Centigrade degrees. No .-. A B C D E F Range, 0 to degrees C 400 600 800 1000 1200 1600 Graduated to, degrees C 5 5 5 10 10 10 Each $82.50 82.50 82.50 82.50 82.50 82.50 11062. PYROMETERS, Brown Low Resistance, Portable Type, same as No. 11058, but with resistance of only 5 ohms, for use with base metal thermo-couples only. No A B C D E Range, 0 to degrees F 800 1000 1200 1600 1800 Graduated to, degrees F 5 10 10 10 20 Each 55.00 55.00 55.00 55.00 55.00 11064. PYROMETERS, Brown Low Resistance, Portable Type, sanu> as No. 11062, but with scale gradu- ated in Centigrade degrees. No A B C D Range, 0 to degrees C 400 600 800 1000 Graduated to, degrees C 5 5 5 10 Each 55.00 55.00 55.00 55.00 11068. PYROMETERS, Brown High Resistance, Permanent Type, for wall use, with high resistance, which renders its readings independent of the length or temperature of the connecting wires. For use with either base metal or platinum thermo-couples. Resistance with base metal thermo-couples, 600 to 1000 ohms. B CDEFGH J 1000 1200 1600 1800 2000 2400 2600 3000 10 10 10 20 20 20 20 25 82.50 82.50 82.50 82.50 82.50 82.50 82.50 82.50 No A Range, 0 to degrees F. 800 Graduated to, deg. F. 5 Each 82.50 11070. PYROMETERS. Brown High Resistance, Permanent Type, same as No. 11068, but with scale graduated in Centigrade degrees. No A B C D E F Range, 0 to degrees C 400 600 800 1000 1200 1600 Graduated to, degrees C 5 5 5 10 10 10 Each 82.50 82.50 82.50 82.50 82.50 82.50 11072. PYROMETERS, Brown Low Resistance, Permanent Type, for wall use, with resistance of 5 ohms, for use with base metal thermo-couples only. Length of scale, 6 inches. No A B C D E Range, 0 to degrees F 800 1000 1200 1600 1800 Graduated to, degrees F 5 10 10 10 20 Each 55.00 55.00 55.00 55.00 55.00 Note: — A smaller instrument with 4% inch scale can be supplied if desired at $5.00 less. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 419 Nos. 11086-7. 11074. PYROMETERS, Brown Low Resistance, Permanent Type, same as No. 11072, but with scale graduated in Centigrade degrees. No A B C D Bange, 0 to degrees C 400 600 800 1000 Graduated to, degrees C 5 5 5 10 Each $55.00 55.00 55.00 55.00 See note under 11072. 11075. PYROMETERS, Brown High Resistance. Recording Type, for use with either base metal or platinum thermo-couples. Complete with 8-day clock, 100 twenty-four hour parchment charts and 50 feet double-conductor wire, but without thermo-couple. No A B C D E P G Bange, 75 to, degrees F 800 1200 1600 2000 2400 3000 3600 Graduated to, degrees F 20 25 25 50 50 50 20 Each 137.50 137.50 137.50 137.50 137.50 137.50 137.50 11080. PYROMETERS, Brown High Resistance, Recording Type, same as No. 11078 but with scale graduated in degrees Centigrade. No \ B C D E F Bange, 25 to, degrees C 400 600 800 1000 1200 1600 Graduated to, degrees C 5 10 10 20 25 25 Each i 137.50 137.50 137.50 137.50 137.50 137.50 11086. PYROMETERS, Brown Recording, Continuous Type, for use where a continuous record of the temperature is desired over long periods of time. An 8-day clock mechanism operates the record roll, over which passes a two months' roll of carbon paper. A pointer strikes the car- bon band once a minute and produces the record. No ink is required. Complete with one roll of carbon and one of record paper, and with 50 feet of double conductor wire. Xo A B C D Bange, 75 to, degrees F 800 1200 2000 3000 Graduated to, degrees F 5 10 ?."> 50 Each 220.00 220.00 220.00 220.00 11087. PYROMETERS. Brown Recording, Continuous Type, same as No. 11086, but with chart gradu- ated in degrees C. No A B C Bange. 25 to, degrees C 800 1200 1600 Graduated to, degrees C 10 10 20 Each 220.00 220.00 220.00 11(188. EXTRA CHART ROLLS for Nos. 110S6-7 each 2.75 11089. EXTRA CARBON MARKING ROLLS for Nos. 11086-7 each .55 PYROMETER, Brown Precision Heatmeter, write for special information. PYROMETER, Brown Transformation Point, for determining the recalescence and decalescence points of steel, write for special bulletin. 11092. PROTECTING CASES, for Brown Pyrometers, Permanent Type, of polished hardwood with glass front, with brackets for fastening to wall. Price includes mounting of instruments in case before shipment, but not price of instruments. No A B For Pyrometer, tvpe high resistance low resistance Each ". ." 6.60 6.60 420 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 11100. No. 11102. 11093. PROTECTING CASES, similar to No. 11092, but intended to contain both Pyrometer and switchboard. The switch handle extends through the glass door, and is provided with a stuf- fing box to make the opening dustproof. As the contacts wear, the spring tension can be tight- ened up without opening the case. Price includes mounting of instruments and switchboard in case before shipment, but not price of instrument or switchboard. No A B For Pyrometer, type high resistance low resistance Each $8.25 8.25 Note: — Nos. 11092 and 11093 should be ordered when the Pyrometer is ordered, as it must be mounted at the factory. 11096. SWITCHBOARDS, for use with Brown Pyrometers where several thermo-couples are to be con- nected to the same Indicating or Recording Pyrometer. This is a rotary switch with posi- tive spring contacts, the tension of which may be taken up as the contacts wear. Number of points 2 4 6 8 12 16 Each 6.60 7.70 8.80 9.90 12.10 14.30 11100. THERMO-COUPLES, Base Metal, for use with Nos. 11058 to 11088, for measuring temperatures up to 1800°F., and for intermittent use up to 2000°F. The couple consists of two %-inch rods of nickel alloy welded together at one end and insulated throughout their lengths by asbestos for temperatures up to 1000°F., and by lava above that temperature. Complete with head and binding posts for attaching lead wires, and with protecting tube of steel pipe unless otherwise specified. With adjustable flange. Length, 24 inches 8.80 Note^ — For lengths above 24 inches per foot, add 1.10 11102. THERMO-COUPLES. Platinum, for use with Nos. 11058 to 11088, for temperatures up to 3000°F., or 1600°C. The couple consists of one wire of chemically pure platinum and one of an alloy of platinum with 10 per cent, rhodium, of a diameter of 0.02 inch. The wires are insulated by small fire-clay tubes pierced with two holes. Complete with iron head and porcelain block with binding posts, and with protecting sheath of porcelain. (If specified in ordering, a quartz sheath may be furnished instead of porcelain.) Length, inches 12 18 24 36 Each 38.50 50.60 60.50 79.20 11106. PROTECTING TUBES, Graphite, for Thermo-Couples, for protection from molten metals. Length, inches 12 18 24 36 Each 3.30 4.40 6.60 8.80 11108. PROTECTING TUBES, Nickel-Chromium, for base metal thermo-couples for use at tempera- tures between 1500° and 2000°F. They may also be used in lead hardening baths, and as an additional protection over porcelain or quartz tubes. Length, inches 12 18 24 Each 5.50 8.80 12.10 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 421 No. 11140. Nos. 11130-2. 39 7.15 They B 1*4 .83 11112. PROTECTING TUBES, Porcelain, for Platinum Thermo-Couples, with a melting point of 3600T. They should not be subjected to sudden changes of temperature. Length, inches 12 18 27 39 Each . $4.40 5.50 7.45 11.00 11118. PROTECTING TUBES. Quartz, for use where sudden fluctuations in temperature are met with, or where a tube with very small lag is desired. Melting point, about 2400T. Length, inches '. 12 18 27 Each 3.85 4.40 5.25 11120. PROTECTING TUBES, Steel, for Base Metal Thermo-Couples, to protect from gases, etc. should not be used at temperatures above 1400°F., nor in an oxidizing atmosphere. No A Diameter outside, inches % Per foot . ...... - 55 11122. PROTECTING TUBES, Calorized Steel, subjected to calorizing which increases the life of the steel when used at high temperatures. Length, inches 12 18 24 36 Each 2.75 3.30 3.85 4.95 11130. PYROMETERS, Hoskins Low Resistance, Portable Type, complete with 36-inch thermo-couple of Alumel and Chromel wires, twisted and welded together. The special feature of this out- fit is the fact that the operator can easily make his own thermo-couples, when replacement is necessary. The Alumel and Chromel wires can be obtained in coils of various gages, so cali- brated that all couples made from two given coils are interchangeable. The ends of the wires should be twisted together and welded, and are then ready for use. Complete with low- resistance portable indicator in black enameled aluminum ease 6*4x6x3 inches, weighing 5 pounds; 36-inch standard thermo-couple; and 20 feet of flexible leads. Xo A B Range. 32 to, degrees F 1000 1500 Graduated to, degrees F 10 20 Each 47.00 47.00 11132. PYROMETERS, Hoskins Low Resistance, Portable Type, same as No. 11130, but with scale graduated in Centigrade degrees. No A Bange, 0 to, degrees C 550 Graduated to, degrees C 5 Each 47.00 11140. PYROMETER, Scimatco Optical, Patented, for measurements of temperatures from 1200° to 7200°F. With this instrument, direct observation is made of the object whose temperature is to be measured. The instrument can be readily standardized by the operator in a few minutes time. There are no errors due to connecting wires, cold junctions, temperature changes, or sensitive electrical instruments. The life of the instrument with ordinary care is indefinite, and the only cost of upkeep is that of recharging the storage battery. Espe- cially suited for use in foundries, blast furnaces, steel works, glass factories, smelters, gas works, brick and tile factories, porcelain factories and in research work on high tempera- tures. Complete with tripod, storage battery, current regulator, 3 extra lamps and bottle of amyl acetate, in two carrying cases. Bange," 800° to 2000°C 175.00 B 800 10 47.00 C 2000 20 47.00 C 1100 10 47.00 D 2500 25 47.00 D 1400 20 47.00 41.-2 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 11154. Nos. 11162-5. 11142. PYROMETER, Scimatco Optical, same as No. 11140, but with scale graduated from 1400° to 3000°F $175.00 ITote: — Higher ranges can be supplied if desired. 11154. PYROMETERS, Shore's Pyroscope, for measurement of temperatures by comparison of the color of the heated object with that of a kerosene flame. This instrument was designed especially for the heat treatment of steel and for brass foundry work, but can be used for any measurements within the ranges given. The instrument is self contained and easily por- table, requiring no batteries or electrical connections of any kind. The entire operation con- sists in focusing the telescope upon the object whose temperature is to be measured, turning the knob which operates the diaphragm until the difference in color disappears and then reading the temperature from the graduated drum. Complete with instrument as described, and with small and large tripods for mounting at convenient height. No A B Range, degrees F 1200-2100 2000-3000 Each 65.00 65.00 11162. PYROMETERS, Thwing Radiation, Portable Type, for measurements of temperatures of objects in furnaces, of objects in motion, or in inaccessible places, by means of the heat radiated from the object. The instrument consists of a Receiving Tube for collecting the radiation and concentrating it upon a sensitive thermo-couple, and a Galvanometer to measure the cur- rent thus generated. The design of the tube makes it independent of the distance from the hot body, provided the surface is of sufficient area to fill the angle formed by the opening in the tube. The instrument is very rapid, requiring an interval of only 5 seconds before a reading may be made after the tube is pointed at the object. Convenient for use in cement kilns, open hearth furnaces, carborundum furnaces, electric furnaces, brick kilns, lime kilns, smelting furnaces, coke ovens, boiler fire pits, hardening furnaces, etc. It should not be used for gases, flames or transparent bodies, nor where there is much smoke or flame. Complete with tube 30 inches long divided in two sections, portable indicator in aluminum case with 4-inch scale with zero adjustment, and with connecting cord. No A B C D E F G Range, degrees F... 500-1400 800-1800 1000-2500 1400-2500 1200-2800 1000-3000 1400-3500 Each 135.00 135.00 135.00 135.00 135.00 135.00 135.00 11163. PYROMETERS, Thwing Radiation, Portable Type, same as No. 11162, but with double scale; graduated in Fahrenheit degrees. No , A B Range, degrees F 1000-2500 600-1650 500-1500 D 400-1200 E 600-1800 Each No. 1800-3600 1000-3000 1000-2500 800-2800 1200-3600 145.00 145.00 145.00 145.00 145.00 F G H Range, degrees F 1000-2500 600-1600 300-1000 800-2200 2000-4500 1200-2800 1000-3000 1500-3200 Each . 145.00 145.00 145.00 145.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 423 No. 11167. 11104. PYROMETERS, Thwing Radiation, Portable Type, same as No. 11162, but with scale graduated in Centigrade degrees. No A B C Range, degrees C 600-1500 Each $135.00 11105. PYROMETERS, Thwing Radiation, Portable Type, same as No. 11164, but with double scale; graduated in Centigrade degrees. ~ E F 600-1500 500-1700 1000-2500 1500-3000 500-1700 1000-2000 135.00 135.00 No. Range, degrees C... A 200-800 500-1700 145.00 B 500-1400 800-2000 145.00 C 1000-2000 1500-4000 145.00 D 500-1000 600-1500 145.00 G 500-1800 1200-3000 Each 145.00 145.00 145.00 145.00 145.00 145.00 145.00 11166. CARRYING CASE for Nos. 11162-11165, with leather handles 10.00 11167. PYROMETERS, Thwing Radiation, Portable Type, for laboratory use, in polished mahogany case, with 6-inch scale. Ranges for this instrument are the same as those given under Nos. 11162 to 11165. No A B Type single scale double scale Each 145.00 155.00 In ordering, kindly specify scale and range desired. See Nos. 11162 to 11165. 11168. PYROMETERS, Thwing Radiation, Permanent Type, same as No. 11162, but with wall type indicator and ventilated receiving tube for permanent installation. With either single or double scales, graduated in Fahrenheit or Centigrade degrees. Write for information as to ranges and prices. Note: — Thwing Radiation Pyrometers may be secured with other ranges than those listed, and with triple range scales if desired. We shall be glad to furnish information and prices upon request. Send for special bulletin containing full description. QUARTZ APPARATUS, Transparent, see general headings, Crucibles, Dishes, Flasks, etc. RACKS, All Bands, see Supports. RACKS, Milk Test Bottle, see Milk Testing Apparatus. RADIO-ACTIVITY APPARATUS F2758. ELECTROSCOPE, Box Form. Consists of a metal box about 10x10x10 cm with removable glass front and back. The brass rod carrying the strips of gold-foil is insulated by pure amber, giv- ing the best insulation possible. To obviate radio-active influences, a metal cap is provided to fit over the collar on top of the box and enclose the projecting rod. This electroscope -will re- tain its charge for from 6 to 8 days 4.00 ELECTROSCOPE, Lind Interchangeable, as used by the United States Bureau of Mines. This in- strument can be assembled to suit the needs of the operator from the parts described below. (See Bulletin 104, United States Bureau of Mines, Chapter V.) 11200. ELECTROSCOPE HEAD, consisting of a nickel-plated housing containing the leaf system and supporting the reading microscope. It is closed in the front and rear by sheet mica. A fine wire grating makes contact with the mica to ground stray charges. The leaf system is insu- lated by means of an amberoid plug, fitted into a threaded cap, by means of which the leaf may be readily removed. The aluminum leaf is charged by means of a rod set in hard rubber at the right-hand side. Opposite, on the left, is a protector for the leaf when in transporta- tion, which should be withdrawn to full distance when in use. At the bottom of the leaf sup- port is a light spring, to make electrical contact with the interchangeable discharge chambers. 424 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. 8. A. NO. 11208. ELECTROSCOPE HEAD, Continued. No. 11203 with No. 11200 mounted on it. 11201. 11202. 11203. 11204. 11205. 11206. 11207. 11208. 11209. 11210. 11211. The Microscope, magnification, 24-fold; focal distance 32 mm, is carried by a projecting soliil front, and is very firmly fixed with relation to the leaf. It may be refocused, however, by releasing a split collar controlled by a heavy milled-head screw. The microscope has a gradu- ated and numbered micrometer scale in the eye-piece by which the motion of the leaf is measured. The Head as a whole comprises a very compact readily transportable unit, and yet one that can be easily taken apart if it is desired to do so. Complete as described $63.00 OPEN DISCHARGE CHAMBER FOR SOLIDS, a cylinder for use with Head No. 11200, 10.5 cm high, 9 cm in diameter, with a door 5 cm high, and 9 cm broad. The plate electrode is 5.5 cm in diameter and is supported horizontally at 1.5 cm below the tep of the chamber, by a rod that passes up through an amberoid insulator, and terminates in a cap to fit the inter- changeable top. The chamber is provided with a friction cap to protect the insulator when not in use 15.00 GAS-TIGHT EMANATION CHAMBER, for use with Head No. 11200, 10.5 cm high, 9 cm in diameter, provided with two special gas-tight stop-cocks. Volume, about % liter. The am- beroid insulation is made gas-tight by a special mechanical joint without any wax or other binding material. Since each emanation chapiber can be used only once daily, as many dupli- cates must be provided as it is desired to make daily determinations, all being used with one top. At least one extra Charging Cap No. 11210 is needed with more than one chamber. 18.75 LIGHT WALLED WATER CHAMBER, height, 13 inches; diameter, 10 inches; weight, 4 pounds; capacity, about 4 gallons. Intended especially for field use with Head No. 11200, where water is introduced directly into the chambers. Amberoid insulation, stop-cock outlet above, and large opening below, with rubber stopper for introduction of water 15.00 HEAVY WALLED WATER CHAMBER, for use with Head No. 11200. Height, 13 inches; diameter, 10 inches; weight, 13 pounds; capacity, about 4 gallons. Intended for laboratory use, the walls being rigid enough to support a complete vacuum for the boiling-off method. Water can also be introduced directly if desired. Price quoted upon application. PLATE FOR SOLIDS, 5.5 cm in diameter with narrow rim 2 mm deep, to be used with No. 11201. At least two, and probably more, are desirable each 1.25 CHARGING ROD, a tapering rod of hard rubber 8 inches long, for charging in field work and where battery is not available -50 BATTERY SET, consisting of dry cells connected in series, in covered wooden box, with insu- lated wire to guard one end of battery, charging wire with floating terminal and knife switch to protect whole. Dimensions of box, 18x15x6 inches 43.00 GAS BURETTES FOR EMANATION, a glass burette with one capillary two-way stop-cock above and one wide-bore cock below. Length of burette, 60 cm; diameter, 3 cm; length over all, 80 cm. Two are desirable for rapid work each 10.00 MICRO-DRYING BULBS for Sulphuric Acid, to be used between Nos. 11202 and 11208 in transferring gases. One is needed for each gas burette •• 1-50 CHARGING CAP, of hard rubber with binding post, to be used in maintaining charge on No. 11202 when Head No. 11200 is in use 1.50 HAND PUMP, Vacuum or Pressure, of special construction for use in evacuating No. 11202 Chamber . 10.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 425 No. 11244. 11212. WRENCH for removing electrode collars from Chambers Xos. 11201 to 11204 $1.10 0036. ALUMINUM Foil, in books of 25 leaves, 5x5 inches per book .45 11214. WOODEN SUPPORT for No. 11200, when not on chamber 3.00 11215. WOODEN CASE for Field Sets Xos. 11224, 11230, 11232 and 11234 8.00 12962. STOP WATCH, 7 jewelled. 12.50 11217. ANALYZED LE DOUX PITCH BLEND (about 60% TJ3 08), with Radium data, to be used in calibrating Chambers No. 11202 directly in terms of radium emanation, by the solution and boiling method. Enough for 50 calibrations 4.00 11218. ANALYZED DE DOUX CARNOTITE (about 1.5% U3 08), to be used in No. 11205 Plates in Chamber Xo. 11201 for solid comparison per 25 grains 1.50 11219. ANALYZED LE DOUX CARNOTTTE (about 2% TT3 08) per 25 grams 2.00 11220. ANALYZED LE DOUX CARNOTITE (about 3f"c TT3 08) per 25 grams 3.00 RECOMMENDED SETS. 11224. COMPLETE FIELD OUTFIT for Ores, consisting of one each Xos. 11200, 11201, 11206, 11212, 6036, 11218, 11219, 11220, 11215, 12962, and two No. 11205 105.75 11226. COMPLETE LABORATORY OUTFIT for Solids, Gases (Emanation Method) and Liquids (Water), consisting of one each Xos. 11200, 11201, 11206, 11207, 11211, 11212, 6036, 11214, 11217, 11218, 11219, 11220, and two each Nos. 11202, 11205, 11208, 11209 and 11210 182.50 11228. SIMPLE LABORATORY OUTFIT for Solids, Gases and Liquids, without battery set, pump, water chamber, and stop watch, consisting of one each Xos. 11200, 11201, 11202, 11206, 11208, 11209, 11210, 11212, 6036, 11214, 11217 and 11219 126.75 11230. COMPLETE LABORATORY AND FIELD OUTFIT for Water Analysis, consisting of one each Xos. 11200, 11203, 11206, 11208, 11209, 11210, 11211, 11212, 6036, 11214, 11215, 11217 and 11219 i 120.00 11232. SIMPLE LABORATORY AND FIELD OUTFIT for Water Analysis, consisting of one each Xos. 11200, 11203, 11204, 11206, 11212, 6036, 11215 and 11217 110.00 11234. SIMPLE FIELD OUTFIT for Water Analysis, consisting of one each Nos. 11200, 11203, 11206, 11212, 6036, 11215, 12962 and 11217 100.00 11244. ELECTROSCOPE, land Gamma Ray, as used by the United States Bureau of Mines. This is a single unit outfit, not interchangeable, consisting of a nickel-plated brass cylinder 13 cm high and 9 cm in diameter, with lead lining inside 3 mm thick. The leaf system is in the discharge chamber itself, into which is also fixed, by means of a split collar with heavy screw, the reading microscope with numbered scale. The chamber is mounted on one end of a wooden base 33 x 6 inches, along which extends a nickel-plated track 27 inches long on which a light carriage sup- port for the radium tube may be fixed by a binding screw at any desired distance from the discharge chamber. The carriage supports the radium tube horizontally at a height just oppo- site the middle of the chamber. The radium tube is held by a light spring clip against a con- cave bar, graduated in l^e inch divisions, to facilitate centering the tube and determining its length. A removable lead screen 6 x 6 x ^4 inches is placed immediately against, the discharge chamber, to shield it from the radium tube. Complete as described. (See Bulletin 104, of the United States Bureau of Mines, Chapter V) 80.00 11246. ELECTROSCOPE, Gamma Ray Outfit, for the measurement of tubes of radium or of emanation, suitable for use by physicians and hospitals, consisting of Gamma Ray Electroscojft? No. 11244, Stop "Watch No. 12962 'and Charging Rod Xo. 11206 ". 95.00 MINERALS FOR RADIO-ACTIVITY 11250. CALC-SPAR, in pieces about 40 x 15 x 6 mm per piece .75 11251. CARNOTITE (Radium Ore). High grade specimens. Xo A B C Size Small. Medium. Large. Each .75 1.50 2.25 11252. FLUORSPAR CUBES, approximately 13 mm on a side per cube 1.50 11253. KUNZITE, fluorescent per 6 grams 1.50 11255. THORIUM NITRATE per ounce 1.10 426 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 11280. No. 11284. No. F2177. No. 11300. No. 11304. No. 11308. 11253. URANIUM NITRATE per ounce $0.60 11259. URANIUM OXIDE (yellow) per ounce .50 11261. WILLEMITE, Flourescent , per ounce .75 11262. WILLEMITE, Phosphorescent per ounce 1.50 11264. ZINC SULPHIDE, PHOSPHORESCENT, extra strong phosphorescence; produces very large scin- tillations with radium. In vials of 5 grams Per vial 2.00 11265. ZINC SULPHIDE, PHOSPHORESCENT, strong phosphorescence. In vials of 5 grams. Per vial 1.00 11266. ZINC SULPHIDE, TRIBOLUMINESCENT. Shows a markea luminosity when rubbed; is also phosphorescent. In vials of 5 grams Per vial 2.00 11268. FLUORESCENT SCREEN, 65 x 45 mm 1.60 11280. RADIOSCOPE, for detecting the presence o; radio-activity in waters, ores, etc., by viewing scintillations on a phosphorescent screen. These scintillations are produced by the alpha par- ticles emitted by the emanation evolved from radio-active substances. The instrument con- sists of a jar for holding the substance under test, provided with a screw cap fitted with an adjustable compound lens and a phosphorescent zinc sulphide screen. The emanation rises from the jar into the cap and there causes scintillations on the screen. With each Badioscope is supplied a quantity of high grade carnotite (radium) ore which may be used to learn the use of the instrument. Size 20x7.5 cm 10.00 11284. SPINTHARISCOPE, for showing the radiant energy of radium salt. Consists of a nickel-plated metal tube, 19x35 mm, with a phosphorescent screen at one end and a high grade lens at the other. Projecting from the center of the phosphorescent screen is a pin on the side of which has been placed a small quantity of radium salt. With this instrument the scintillations pro- duced on the phosphorescent screen by the constantly emanating alpha particles are shown in the most marvelous manner. In order to observe this phenomenon in the day time the observer should remain in a darkened room for a short time, so that the eye may become sufficiently sensitive 4.00 F2177. RADIOMETER, Crookes', illustrating phenomena of radiant heat. Mounted on glass base. . RAW MATERIALS, see list at end of letter W. RAZORS, Section, see Microtome Accessories. READING GLASSES, see Magnifiers. READING TELESCOPES, sec Catalog F of Physical Apparatus. REAGENT BOTTLES, see Bottles. RECALESCENCE OUTFIT, see Furnaces, Electric; Pyrometers; or write for special informa- tion. 11300. RECEIVERS, Retort, glass, plain. Capacity, ee 125 250 500 Each 50 .55 .65 11304. RECEIVERS, Retort, glass, with tubulature and glass stopper. Capacity, cc 125 250 500 Each . 75 .85 1.00 11308. RECEIVER, Pauly's, for distillation in vacuum. RECEIVERS for Blowers, see Blowers. RECTIFIERS, see Electrical Instruments. With adapter and four bulbs 1000 .75 1000 1.25 3.00 CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. 427 J No. 11320. No. 11472. 11314. 11316. 11320. : --1. 11450. 1 !452. REDUCTOR, Blair's, for the determination of phosphorus in "steel, by the zinc filtration method. With glass stop-cock. (See Blair 's Analysis of Iron. 8th Edition, page 89) .. $2.00 REDUCTOR. Blair's, same as Xo. 11314, but complete with support, elamp, two flasks, glass stop-cock, and connecting tubes 6.00 REDUCTION TUBE, of Pyrex hard glass, with bulb on end. Length, 15 em $0.25 REDUCTION TUBES, of Pyrex hard glass, with bulbs in center. Xo '. A Number of bulbs 1 Length, mm 300 Each .30 For EEFEACTOMETERS and ACCESSORIES, write for special information. REGULATORS. Gas and Electrical, see Thenno-regnlatoTS. REGULATORS. Gas Pressure, see Xos. 6530, 6556 and 7070. RESERVOIRS. Leveling, see Bulbs, Leveling, Xo. 1902. RESPIRATOR, for protection from dust, sawdust, smoke, fumes and gases. -Made of soft rub- ber and provided with a perfect filter device; easily kept clean and bends perfectly to fit the B 2 350 .42 C 3 400 .50 face 1.75 1146-2. 11468. 11472. 11478. RESPIRATOR or Face Mask, of felted material so formed as to make an air-tight joint around the face, thereby protecting the eyes, nose and lungs from dust, smoke, fumes and gases. The filters, upon which the efficacy of the mask depends, do not need renewing and are guar- anteed for three years. For the eyes there is a large celluloid or mica covered opening, per- mitting perfect vision to all points 10.00 RETORT ADAPTERS, see Adapters. RETORT RECEIVERS, see Receivers. RETORTS. Copper, for making oxygen; flask shape, with iron elamp and brass delivery tube fitted with ground joint. Capacity, ec 250 500 _ Each 2.90 3.40 4.15 5.60 RETORTS. Copper for distillation, see Distilling Apparatus. RETORTS. Glass, plain. Capacity, cc 125 250 500 1000 Each .70 .80 .90 1.00 RETORTS. Glass, tabulated, with ground glass stopper. Capacity, ec 125 250 500 ' Each LOO LIO L25 1.80 RETORTS, Iron, for distilling mercury, ete.; with removable cover, fastened by screw elamp, with delivery tube ground in the cover. Capaeity.ee 250 500 ; 4 Each 3.80 4.10 4-50 6.00 8.00 428 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 11502. No. 11504. No. 11536. No. 11530. RETORT, Iron, Skidmores, see No. 3440. 11484. RETORTS, Transparent Quartz, plain. Capacity, cc 50 100 200 Each $15.00 20.65 38.40 REVOLUTION COUNTERS, see Speed Counters. RHEOSTATS, see Electrical Instruments. 11492. RINGS, Concentric, Copper, tinned inside, for water baths, with cover. Number of rings in set 5 6 Outside diameter of largest ring, inches 3% 4% 5% 6% Per set 30 .40 .50 .60 11494. RINGS, Concentric, Iron, with two removable rings, with heavy screw for clamping on support for supporting water baths, sand baths, flasks, etc. Diameter of outside ring, 6 inches . . .40 11498. RINGS, Concentric, Porcelain, with cover. Number of rings in set 5 6 Outside diameter of largest ring, cm 16 20.5 Per set 1.65 2.20 11502. RINGS, Iron, for attaching to retort stands; with %6 inch screw. Distance from rod to center of rings, 4% inches. Outside diameter, inches 2 567 Inside diameter, inches l^io %%6 3% 4^s 5% 6 Each 20 .21 .22 .25 .26 .35 11504. RINGS, Iron, Extension, for fastening to retort stand by means of Clamp Holders Nos. 2914 and 2916. Length of rod, 7% inches. Outside diameter, inches 34567 Each 12 .15 .18 .20 .25 RINGS, Suberite, see Cork Rings No. 3296. RING STANDS, see Supports. ROASTING DISHES, see Dishes, Roasting, No. 3864. 11512. ROPE, Manila, good quality, %-inch diameter. (No order taken for less than 12 ft.) .Per foot .04 RUBBER GOODS RUBBER BAGS, see Gas Bags No. 6720. 11520. RUBBER BANDS, assorted, in *4 pound boxes Per box 1.00 RUBBER BOTTLES, see Bottles. 11524. RUBBER BULBS, for dropping pipettes, etc. Capacity, cc 5 Each . .' 04 .05 11526. RUBBER BULBS, large size, heavy walled, for pipettes, etc. Capacity, ce 25 50 Length, inches 3% Diameter, inches 1 Vi 2 Each 15 .20 11530. RUBBER BULB, with hard rubber valves, for pressure only, with connecting tube. Capacity, about 50 cc 30 RUBBER BULB EXPANDER, see No. 11630. 6645. RUBBER BULB, of pure gum, with flexible tube for use with gas analysis apparatus. . .60 6832. RUBBER BULB, with double valves of hard rubber for use in sampling gas for analysis .60 RUBBER BULBS, double, for pressure, see Blower No. 1382. 11536. RUBBER CAPS, flat shape, for test tubes of same diameter as caps. Diameter, inches - % % % Per dozen 1.00 1.05 1.10 1.20 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. 429 No. 11552. No. 11556. No. 11562. No. 11572. 11540. RUBBER CEMENT, for cementing rubber joints, rubber, etc ............ Per ounce bottle $0.15 11544. RUBBER DAM, pure gum ........................................... Per square foot SO 11546. RUBBER DAM, pure gum, 36 inches wide ............................. Per linear foot 1.00 RUBBER DISKS for Foot Bellows, see Blowers. RUBBER FINGER COTS, see Finger Cots, Rubber No. 5514. RUBBER FUNNELS, see Funnels. RUBBER GLOVES, see Gloves. 11552. RUBBER POLICEMEN, narrow shape, for removing precipitates from walls of beakers, etc.; flat end, %x%6 inch. Complete with glass rod 6x%6 inches ................... Each .09 Per dozen .90 11553. RUBBER POLICEMEN. Same as No. 11552, but without glass rod ........... Per dozen .45 11556. RUBBER POLICEMEN, wing shape, with rubber 1% inches wide at end. Complete with glass rod 6x%6 inches ......................................................... Each .09 Per dozen .90 11557. RUBBER POLICEMEN. Same as No. 11556, but without glass rod ........... Per dozen .70 11562. RUBBER SCRAPER for scraping precipitates from the walls of beakers, etc. Hard rubber handle with soft cone shaped rubber tip ........................................... .20 11566. RUBBER SHEETING, white, 36 inches wide ................................. Per yard 1.20 RUBBER SPATULAS, see Spatulas. 11572. RUBBER STOPPERS, made from best quality of rubber especially for chemical laboratory use; will not harden from age. Each size furnished in three styles — solid, one hole or two holes. ....................................................................... Per pound 1.80 Table Showing Approximate Number of Rubber Stoppers in One Pound, Number Oft 0 17 1 18 2 20 3 4 23 | 25 5 • 6 32 : 37 8 41 9 45 10 50 11 56 12 63 13 68 Diameter small end, mm 9 12 1°0 80 15 fifl 16 !- L 42 1 33 23 ••» 26 20 I 30 15 33 !">' 3V 11 | 42 ~48~ 6' ' 53 61 Approximate f holid Number in •< 1 hole 130 90 6-> 60 45 | 35 30 21 16 13 11 8 6 5 4 One Pound 1 2 hole 138 94 70 64 47 ! 38 32 22 17 14 12 8 6 5 4 7372. RUBBER STOPPERS, especially designed for use with Moisture Testers Nos. 7360 to 7364, to stand the high temperature existing in moisture test flasks; they are necessary when copper flasks are used. No 5 6 Per dozen 1.65 2.20 RUBBER TESTING APPARATUS, see Testing Machines. 430 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. RUBBER TUBING, ALL KINDS Special Notice. Bubber Tubing of the various kinds listed comes in original 12 foot lengths from the manufacturer, and is sold only in lengths of 3 feet or multiples of 3. This enables us to avoid the waste due to short pieces of unsalable lengths and permits us to sell the tubing to our customers at a reasonable price, without the necessity of a charge to cover the loss. 11580. RUBBER TUBING, White, light wall, cloth impression. This tubing is recommended for gen- eral laboratory use where an inexpensive tubing is desired. Diameter inside, inches % %6 V* %e % % Thickness of wall, inches %4 %4 Vie He Via %4 Per foot (see Special Notice) $0.05 .07 .10 .12 .14 .24 11582. RUBBER TUBING, White, heavy wall, same quality as No. 11580. The % inch size is the standard size and quality for Bunsen burner connections. Diameter inside, inches %6 % %c % % Thickness of wall, inches %4 %2 %2 "/M % Per foot (see Special Notice) 13 .17 .20 .26 .36 11588. RUBBER TUBING, Red, Antimony, light -wall. Retains its elasticity longer than No. 11580 and is preferred by many users for this reason. Diameter inside, inches % %6 % %Q % % Thickness of wall, inches %4 %4 i/16 i/10 %4 %2 Per foot (see Special Notice) 06 .09 .12 .15 .21 .35 11590. RUBBER TUBING, Red, Antimony, heavy wall, same quality as No. 11588. Preferred by many users for Bunsen burner tubing in place of No. 11582. Diameter inside, inches %g *4 ^ % % Thickness of wall, inches %4 %2 %2 %4 % Per foot (see Special Notice) 15 .22 .27 .36 .54 11594. RUBBER TUBING, Black, pure gum, light wall, seamless. This tubing will not bloom ami in especially suited for gas analysis work. Diameter inside, inches % %6 % 9ic % % Thickness of wall, inches %4 %j Ke Vie %4 %2 Per foot (see Special Notice) 08 .10 .15 .17 .25 .42 11596. RUBBER TUBING, Black, pure gum, heavy wall, same quality as No. 11594. Diameter inside, inches %2 %Q 54 fyin % % Thickness of wall, inches %4 %4 %o %o %4 % Per foot (see Special Notice) 15 .17 .22 .27 .42 .60 11600. RUBBER TUBING, Latiruco, Black, light wall, pure gum, free from blooming, very elastic and impervious to gases. It clings to glass tubing, eliminating wiring. Especially suitable for connections to gas analysis apparatus. Each length bears the trade-mark Labruco repeated frequently. Diameter inside, inches % %, ^e V-t 5/ie % % % % 1 Thickness of wall, inches %2 %, %4 #6 }{0 %2 %2 % % % Per foot (see Special Notice) ... .06 .09 .12 .18 .24 .35 .50 .80 .90 1.15 Per 12-foot length 60 .90 1.20 1.80 2.40 3.90 5.25 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A, 431 Ho. 11624. Nos. 11600-4. No. 11626. No. 11630. 11602. RUBBER TUBING, Labruco, Black, heavy wall, same quality as No. 11600. Diameter inside, inches % %2 $ie % 9i« Thickness of wall, inches ^6 l{6 ^6 %2 %l Per foot (see Special Notice) $0.10 .12 .15 .28 .36 Per 12-foot length 1.05 1.25 1.50 2.70 3.60 11604. RUBBER TUBING, Labnico, Red, light wall, same as No. 11600, except for the color. Diameter inside, inches %%2JKe%9ie%%%%l Thickness of wall, inches fa %4 %4 He He %2 %2 % % % Per foot (see Special Notice) ... .06 .09 .12 .18 .24 .35 .50 .80 .90 1.15 Per 12-foot length 60 .90 1.20 1.80 2.40 3.90 5.25 11610. RUBBER TUBING, Pressure, Black, semi-pure gum, extra heavy wall, for filter and air pump connections, vacuum work, etc. Because of its flexibility this tubing is also useful for connec- tions to mercury leveling bulbs, nitrometers, etc. Diameter inside, inches ^6 ^4 Thickness of wall, inches ^6 ^6 Per foot (see Special Notice) .50 .60 11614. RUBBER TUBING, Pressure, cloth insertion, heavy wall, for air pump connections, etc. Diameter inside, inches ${$ *4 9i6 "•» % Per foot (see Special Notice) 12 .15 .16 .18 .22 11618. RUBBER TUBING for Gooch Crucibles, thin walled band tubing, pure gum, very elastic. Width outside when flat, inches 1% 1% 2% Width inside when flat, inches 1% 1% 2 Per foot .25 .30 .40 11624. TUBING, Flexible, Steel, with rubber packing, for connections to Bunsen burners, hot plates, etc. It is indestructible except by acids and excess of oil, is gas tight and safe from kinking or breaking. Each length is furnished with heavy rubber socket at each end. Inside diameter, % inch. Length, inches 24 36 Each 25 .35 11626. TUBING, Flexible, Steel, made entirely of metal by a new process, without rubber or other pack- ing. It is gas tight and indestructible, except by strong acids, and will last indefinitely. In- side diameter, ^4 inch per foot .30 11627. RUBBER CONNECTORS for use with No. 11626 per pair .10 11630. RUBBER TUBE and Bulb Expander, for stretching tubing and bulbs to facilitate attaching to connection tubes, pipettes, etc .50 432 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 11646 (five positions). No. 11642. No. 11640. F661. 11640. 11642. 11646. F845. 11796, RULE, Celluloid, metric and English, 6 inches long. Of white celluloid with one edge gradu- ated in mm, other edge in eighths of inches. The two scales are numbered from the same end of the rule, making easy a comparison of measurements in the two systems. This scale may easily be carried in the vest pocket Each .05 Per hundred 4.50 RULE, English and Metric, boxwood, 12 inches by 16ths on one side, millimeters on the other. Four fold, solid brass joints, with brass caliper extension for measuring diameters up to 2% inches or 70 mm. Made to carry in pocket $0.65 RULE, English and Metric, light boxwood, 36 inches by 16ths on one side, millimeters on the other. Six fold, spring joints, very convenient for comparing English and metric measure- ments. Made to carry in pocket .50 RULE, Johnson's Patent Combination. This six-inch folding pocket rule is made of spring Ger- man silver accurately and distinctly graduated; it can be used as a Hook-rule, Caliper-gauge, Protractor, Triangle or Try-square. The upper edge is graduated in 32nds, the lower edge in 16ths. The caliper blade is graduated in 16ths on one side and 32nds on the other. The pro- tractor is graduated every five degrees and is provided with a vernier reading to % degree. This handy and indispensable rule can be set to any desired angle, and the center joint is so constructed that the rule remains firm wherever set 2.50 RULES, Metric, see Scales. RULE, Parallel, see Drawing Instruments. RULES, Slide, see Slide Rules. RUPERT'S DROPS per dozen .50 SAMPLE BAGS, see Paper Bags. SAMPLE BOTTLES, see Bottles. SAMPLE BOXES, see Boxes. SAMPLE JARS, see Jars. SAMPLERS, Hand, for Coal and Ore, consisting of sampler of tin with handle, divided into par- allel troughs, and a scoop of sheet iron with band-iron handle. No A • Dimensions, inches 6x8% Width of troughs, inches Vz Number of troughs 6 Each . 2.25 B 7x9 V4 14 3.70 C 10x10 D 11x12 10 3.80 4.15 11800. SAMPLERS, Jones, for quick and uniform sampling of. ores, cement, coal, etc.; easily cleaned. Complete with hopper mounted on support, 4 sampling pans, brush and scoop. No. . : A Size, inches 6x6 Width of troughs, inches % Number of troughs 8 Each . 11-00 B 10x10 % 10 19.80 CEXTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 433 No. 11830. No. 11832. 11 002. 11804. 11808. 11810. 11812. 11818. 11S22. 11830. 11832 SAMPLER, Riffle, for reducing quantity of 4-mesh coal samples, according to specifications of the United States Bureau of Mines and the American Society for Testing Materials. With twelve divisions, each %-inch wide. Complete with four sampling pans, scoop and brush. (See Journal of Industrial and Engineering Chemistry, Vol IX, No. 1, for January 1917) 116.00 SAMPLER, Riffle, for reducing the 20 amd 60-mesh coal to a laboratory sample. Similar to No. 11802. but with twelve divisions each % inch wide. Complete with four sample pans, scoop and brush 22-00 SAMPLER, Braun Umpire Ore. for band power, for accurate and impartial sampling. Consists of a hopper mounted on a support; two buckets, each divided into four parts, two open and two closed; and a receiver. By means of gears attached to the handle the buckets are made to revolve in opposite directions; with the same motion the hopper is agitated by means of a cam and coiled spring. The sample is halved in the upper bucket and again in the lower, allowing one quarter of the original to fall into the receptacle. Kefeeding the quarter ob- tained gives ^ieth- an4ths up to s^ths. At the lower end is an inch scale gradu- ated to 64ths. Made of flexible spring steel 1^6 inches wide and 694 inches long 50 SCISSORS, see Shears. SCLEROSCOPE, see Hardness Testers. SCOOP. Agateware, 3x5% inches, with handle .20 SCOOPS. Horn, flat and wide, with square ends, for ordinary use. Length, cm 10 12 14 16 Each 15 .18 .21 .27 SCOOP, Iron, adopted by the Cleveland Iron Chemists as standard for sampling iron ores Length, 3H inches: width, 2*4 inches: depth, 1% inches; with 6% inch handle 50 SCOOP. Sampling, of heavy iron with wood handle, 5x4% inches 40 SCOOP. Tin Plate, with handle, for mixing. Length of bowl, 8 inches; width, 5% inches . .46 SCOOPS, Weighing, see Balance Accessories. 486 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 11921 2% 2000 3.00 2.25 2% 1750 3.50 2.60 11924. SCORIFIERS, Denver Fire Clay. Diameter, inches 2 Number in original barrel 2000 Per 100 $2.80 Per 100 in original barrel 2.05 SCORIFIER TONGS, see Tongs. 11930. SCRAPER, for cleaning muffles, flat end, length 36 inches 11932. SCRAPER, same as No. 11930, but with end bent SCREWS, Machine, Iron, Flat Head. In gross packages only. Length, inches ... %g % %e %%%%%! 11940 A. No. 2, per gross.. . $0.30 .30 .30 .30 .30 .35 .40 11940B. No. 4, per gross ... .30 .30 .30 .30 .30 .35 .40 .40 11940C. No. 6, per gross. .. .35 .35 .35 .35 .35 .40 .45 .45 .50 11940D. No. 8, per gross... .35 .35 .40 .40 .45 .50 .50 .55 .60 11940E. No. 10, per gross... .55 .60 .60 .65 .70 .75 .75 .80 2% 1000 4.25 3.15 .50 .50 .70 .75 1.20 1194? A-E. SCREWS, Machine, Iron, Round Head. Same sizes and prices as No. 11940. In gross pack- ages only. SCREWS, Machine, Brass, Flat Head. In gross packages only. .65 .75 .95 1.50 2.00 % .75 .80 1.05 1.65 2.25 .85 .90 1.20 1.80 2.60 Length, inches ... ^e % 40 32 40 32 24" oO .60 .60 .60 .60 J 14 % 20 60 .80 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 437 No. 11978. No. 11982. No. 11970. No. 11988. No. 11994. 11964. SCREW DIES, round, adjustable. Xo A B C D Diameter of die, inches 1 1%« 2% Diameter of screw, inches Vt % % % No. threads to inch 20 16 12 10 Each *L10 L10 1.50 3.00 11965. SCREW DIE STOCK, for holding Xo. 11964 Dies. Xo ABC For die of diameter, inches 1 l^ie 2% Each 1.80 3.70 4.00 11968. SCREW DIE AND TAP SET, with stock 7 inches long, tap wrench 7% inches long, 6 dies i^6 inch diameter and 6 taps cutting threads 4-36, 6-32, 8-32, 10-24, 12-24 and 14-20. Set is en- closed in neat hardwood case 8.00 11970. SCREW DIE AND TAP SET, with stock 9 inches long, 5 dies 1 inch in diameter, and 5 taps cutting threads ^4-20, %6'18> %-l*>, vie-14 and %-12. Set is enclosed in neat hardwood case. 12.50 11978. SCREW DRIVERS, with steel blade in wooden handle. Length, inches 4 8 Each 20 .35 11980. SCREW DRIVER, rosewood handle and finest steel blade, elegantly polished throughout. Es- pecially adapted for instrument use. Indispensible to the laboratory. Length over all, 5% inches; length of blade, 2 inches; width of blade, % inch .40 11982. SCREW DRIVER, Jewelers', of steel, nickel-plated, with blade i^6 inch in width. Length over all, 31! inches .25 11984. SCREW DRIVER, Ratchet, a high grade tool. Blade and ratchet mechanism made of oil tem- pered tool steel; changes from right to left are made by turning the knurled ferrule. Length of blade, 6 inches; width of blade, >4 inch 1.10 11988. SCREW DRIVER POCKET SET, with 3 blades of assorted sizes and 1 reamer for making or en- larging holes. When not in use the blades are kept in the hollow handle. 314 inches long when closed; polished and nickel-plated .90 11994. SCREW EYES, of bright wire. Xo 214 12 7 Length, approx., inches % 1 IV, Per dozen ., 05 .07 .12 438 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 12000. No. 12001, No. 12026. 11996. 14 SCREW HOOKS, of bright wire. No Length over all, approx., inches Per dozen $0.06 SCREW PITCH GAGE, see No. 6486. 12000. SCREW TAPS, standard. . A 2 No. 12032. 12 11/3 .08 10 2 .09 8 2V* .12 B 4 C I D 6 E 8 G 10 H 12 %2 24 .26 J 14 20 .45 N % 10 1.20 No Screw gage No Approx. diam., inches %4 %4 %4 %4 %2 %, %6 No. threads to inch 56 36 32 40 32 40 32 Each 44 .30 .26 .26 .26 .26 .26 No K L M Diameter, inches 14 % % No. threads to inch 20 16 12 Each 45 .55 .70 12001. SCREW TAP WRENCH, for taps %-inch and smaller 1.50 12002. SCREW TAP WRENCH, for taps % to %-inch 2.00 12010. SEA SAND for cleaning platinum ware per pound .10 SEALING WAX, see Wax, Sealing. SELENIUM CELLS, see Catalog F of Physical Apparatus. F7365. SEXTANT, Metal Model, full size, with which quite accurate work is possible. The main scale is graduated in 20 minute divisions and may be read to 30 seconds by means of the vernier on the index arm. Complete with mirrors, mirror mountings, sight tube, handle and logs for support 22.50 SHAKING APPARATUS 12026. SHAKING APPARATUS, Camp's (Patented), used extensively by the United States Steel Cor- poration and other steel and iron laboratories for the rapid precipitation of phosphorus by the molybdic acid method, and for dissolving steel or pig iron for carbon combustion. The disk is made to hold six flasks, Erlenmeyer or Florence shape, from 6 to 24 ounces capacity. Power required to operate, about i^5 h. p.; diameter of pulley, 6 inches; proper speed of operation, 100 to 140 r. p. m 27.50 12028. SHAKING APPARATUS, Camp's, same as No. 12026, but with wooden disk and clamps for twelve volumetric flasks of 100 cc capacity. Widely used in sugar analysis 35.00 12032. SHAKING APPARATUS, Chest of Drawers Design, with polished hardwood chest containing six drawers, with a capacity of eight 250 cc bottles each. Requires % h. p. motor to operate. Complete on hardwood base with enclosed gear but without motor 75.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 439 !No. 12038. No. 12048. No. 12040. No. 12049. 12038. SHAKING APPARATUS, Electric, for four bottles. Constructed of heavy cast iron making it strong and rigid, with ball bearings affording smoothness of motion. The clamps will take ordinary bottles from 200 to 1000 cc, and by means of blocks, smaller bottles and tubes may be held. The speed may be varied according to the load; for four 100 cc bottles, 300 r. p. m. should be used; for small bottles about 600 r. p. m. No A B C D A.C. D.C. For volts 110 220 110 220 Each $134.40 134.40 129.60 129.60 12040. SHAKING APPABATUS, Electric, similar to No. 12038, but for two bottles or tubes up to 50 cc capacity. Especially suited for sputum work. The speed is about 1000 r. p. m., subjecting the bottle contents to very vigorous shaking. No A B C D A.C. D.C. For volts 110 220 110 220 Each 84.00 84.00 78.00 78.00 12041. HEAD for No. 12040, to take two Erlenmeyer flasks of 150 cc capacity 14.40 12042. HEAD for No. 12040, to take four 50 cc bottles or tubes, at a maximum speed of about 800 r. p m 28.80 12048. SHAKING APPARATUS, Electric, Rickard's, for Sputum Bottles, very convenient for labora- tories examining many samples each day, as in Boards of Health. Arranged for shaking samples in the original collection bottles, thus obviating danger of confusion or contamina- tion If it is considered desirable to centrifuge the sputum in the same bottle, this may be done by using No. 2735 Sputum Bottle Carrier with Heads Nos. 2681 of 2685 and Centrifuges Nos. 2670 or 2696. With variable speed control for motor. Maximum speed with 24 bottles, about 600 r. p. m. Without bottles. No A B C D A.C. D.C. For volts 110 220 110 220 Each 134.40 134.40 129.60 129.60 SPUTUM BOTTLES for No. 12048, see No. 2757. 12049 HEAD for No. 12048 to take four bottles up to 1000 cc, for use in place of 24 sputum bottle head 57.60 440 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 12084-5. Nos. 12086-7. No. 12078. No. 12076. 12054. SHAKING APPARATUS, Horizontal Form, for single bottles up to five gallons capacity. With speed reducing gear from which three speeds may be obtained. Can be operated by % h. p. motor. Without motor $47.50 12056. SHAKING- APPARATUS, Horizontal Form, same as No. 12054, but for two bottles up to five liters capacity 48.00 12058. SHAKING APPARATUS, Horizontal Form, same as No. 12054, but for four bottles up to two liters capacity 50.00 12060. SHAKING APPARATUS, Horizontal Form, same as No. 12054, but with two hardwood trays, with a capacity of eight 250 cc bottles each 52.50 12066. SHAKING APPARATUS, Kent Laboratory Type, for 3 bottles up to 2000 cc 60.00 12070. SHAKING APPARATUS, Massachusetts Institute of Technology Form, for eight 250 cc bottles. Especially adapted for use in solubility determinations, conductivity work, etc 50.00 12076. SHEARS, Paper, high grade steel. Length of blades, inches 6 8 Each 1.40 2.50 12078. SHEARS, Tinners' Snips, for cutting metal. Length of cut, 2% inches 90 SHEARS, Pruning, see Catalog A of Agricultural Apparatus. SIEVES SIEVES, Brass Frame, seamless, brass gauze (for Covers and Bottom Pans see Nos. 12102 and 12104). Mesh 10 20 40 60 80 100 200 12084. Each, 5 inches in diameter 1.25 1.25 1.40 1.45 1.50 1.90 3.20 12085. Each, 8 inches in diameter 1.90 2.20 2.25 2.35 2.50 3.00 5.50 SIEVES, same as Nos. 12084 and 12085, in sets of five, one sieve fitting on top of another, with one cover and one bottom pan; set consists of 20, 40, 60, 80 and 100 mesh. 12086. Per set, 5 inches in diameter 8.50 12087. Per set, 8 inches in diameter 13.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 441 No. 12090. No. 12096. No. 12102. !^AL SCIENTIFIC No. 12104. No. 12098. No. 12110. No. 7398. 12090. SIEVES, Brass Frame, seamless, having sheet brass bottom with circular perforations. Exten- sively used in soil analysis and seed testing. Diameter, 5 inches. Diameter of perforations, mm % 1 2 3 5 Each f $1.40 1.35 1.30 L30 L30 12091. SIEVES, complete set of five of No. 12090, with brass cover and bottom pan 8.50 12092. SIEVES, set same as No. 12091, with 3 mm and 5 mm sieves omitted 7.25 For Cover and Bottom Pans see Nos. 12102 and 12104. 12096. SIEVE FRAME, same as No. 12090 without bottom pan, but with brass ring for holding bolt- ing cloth. Diameter, 5 inches - 1.00 12098. BOLTING CLOTH, Silk, for making sieves, etc., of standard weight, 40 inches wide. No 2 5 7 9 11 13 15 18 20 25 Mesh per linear inch.. 52 64 80 96 116 130 148 168 173 200 Per linear foot 2.40 2.80 3.00 3.20 3.80 4.60 5.40 7.20 10.00 11.00 12102. COVERS for Nos. 12084 to 12096. Diameter, inches 8 Each 50 .60 12104. BOTTOM PANS for Xos. 12084 to 12096. Diameter, inches 5 8 Each 50 .60 12110. SIEVES, Bureau of Soils Type, as employed in the Laboratories of the Bureau of Soils, Washing- ton, D. C., for mecuanical analysis. Set of four sieves turned from heavy brass castings with bottom pan and cover, each about 2 inches in diameter by 1 inch high, perfectly fitted, so that the set may be well shaken without coming apart. Shaped so that there is no loss of the sample, a great advantage where small samples are being tested. Sieves proper are readily re- placeable; upper two of brass, with perforations 1 mm and 0.5 mm in diameter; lower two of bolting cloth 64 and 130 mesh per set 10.00 For Shaker for Xo. 12110 Sieves, see Xo. 12148. 12114. SIEVES, Cement, Bureau of Standards Typa, Brass Frame, seamless, of woven brass screen, 20 cm in diameter and 6 cm high, with certificate of the United States Bureau of Standards. No A B Mesh 100 200 Size of openings, inches 0.0055 0.0029 Each 8.00 15.00 7398. SIEVES, Corn Test, according to specifications of the United States Department of Agriculture. The set consists of one sieve with 14/64 inch round holes, and one bottom pan, of aluminum, 13 inches in diameter by 3 inches deep .- 4.50 12120. SIEVES, Sand, Bureau of Standards Type, Brass Frame, seamless, of woven brass screen, 20 cm in diameter and 6 cm high, with certificate of the United States Bureau of Standards. No A B Mesh 20 30 Size of openings, inches 0.0335 0.0223 Each 6.25 6.25 442 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 12140. Nos. 12136-7. No. 12128. No. 7402. No. 12148. 12124. SIEVES, Standard, Brass Frame, seamless, brass gauze, according to the specifications of the American Society for Testing Materials; diameter, 8 inches. Mesh 10 20 30 40 50 60 70 80 SO 100 Each $3.70 3.00 3.00 3.00 3.25 3.25 3.40 3.70 4.00 4.30 Mesh 110 120 130 140 150 160 170 180 190 200 Each 4.45 4.60 4.95 5.20 5.50 5.80 6.40 7.00 7.35 7.60 12125. 12128. 7402. COVERS AND BOTTOM PANS for No. 12124 per set 2.00 SIEVES, Standard, Tin Frame, seamless, brass gauze, similar to No. 12124, but nested in set of 8, from 5 to 8% inches in diameter consisting of one each 10, 20, 30, 40, 50, 80, 100 and 200 mesh 24.00 SIEVES, Wheat Dockage, according to Government specifications, a set of four sieves, 13 inches in diameter, and bottom pan, constructed of aluminum, telescoping. Consists of a buckwheat sieve with 8/64 inch triangular perforations; a fine seed sieve with 1/12 inch round perfora- tions; a scalper sieve with 12/64 inch round perforations; and a chess sieve with perforations 41/£/64 by Vs inch. (See Regulatory Announcement No. 2 of Federal Wheat Grades Effective July 1 and August 1,1917) 8.00 SIEVES, Wood Frame, brass gau/e. Mesh 20 40 60 80 100 200 12136, 12137, 12140 Each, 6 inches in diameter 50 Each, 8 inches in diameter. .60 .60 .65 .75 .80 .90 1.00 1.10 1.25 3.20 3.50 SIEVES, Wood Frame, consisting of a heavy wooden frame provided with a slot in which may be placed bottoms of perforated steel, and hinged at one end to facilitate removal and replace- ment of these metal bottoms. Inside dimensions of frame, 17% x 14 x 5 inches. Ten bottoms are included with perforations of %, *4, %, %, 1, 1*4, 1%, 2, 2%, and 3 inches 18.00 12148. SIEVE SHAKER, for Power, for use with No. 12110 Sieves. A motor of 1/20 h. p. is mounted on the same base with an eccentric shaft, to which it is belted. The set of sieves is clamped in a frame at the end of a long lever arm which rests on the eccentric. This lever arm is so at- tached to the eccentric that with each revolution of the cam the sieves are struck sharply, raised and dropped with a motion similar to that used in shaking by hand. Without sieves. (See Bulletin No. 84, United States Department of Agriculture, Bureau of Soils.) No A B C D A.C. D.C. For volts 110 220 110 220 Each 50.00 51.00 45.00 46.00 CENTRAL SCIENTIFIC CO., CHICAGO, II. S. A. 443 Nos. 12152-3. 1J].")L'. SIEVE SHAKER, Ro-Tap, Electrically Driven. This machine reproduces the circular and tapping motions of hand sieving, with a uniform mechanical action, which produces reliable results and standardizes laboratory methods. Ruggedly constructed with heavy base and substantial sup- porting columns. Running parts operate in oil. By means of No. 12153 Stop-Rite Time Switch, the process may be made entirely automatic, as the switch may be set for any desired time interval, and the test will be automatically stopped at the end of that time. Capacity of the machine, 6 standard height 8 inch sieves with bottom pan, or 13 half standard height sieves with bottom pan. Complete with direct connected 110 volt motor, but without sieves or Stop- Kite Time Switch. No A B CD A.C. D.C For volts . .». 110 220 110 220 Each $200.00 205.00 200.00 200.00 12153. STOP-RITE TIME SWITCH, for use with No. 12152 Ro-Tap Sieve Shaker. May be set for any desired interval and will automatically stop machine at the end of the pre-determined period 20.00 12158. SIFTER, Lightning No. 0, for hand power. Complete with one sieve of any mesh up to 50 9.00 In ordering, kindly state mesh of sieve desired. 12166. SILICA RODS, Opaque Fused Silica, for use in stirring fusions and high temperature mixtures. In lengths up to 5 feet. Diameter, mm 1-2 3 4-5 6-7 8 9-10 Per foot 50 .63 .94 1.25 1.56 1.75 SILICA TUBING, Opaque Fused Silica, glazed at the ends and smooth inside. Sizes up to % inch have satin finish. Very resistant to sudden changes of temperature. For combustion work, the glazed Combustion Tubing No. 3186 glazed inside and outside and gas tight should be selected. In lengths up to 8 feet. In ordering specify diameter and thickness of wall. 12168. 12169. 12174. 12180. Diameter, inside, mm.. 3 4-5 6-7 8 9-10 12-13 15-16 19 22 Thickness of wall, mm. .5-2.5 .5-2 .5-2 .5-2 1-2 1-2 1-2.5 1-3 1-3 Per foot 56 .94 1.13 1.38 1.88 1.88 2.19 2.63 2.88 For one end closed, per tube, add 19 .25 .25 .25 .31 .31 .44 .63 .81 SILK, Oiled, in sheets 12x14 inches, each in a box Per sheet SIPHONS, Glass, plain form. No. Length of delivery tube, inches Each 12182. SIPHONS, Glass, with suction tube. No Length of delivery tube, inches Each 12184. SIPHONS, Glass, with suction tube and stopcock. No Length of delivery tube, inches Each . A 12 .40 A 12 .70 A 12 2.50 B 18 .50 B 18 .80 B 18 2.75 25 1-3 3.13 .94 .45 C 24 .60 C 24 .90 C 24 3.00 444 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 12196. No. 12200. SLEEVES, see Aprons, Oversleeves and Laboratory Coats. SLIDES, Microscopic, see Microscope Accessories. SLIDE BOXES, see Microscope Accessories. 12190. SLIDE RULE, Woodworth, a simple machine for multiplying and dividing. It is printed on heavy bristol board, ready for the student to cut and fit together. Recommended by the Cen- tral Association of Science and Mathematics Teachers Each $0.10 Per dozen 1.00 12192. SLIDE RULE, Mannheim, 10-inch, graduations on white paper, with a protective coating, mounted on hardwood 1.40 12194. SLIDE RULE, Mannheim, fine quality, 10-inch, in case with book of instructions 4.00 12196. SLIDE RULE, Multiplex, 10-inch, useful in solving all arithmetical, trigonometrical, and log- arithmetical problems which are possible with the Mannheim, and has also the following char- acteristic advantages: Multiplication of three numbers in one setting; division of one number by two numbers in one setting; more convenient solution of inverse proportion; direct solu- tion in a single setting of a series of divisions with constant dividend; direct reading of cubes and cube roots; direct reading of three-halves and two-thirds powers; direct solution in a single setting of many combined operations. In case with book of instructions 6.25 12200. SLIDE RULE, Chemists' Duplex, 10 inches in length, engine divided. The rule carries 138 chemical symbols which include the common acids, bases, salts, oxides, and elements em- ployed by the average chemist. As each symbol has its individual position corresponding to the logarithm of its molecular weight, the number of permutations and combinations pos- sible covers the requirements of almost any problem. By using the logarithmic and cologarith- mic scales in conjunction with the chemical gage points, problems in Stoichiometry, such as Gravimetric Analysis, Volumetric Analysis, Equivalents, Percentage Composition, Conversion Factors, Volume of Gas from a given weight of substance at different temperatures and pres- sures, and many other analogous problems are readily solved. Aside from the solution of the chemical problems above referred to any arithmetical problems solvable by logarithms are readily and accurately done with a minimum number of settings. With glass indicator, in morocco covered case with full directions 8.00 SNIPS, Tinners', see Shears. 12210. SOAP, Green Oil, U. S. P. Quality, a soft soap of potash base with strongly detergent properties. Widely used for antiseptic purposes in connection with surgical and bacteriological work. Useful for many purposes around the chemical laboratory, such as cleaning glass and porce- lain, desk tops, sinks, stained hands, etc. In concentrated form, for solution in water. No A B C Style package jar can pail Weight, pounds 1 2 5 Each 60 .95 1.90 SOAP, Palm Oil, see No. 8952. SODIUM SPOONS, see Spoons, Sodium. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 445 No. 12228. No. 12234. SOIL ANALYSIS APPARATUS INCLUDING APPARATUS FOR PHYSICAL PROPERTIES OF SOILS (Arranged Alphabetically.) 12220. ABSORPTION APPARATUS, Heat, for absorption of heat by soils, as described by Steven- son & Schaub. This apparatus is nsed to compare the temperatures of various soils at differ- ent depths when the soils are exposed to the direct rays of the sun, and consists of four zinc boxes 4x4x8 inches deep, enclosed in a wooden box open at the top $5.00 12222. ABSORPTION APPARATUS, Moisture, for determining the power of dry soils to absorb hygro- scopic moisture from a saturated atmosphere. A water-tight, water-proofed substantial wooden box with heavy cover so designed that it may be clamped air-tight to the box. (A metal box is not satisfactory, because it is so affected by temperature conditions that the results obtained have little or no value.) Wooden strips, not shown in the illustration, sup- port the soil pans and have a device for holding the strips of absorption paper which by capillary action absorb water, keeping the air within the box in a saturated condition. Com- plete with six soil pans 17.50 SOIL PAN of zinc, 6%x6%xl% inches, as used in Xo. 12222 Absorption Apparatus. These pans are water-tight and will be found convenient for use in drying ovens. Each 30 ASPIRATOR, McCall, for studying the rate of the flow of water through soils of different tex- tures. This aspirator has no moving parts to cause errors from friction and the method of operation is exceedingly simple. The bottle is first filled with water to a definite mark on the scale and connections are made as shown in the illustration. The pincheock is then opened and water allowed to run from the bottle until it stands at a much lower level. By noting the time required with different soils, the relative rate of flow is readily determined. Complete as illustrated, with metal support, but without soil tube or beaker 8.00 SUPPORT only of No. 12228 3.00 ASPIRATOR BOTTLE only of No. 12228. Complete with rubber stoppers, rubber tubing, and pincheock 5.00 ASPIRATOR, for determining the comparative porosity of soils by measuring the rate of flow of air through them under constant pressure. This apparatus consists essentially of a closed pressure chamber formed by a rubber diaphragm or bag placed between a movable weight and a wooden base 15 inches in diameter. To the weight is attached a graduated rod, by reference to which definite quantities of air may be forced through the different soils under consideration. The pressure chamber is enclosed in a suitable casing for protection.. 17.50 12223. 12228. 12229. 12230. 12234. 446 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 12238. No. 12242. AUGERS, see Soil Sampling Apparatus. BINS OE CONTAINERS for Soil, see general heading Bins or Containers. 12238. BOTTLE, Mechanical Analysis, convenient for separating soils into their constituent parts, as described in Hosier and Gustaf son's "Soil Physics Laboratory Manual." Complete with in- verted rubber stopper and tubes $0.75 CARBONIC ACID APPARATUS, see general heading Carbon Dioxide Determination Apparatus. 12242. CENTRIPUGE, Soil, for preparing soil samples for Mechanical Analysis. This machine is of excellent design, having features suggested by agronomists. The motor is mounted with shaft vertical, thus obviating considerable vibration and allowing easy access to the soil tubes. A brass trunnion arm, mounted on this shaft, carries eight soil tubes, which are of heavy well annealed glass and are encased in aluminum sheaths. These sheaths are held in trunnions to the trunnion arm by hardened steel bearings. The whole is protected by a metal covering, which extends to the floor or table on which the motor rests, access to motor and tubes being gained by means of a hinged cover. Complete with % h. p. motor, of 1800 r. p. m. no load speed, ready for mounting on a table top, and eight soil tubes. No A B C D A.C. D.C. For volts 110 220 110 L'i'O Each 100.00 95.00 110.00 12243. EXTRA SOIL TUBES, heavy glass, as used in No. 12242 each .15 per dozen 1.50 12246. CENTRIFUGES, International, Electric, with equipment for mechanical analysis of soils, including speed control rheo- stat; No. 2685 Eight-tube Head; eight No. 2710 Metal Tubes, 100 cc, with No. 2711 Trunnion Kings; eight No. 2718 Eubber Cushions; 72 No. 2716 Plain Glass Tubes, 100 cc; and an 8-tubo Hack. Dimensions: 23 inches high, closed; 35 inches high, open; and 24 inches in diameter, with a shipping weight of about 300 pounds. No A B C D A.C. D.C. For volts . . 110 220 110 220 Each 138.00 138.00 108.00 108.00 2716. TUBES, Glass, plain, lipped, 100 cc, for No. 12246 Centrifuge, .per dozen $2.30 No. 12246. CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 447 No. 12252. 12252. CENTRIFUGES, Moisture Equivalent, Briggs-McLane, as described in the Proceedings of the American Society of Agronomy, Volume 2, 1910. This centrifuge is used for determining the relative moisture equivalents of soils where the term moisture equivalent designates the maximum percentage of moisture which a soil can retain in opposition to a known centrifugal force. For a standard of comparison, a centrif- ugal force equal to 1,000 times the force oi gravity has been adopted. In making the deter- minations, the soils, suitably moistened, are placed in cups with perforated bottoms. These cups are then placed in the cylinder of the centrifuge and rotated at a constant speed, so chosen as to develop the required centrifugal force. "Each soil now loses water until the capillary forces have increased sufficiently to balance the centrifugal force acting on the soil moisture. Since the moisture content of each soil which has been treated in this way is in capillary equilibrium with the same force, it follows that if these moist soils are placed in contact in any order whatever no movement of water from one soil to another will take place. A condition of complete equilibrium exists throughout the series of soils thus treat- ed." It is then necessary only to determine the moisture content of each soil correspond- ing to this condition of equilibrium in order to determine its quantitative position in the scale of moisture retentiveness. The centrifuge here described is capable of maintaining the required centrifugal force well within the desired limit of accuracy. The instrument consists of a bronze disk cylinder containing 16 soil boxes with wire gauze bottoms, and attached to the shaft of a vertically mounted D. C. motor. The motor is pro- vided with a Kellogg Constant Speed Governor and a Frahm Tachometer (not shown in the illustration) is supplied which has a range from 2380 to 2500, thus bringing the desired point of speed, 2440 r. p. m., about the middle of the dial. If alternating current only is avail- able, a motor-generator set should be used to produce the direct current necessary. See Nos. 4824 to 4848. Complete as described. Xo A B For volts 110 220 Each $285.60 285.60 For other CENTRIFUGES, see general heading Centrifuges. COLORIMETERS, see general heading Colorimeters. 1225fi. COMPACTING MACHINE, designed for obtaining uniform compaction of soils in tubes 18 inches or less in length and four inches or less in diameter. It consists of two uprights hav- ing sockets at their lower ends for attachment to the floor and a cross bar with wall attach- ments at their upper ends. A cross bar fastened rigidly to these uprights carries a rotating tube socket or holder which is rotated by means of a crank. Twice during each revolution the tube is raised to the height of *4 inch by means of inclined surfaces under the tube holder, and automatically dropped, which process jars the soil into position. A small propel- ler is attached to the end of the rod extending down from the sliding cross bar. This pro- 448 CENTRAL SCIENTIFIC CO., CHICAGO, IT. S. A. No. 12268 No. 12264 v^- tj No 12272_ COMPACTING MACHINE, Continued. peller is placed at the bottom of the tube to be filled and soil then poured into the tube. Twice during each revolution it drops with the soil tube, thus striking a definite number of blows on the soil column as it rises. This compactor is built to compact soils to approximately the same condition in which they are found in the fields and to give uniform compaction for comparative tests. It is simple in principle and does its work quickly and easily. With two propellers (one for 2-inch tubes and the other for 4-inch tubes), weight holder, and weights $30.00 12258. COMPACTOE, Spring Board, necessary for compacting soils in glass tubes. Base of wood 8x24 inches; spring board firmly fastened to base at one end; massive slip-weight slides on nickel- plated rod. A very substantial and well-finished piece 7.00 12262. CONDUCTIVITY APPARATUS, for determining the thermal conductivity of soils. This design has been modified from the original design in use at the University of Illinois Soils Labora- tory. A galvanized iron soil tray, 16x4x5 inches, has at one end a water-tight boiling tank, 4x4x5 inches. Attached to this tank is a heating coil, as shown in the illustration, by which the water in the tank can be kept at the boiling point indefinitely. By this method of heat- ing, the errors present in the old apparatus due to direct heating from the flame are entirely avoided. The boiling tank is provided with tubulatures for thermometer and for reflux con- denser which may be used if desired. Complete as illustrated 6.00 32264. CONDUCTIVITY APPARATUS, similar to No. 12262, but without heating coil and with an electrical heating unit. This method of heating was suggested by the Department of Soil Technology of the New York State College of Agriculture at Cornell University and has proved very satisfactory. For 110-volt current, either alternating or direct. Power consumed, 350 watts 11.00 For CONDUCTIVITY BRIDGE, see No. 12400. 12268. DIGESTION CUP, porcelain, for acid digestion of soils (Hilgard's Method). Capacity, 50 cc .35 DISHES, Moisture, see general heading Dishes. 12272. DRAINAGE AND WATER TABLE APPARATUS, Graham & McCall's, designed to show the behavior of capillary and free water in the soil, and the principles involved in the proper construction of a barnyard to prevent loss of plant food; of copper, 3x6x12 inches high, with a solid bottom to represent hard clay or stone. Through the vessel are two brass tubes, sawed transversely, which communicate with the outside, representing tile drains at different depths. A standpipe shows the height of free water inside the vessel. To operate, fill the vessel with soil and pour on water at regular intervals, giving it time to soak into the soil. The water, instead of coming out at the tubes, will pass downward through the soil until the solid bottom is reached, when a water-table of free water will be formed at a height indicated by the free water in the glass standpipe. When the free water has risen to the first opening it will pass outside the vessel, thus proving that a tile drain placed as low as soil conditions will permit removes free water before one placed not so deep. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 449 No. 12278. No. 5644. No. 12282. No. 12286. No. 12276. DRAINAGE AND WATER TABLE APPARATUS, Continued. Some Things Which the Apparatus Will Show: Tile drains do not remove capillary water. A deep drain removes the first water. Xo water is removed until the soil at the drain line is beyond the point of saturation. The volume of soil available for plant food is greater in a drained soil. The volume of soil retaining capillary water is greater where the drains are deep. Plant food would not be wasted by leaching from a barnyard having a tight floor of elay or cement and some kind of retaining wall around the outside $7.50 DRYING OVENS, see general heading Ovens. 5644. ELUTRIATING FLASK, Benningsen's. The bulb has a capacity of about 400 cc, and the neck is graduated to 40 cc in 1 ce divisions 1.50 12270. EVAPORATION GAGE, micrometer screw form, for measuring rate of evaporation, as described in Bigelow's "Manual for Observers in Climatology and Evaporation" (TJ. S. Weather Bu- reau Xo. 409). A micrometer screw is mounted on a cap suitable for supporting it on the top of a still well 3 inches in diameter. The screw proper is 5 inches long with 20 threads to the inch. The micrometer head is graduated in 50 divisions so that readings may be taken to *iooo °f an inch. For convenience in reading a linear scale graduated in 20ths of inches is provided. The total distance from the head to the end of the pointer, which is of incorrod- ible material, is 12 inches. The pointer may be unscrewed and a hook screwed in its place, thus making the instrument serve as a hook gage. Complete as described, with pointer and hook 12.00 1227S. EVAPORATION TANK for use with Xo. 12276 Evaporation Gage, of heavy galvanized iron 6 feet in diameter by 2 feet deep. A still well 3 inches in diameter is firmly attached to one side of the tank and connected with the tank at the bottom by a galvanized pipe of sufficient size to allow free flow of water between the tank and still well 50.00 Note. — Tanks of different dimensions can be furnished if desired. 12282. EVAPORIMETER, for determining the amount of water evaporated from the surface of various soils in a given time; for determining the effect on evaporation produced by different fertil- izers, and different methods of cultivation. It consists of a brass tube 4 inches in diameter and 9 inches long having a perforated metal bottom to allow free ingress of water. This tube fits" into a water-tight spun brass base. In operation the tube is filled with soil which is compacted by means of the Soil Compacting Machine (Xo. 12256). It is then placed in position in the base. Water of known weight is placed in the base whence it passes through the perforated bottom of the tube to the soil and is evaporated from its surface. The apparatus is entirely of brass, durably made, highly polished and lacquered 5.00 12283. EVAPORIMETER, same as Xo. 12282, but with brass tube 18 inches long 5.50 12286. EVAPORIMETER, for finding the co-efficient of evaporation from soils. The soil container is of copper with brass bottom perforated with one millimeter circular openings. This container is placed in a copper water jacket 3x8 inches 3.50 450 CENTEAL SCIENTIFIC CO., CHICAGO, TT. S. A. No. 12290. No. 12298. No. 12302. No. 12308. FILTERS, Soil, see general heading Filtering Apparatus. FURNACES, Muffle, see general heading Furnaces. 12290. LIMESTONE TESTER, Hopkins, for determining the purity of limestone. The outfit consists of two glass vessels joined together, one for holding the limestone sample, the other for the charge of acid. The apparatus is light and easily weighed. (See Bulletin No. 194 of the Uni- versity of Illinois Agricultural Experiment Station) $3.50 For other LIMESTONE TESTERS, see Carbon Dioxide Determination Apparatus. MICROSCOPES, see general heading Microscopes. MILLS, Grinding, see Crushing and Grinding Apparatus. MOISTURE DISHES, see general headings Boxes, Dishes. 12298. MULCH CYLINDER, McCall's, for determining the effect of mulches upon the rate of evapora- tion from soils. Design as illustrated; of galvanized iron, 19 inches high; approximate diam- eter at top 4 inches; at bottom 8 inches 2.80 12300. MULCH CYLINDER, McCall's, same as No. 12298, but 29 inches high 3.00 12302. MULCH CYLINDER, Stevenson & Schaub's, of galvanized iron 11 inches in diameter by 13 inches high, with water supply tube 1.60 NITROGEN DETERMINATION APPARATUS, see general heading Nitrogen Determination Apparatus. 12308. ORGANIC MATTER DETERMINATION APPARATUS, for determination of organic matter in soils by the wet combustion method. Consists of two flasks, two Mohr-Geissler Potash Bulbs, one Peligot Tube, two Winkler 's Spiral Potash Bulbs, Condenser, Dropping Funnel, rub- ber stoppers and connecting tubes. (See Bulletin 24, U. S. Bureau of Soils) 13.50 10932. POTASH TUBE, Peligot (A) 40 10938A. POTASH BULB, Winkler's, 100 mm (B) 2.00 10916. POTASH BULB, Mohr-Geissler (C) 1.50 5550B. FLASK, Potassium Hydrate, 200 cc (D) 22 5550C. FLASK, Round Bottom, 300 cc (E) 28 6160B. FUNNEL. Separatory, 60 cc (F) 1.45 3224C. CONDENSER, 15 inch (G) 1.40 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 451 No. 12324. No. 12336. 12314. 12316. 12318 12324 ORGANIC MATTER JAR. A 1-gallon glass jar provided with a round hole for drainage, 1 cm in diameter, located 1 cm above the bottom $0.75 PAN, of metal, water tight, 4^4x4*4x1% inches. For use in Drying Ovens 25 PAN, of zinc, 6^x6^x1% in., as used in No. 12222 Absorption Apparatus. These pans are water tight and will be found convenient for use in drying ovens 30 PAN or BOX, of zinc, 4x4x4 inches, for volume-weight experiments 50 SAMPLE CANS OR BOXES, see general heading Boxes. PENETROMETER, for determining the firmness of soil due to its cohesion, by means of the resistance offered to the introduction of a sharp instrument. The apparatus is essentially as described in the Bulletin referred to, but is supplied with a device for making electrical con- tact when the soil has been penetrated to the desired depth, as suggested by Prof. Charles F. Shaw of the University of California. Complete as illustrated. (See Bulletin No. 50, Bureau of Soils) 50.00 12328. PERCOLATION APPARATUS, McCall's, for determining percolation of water through soils. Glass percolator, 1% pint, with brass extension having lateral tubes. Complete with rubber gasket, copper gauze, etc 6.50 PERCOLATORS, see general heading Percolators. PESTLE, Rubber, for preparing soils for analysis; 7 inches long, wood handle with rubber tip 30 PLASTICITY APPARATUS, for determining the effects of lime on plastic soils. Consists of a clamp with two knife edges about 4 inches apart, across which the briquet to be tested is placed for breaking, a heavy canvas bag for holding weights and shot and one No. 12337 Mold, 5 inches long, 1 inch wide and % inch deep, as illustrated. For those who wish a mold of more accurate dimensions, the purchase of No. 12338 Mold is recommended. (This design has been developed from the original in use at the University of Illinois, in co-operation with the Soil Physics staff of the University) • 2.50 MOLD only o'f No. 12336 ., 25 MOLD, improved form, for No. 12336, as suggested by A. F. Gustafson of the University of Illinois. Of cast brass, accurately milled to shape. All molds are therefore identical and always occupy the same position on the table, so that the bricks of soil obtained are accurate and uniform in shape. Inside cross section % square inch, length, 5 inches 1.00 12332 12336 12337. 12338. 452 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 12342-3. Nos. 12346-8. No. 12350. No. 12351. No. 12354. SOIL SAMPLING APPARATUS 12342. 12343. 12346. 12348. 12350. 12351. 12352. 12354. SOIL AUGER for obtaining soil samples. Length 36 inches with graduations every 6 inches; handle detachable; steel cutting edge 1% inches in diameter. The length may be increased to 72 inches by the insertion of No. 12343 Extension. Complete with handle but without additional length $3.50 EXTENSION of 36 inches for use with No. 12342 1.00 SOIL AUGER, improved form with stem and handle of smooth finished steel. The handle is attached by means of a lock nut of new design which entirely does away with the loosening and tightening up at the joint which has caused so much difficulty in the earlier types of Soil Augers. This Auger has been made 24 inches long for convenience in carrying when in the field. For use at greater depths extensions 2 feet long and 4 feet long have been provided. (See Nos. 12351 and 12352.) The auger bit is 1% inches in diameter and the stem is gradu- ated every 6 inches. This is a thoroughly high-grade tool for the most exacting service 7.50 SOIL AUGER, same as No. 12346 but with auger bit 2 inches in diameter 9.00 SOIL AUGER, with Sleeve, for use in dry soils. This Auger is the same as No. 12346 except that it is provided with a steel sleeve wh.ch fits over the auger bit, resting on a projection at the lower end so that the diameter of the cutting edges is larger than the outside diameter of the sleeve. This sleeve is held firmly in position at the upper end by an ingenious lock- ing device and serves to hold in position the dry soil which otherwise would not cling to the Auger when removed from the ground. 2 feet long, graduated every 6 inches. Complete with sleeve and handle 9.00 EXTENSION, for use with Nos. 12346 to 12350 Soil Augers. Complete with lock nut. Exactly 24 inches long and graduated every 6 inches 3.00 EXTENSION, for Nos. 12346 to 12350 Soil Augers. Same as No. 12351 but exactly 48 inches long 4.00 SOIL AUGER, Nebraska Design, designed for general work in soil investigation; especially adapted to work where samples at exact depths are desired, since with this instrument it is possible to secure samples of soil one inch in thickness to a total depth of two feet. This type of auger has been used with satisfactory results by the Nebraska Agricultural Experiment Station in securing samples of soil for chemical analysis and soil moisture studies. The auger is also well adapted for use in making determinations of the apparent specific gravity of soils under field conditions, since a definite volume of soil may be removed without the neces- sity of digging around a tube and cutting the soil off even with the lower edge. In use the auxiliary tube is driven into the soil to such a depth that when the auger blade is just resting on the surface of the soil, the adjustable gage may be set in the first notch on the auger stem, and at the same time rest on. the top of the tube. The gage is then raised CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 453 No. 12356. No. 12362. Nos. 12370-2. No. 12360. No. 1878. to the next notch and the auger turned until the gage again conies in contact with the top of the tube, or, in other words, has removed one inch of soil, since the notches are one inch apart. In this manner, a sample of soil from each inch may be obtained to a depth of 2 feet. Complete with auxiliary tube .' 9.00 12356. SOIL AUGER, Pugh's. According to Dupont specifications this anger is especially designed for use in hard ground, and is the best tool on the market for penetrating the hard pan. It is hand-made out of special steel, and actual tests made in all parts of the world have proved that one Pugh will outwear and outbore a dozen or more of any other make. Useful for soil sampling, tree planting, ditching, drainage and other earth boring where deep holes are re- quired, or where the ground is hard. With extensions it can be lengthened so as to reach to any desired depth; it is used very extensively for prospecting or for well boring, as well ac for agricultural work. Length, 4% feet; weight, 10 to 12 pounds; bit, 1% inches in diam- eter: complete with handle 18 to 21 inehhes long $5.10 12357. EXTENSION for No. 12356 Soil Auger. Length, 3 feet 1.00 12360. FOOT PLATE, for use with any Soil Auger 2 inches or less in diameter to prevent the crumb- ling away of the soil around the edge of the hole. Consists of a steel tube slightly over 2 inches in diameter provided at the upper end with a steel plate about 4.5x10 inches. The tube is driven into the ground before the sampling hole is started and the Plate makes a convenient rest for the feet during the entire operation of removing samples 2.50 12362. CARRYING CASE, for Auger Field Set, substantially made of hard black fiber with lock and clasps, and handle for carrying. Compartments are provided for holding one No. 12346 Auger (or one No. 12350 Auger), one No. 12348. Auger, two handles for the above, four No. 12351 Extensions, and a wrench for the lock nuts. Complete with Wrench, but without Augers or Extensions 7.50 12:JG4. AUGER FIELD SET, consisting of No. 12362 Carrying Case with wrench, one No. 12346 Auger, one No. 12348 Auger, and four Xo. 12351 Extensions 27.00 12366. AUGER FIELD SET, same as Xo. 12364, but with No. 12350 Auger instead of No. 12346. 27.00 12370. SOIL SAMPLING TUBE, King's. Tube of brass, 5 feet long, graduated every 6 inches. Cut- ting head of steel with area of opening one-ten millionth of an acre. Steel collar at top to receive blows of hammer shown in illustration. This hammer is of east iron, weighing 8 pounds, and is of suitable shape to be held easily in the hand. To obtain soil samples the tube is driven into the ground to the desired depth by means of the hammer. A column of soil is thus forced up into the tube from which it is jarred after re- moval from the ground. The outside of the cutter being larger than the tube allows it to be drawn from the ground more easily. If, however, the tube is not withdrawn from the ground with sumcient readiness, No. 12374 Tube Hoist should be used. With Hammer 8.00 12372. SOIL SAMPLING TUBE, King's, same as No. 12370, but 3 feet long. With hammer. . . 7.00 1878. SAMPLING TUBE BRUSH, for cleaning Nos. 12370 and 12372 Soil Sampling Tubes. Bristle brush, with strong wire handle. Total length, 65 inches .25 454 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 12376. 12378. No. 12388. No. 12376. 12374. SOIL SAMPLING TUBE HOIST. This contrivance will fill the need for some device for remov- ing Soil Sampling Tubes from the ground. Movement is imparted upward on the handle and, the leverage being ample, no great effort is needed to remove tubes from the most solid soils. Hoist only, without Sampling Tube $8.00 SOIL SAMPLING TUBE, Whitney's, especially useful for obtaining samples for determination of moisture content and nitrifying power of soils; a brass tube 9 inches long, sharpened at one end and with a mark 6 inches from that end, provided with rubber caps for closing each end air tight '. 70 SOIL SAMPLER, Bacteriologist's, after specifications by H. A. Noyes of the Purdue University Agricultural Experiment Station. This sampler is a brass cylinder 11 inches long by 2 inches in diameter, with an especially constructed cutting edge. The end having the cutting edge is furnished with a tight fitting brass cap 2 inches in height. When the upper end is plugged with absorbent cotton, the sampler is ready for sterilization. The sampler is easy to sterilize, easily kept clean, easy to use, and durable, and hence will be found valuable in bac- teriological work. This apparatus will (1) sample accurately soil subjected to any system of management; (2) not interfere with the field conditions existing where the sample is taken, thus making future samples comparable; (3) give a representative sample of soil; and (4) keep the sample practically under field conditions until analyzed, since the tube itself acts as container for the sample. Graduated as shown in the illustration, and with directions for use 2.50 DRIVING HEAD, of cast iron, for use with No. 12378 Soil Sampler 40 SAMPLING CLOTH, 18x18 inches, for receiving soil samples from Soil Samplers. Impervious to moisture * per dozen 1.00 12386. SAMPLE CARRYING OUTFIT. The inconvenience of cumbersome fruit jars and soil bags is done away with in the design illustrated. A neatly finished carrying case, with door and handle, holding one dozen seamless tin cans of one pint capacity, with tight-fitting lids. (See . No. 1828.) The suitability of these cans for drying pans makes this an economical outfit, since special pans for the drying oven are not needed. Complete with one dozen cans. . . 4.50 1828. SOIL SAMPLE CANS, Seamless Tin, same style as used in No. 12386. Capacity, ounces % 1 2 4 8 16 24 Per dozen 25 .30 .50 .70 1.00 1.60 1.80 For other SOIL SAMPLE CANS AND BOXES, see Boxes. SOIL SAMPLE JARS, see Jars. SOIL SCOOPS, see general heading Scoops. 12388. SHAKER, Chest of Drawers Design, for preparing soils for mechanical analysis. Essentially as described in Bulletin 84 of the Bureau of Soils, but with hinge mounting similar to that described under No. 12060 Shaker. The gearing is of the enclosed type and is arranged to be belted to any % h. p. motor having V-groove pulley. The chest is substantially made of hardwood nicely finished, and has six drawers each with eight compartments for holding No. 12391 Sterilizing Bottles. Complete on a massive hardwood base with forty-eight No. 12391 Sterilizing Bottles, but without motor 78.50 For MOTORS for use with No. 12388, see general heading Electrical Instruments. 12379 12382, CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 455 No. 12391. No. 12394. No. 12400. 12390. SHAKER, Tray Design, for preparing soils for mechanical analysis. Two trays with compart- ments for eight bottles each are mounted on a wooden platform attached to a substantial wooden base by four hinged metal supports. The shaking movement is imparted through a worm gear mounted on the same base. Sufficient power will be furnished by a % h. p. "motor. The trays are both made removable for convenience in handling and filling. Com- plete with, sixteen bottles, but without motor $53.50 12391. BOTTLES, Sterilizer, for use in Nos. 12388 and 12390. Capacity, 8 oz per dozen .90 SHAKER, Soil Sieve, see No. 12148. 12394. SHRINKAGE APPARATUS for determining the shrinkage of soils, as described in Hosier and Gustaf son's "Soil Physics Laboratory Manual," and used at the University of Illinois. This is a tray of brass, 3 inches square at the top, with beveled sides to facilitate removal of the soil sample. In use, a piece of cheese cloth is placed on the bottom of the tray, which is then filled with moist soil. The soil block is then removed from the tray and allowed to dry. The shrinkage in area may readily be determined by measurement 45.00 SIEVES for Soil Analysis, see general beading Sieves. SOIL CONTENT TESTERS 12400. CONDUCTIVITY BRIDGE, for determining the soluble salt content of soils; made after designs approved by the TJ. S. Bureau of Soils. The use of this bridge depends on the fact that the electric current is conducted by the salt in solution and that the conductance of the solution or, conversely, its resistance to the pas- sage of the current, is determined largely by -its concentration. The magnitude of current that will pass is increased by an increase of salt in solution; or the resistance to the pas- sage of the current decreases with the increase of salt. The instrument is of general util- ity in measuring the resistances of solutions of soils. It is designed primarily for use as a field instrument, and finds its greatest use in determinations of "alkali" or harmful excess of soluble salts, frequently present in the soils of arid and semiarid areas. In survey work it gives a convenient method for determining in the field the percentage of alkali in a soil, so that the mapping may be carried on concurrently. It is also useful in determining the salt content of irrigation and seepage waters. The instrument, by means of which resistances are measured, is a modified form of slide-wire Wheatstone 'a bridge. In operating the bridge, the cup is filled with the soil saturated with water, and placed in the clips provided for it. The resistance of the cup contents is then read, and from the resistance the amount of soluble salt present determined by reference to the tables given in the Bulletin mentioned above. (See Bulletin 6, U. S. Bureau of Soils.) Complete as described $150.00 Note. — Bridges of the above type made by us have proved satisfactory to and met the require- ments of the U. S. Bureau of Soils, Washington, D. C. Bridges of this type are used by the Atchison, Topeka & Santa Fe Railway Company for testing the alkali content of their tank water. 12401. DRT BATTERY, complete, as used in No. 12400 Conductivity Bridge 1.25 456 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 12404. No. 12420. No. F2333. 12404. SOIL ACIDITY TESTER, Truog. This apparatus is made after specifications by E. Truog of the University of Wisconsin. The principle employed is an entirely new one and indicates clearly not only the presence of soil acidity but the degree of the acidity. Consists of a specially designed Alcohol Heater together with a Graduated Boiling Flask, Brass Measuring Cup, Brass Measuring Spoon, Spatula, and all necessary reagents. The test is completed in from 10 to 15 minutes, and the presence of acidity is shown by discoloration of the white test paper used, and the degree of acidity by the exact color assumed by the paper as com- pared with a chart of standard colors furnished. A full set of directions giving exact de- scription of the test with all precautions is included. Complete as described, in a neat hard- wood carrying case $7.50 Parts for No. 12404. 12405. FLASK, 300 cc capacity, with mark at 100 cc 75 12406. MEASURING CUP for soil 20 12407. MEASURING SPOON for reagents 15 12408. TEST PAPER, 50 sheets in glass vial per vial .15 12409. SET OF REAGENTS, sufficient for making 50 tests, consisting of a bottle containing 55 grams of a mixture of calcium chloride anfl zinc sulphide specially prepared, vial of test paper (50 strips), and measuring spoon 75 F2333. SPECIFIC HEAT APPARATUS (modified design after Prof. A. G. McCall) for determining the Specific Heat of Soils; may also be used for determining the specific heat of any substance. Consists of a double-walled heater or steam jacket with large rectangular base and support rod, and a double-walled calorimeter. Both heater and calorimeter are of very substantial construction, and are well insulated. The heating chamber extends through the heater and is closed at both ends with heavy insulated covering. The top cover has two openings, one for a thermometer, and the other for suspending the sample to be tested. The clamp which holds the heater rests on a collar which is clamped to the support rod, so that when the sam- ple has come to a constant temperature the lower cover of the heater can be swung back out of the way and the heater rapidly swung around to a position over the calorimeter. The transfer of the specimen from heater to calorimeter can thus be readily and quickly effected. Heater and calorimeter complete as described, but without thermometers 30.00 F2334. CALORIMETER only of No. F2333 without thermometers 10.00 12420. TANK for holding water, of galvanized iron, 12 inches in diameter, with drop handles, for use with all soil tubes 14 inches long, or under (e. g., No. 12492) 1.90 12422. TANK for holding water, of galvanized iron, 12 inches in diameter. For use with soil tubes 3fi inches long, or under; made especially for No. 12444 Tube 3.50 12424. TANK for holding water, of galvanized iron, 26x6x6 inches. For use in all capillarity experi- ments. Used with Tubes Nos. 12444-12464 1.80 CEXTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 457 No. 12444. No. 12448. No. 12454. No. 12445. No. 12434, 12430. TENACITY OF SOILS APPARATUS, for determining the tenacity of moist soils. In this new and improved design, which has been daveloped from the original in use at the University of Illinois, the inaccuracies due to friction, caused particularly by a collection of dirt on the moving parts of the- instrument, have been completely obviated, and constant conditions thereby assured. Two brass soil containers are supported on a hinged frame which in turn is securely clamped to the table top. The soil containers are removable from the frame and are so constructed that they may be immediately replaced in exactly the same relative posi- tion. In use, the containers are'held firmly together by means of the metal stirrup shown in the illustration; the moist soil is compacted in the containers and smoothed level with the top, thus leaving one square inch section for testing. Weights are now placed in the hanger suf- ficient to pull the soil apart. Complete, as illustrated, with canvas hanger, but without weights $12.00 THERMOMETERS, Soil, see general heading Thermometers. 12434. TRAY, Color, for testing effects of color of soils on temperature. Waterproofed wooden tray, 6 ft. x 3 ft. x 6 inches deep, with drainage 15-00 12436. TRAYS, Drainage, for showing effects of drainage on temperature of soils. Two water-proofed wooden travs, each 3 ft. x 4 ft. x 6 inches deep, one made water tight, the other provided with drainage Per set 25.00 12438. TRAY, Puddling, for mixing and working soils. Water tight, waterproofed wooden tray, 2 inches x 25 inches x 2% inches. ' Will not warp 3.50 TUBES, SOIL, ALL KINDS 12444. TUBE, Capillarity, McCall. with side tubes for studying the distribution of moisture in vertical columns of soil; also for determining the lateral movement of capillary moisture. Of brass, 36 inches long by 2 inches in diameter, with perforated bottom and small lateral tubes at definite intervals 3.75 12445. TUBE, Sampling, for use in obtaining samples from the side openings of No. 12444 Capillarity Tube as suggested by Prof. John A. Slipher of Purdue University. A brass tube with diam- eter slightly contracted at the sharpened end is provided with a plunger by which the sample of soil may be ejected 90 12448. TUBE, Capillarity, McCall, for determining the rate of the capillary rise of water in soils. Of brass, 36 inches long by 2 inches in diameter, with perforated bottom. Running lengthwise of the tube is a slot fitted with a window of thin celluloid through which the moisture height may be noted. The construction of this tube is such that an additional length, which the illustration shows in place, may readily be attached. Without additional length 4.50 12450. TUBE, Extension, with coupling for studying rise of moisture to greater height than is possi- ble with Xo. 12448 alone. Of brass, 36 "inches long. With coupling 5.00 12451. CELLULOID STRIP, 36x3 inches, for either Xo. 12448 or Xo. 12450 60 12454. TUBES, Capillarity, of celluloid protected by wire gauze. These tubes consist of a cylinder of galvanized iron wire gauze 2 inches in diameter, surrounding a cylinder of thin transparent celluloid formed of a strip of celluloid sufficiently wide to go 1% times around the tube. These tubes are soil tight, transparent, and durable, and are very satisfactory for studying the distribution of water in capillary *ise experiments, since the inner tube may be with- drawn and unrolled, exposing the soil for easy sampling. Length, inches ." 12 24 36 48 Each . 66 1.00 1.50 2.80 458 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 12465. No. 2818. No. 12472. I J I n No. 12464. CB No. 12458 No. 12462. 12455. 12458. 12459. 12462. VI -1 til. 12465. 2818. 12468. 12472. P3355 CELLULOID STRIPS for No. 12454 Tubes. Length, inches 12 24 36 48 Each $0.18 .38 .54 .96 For CLEANING BRUSH, see No. 1876. For SUPPORT, see No. 12462. TUBES, Capillarity, Sectional, for determining capillary rise of water in soils. These sections are made of heavy brass tubing and are 8 inches long by 1% inches in diameter. Each sec- tion is threaded at both ends to receive brass couplings so that the tubes may be built up to any desired length. The tubes may readily be cleaned, and the breaking of the soil column which causes so much annoyance in long brass and glass tubes is obviated, because the sec- tion joints, which are tight enough to prevent evaporation losses from the soil, are loose enough to permit equalization of air pressure inside and outside of tube. (For Bottom Tube, see No. 12459 below.) Per section (with one coupling) 1.25 BOTTOM TUBE, for No. 12458 with perforated bottom. For use as lowest tube of set. . 1.50 CAPILLARITY TUBE SUPPORT for supporting 2-inch tubes 32 inches long or longer in a vertical position. Will hold six tubes which may be readily removed or put in place. The base is constructed in form of a tray and holds a water-tight zinc tank. A rod and ring at the side of the tray is designed to hold an inverted flask so that the height of the water in the tray may be kept constant. Complete as illustrated, but without flask or tubes.. 9.00 TUBES, Capillarity, Glass. Diameter, inches 2 2 2 1 Length, inches 8 15 24 60 Each 70 1.20 1.30 .80 PERFORATED BOTTOM for 2-inch Glass Soil Tubes. May be used with tubes from Ii»/i6 inches to 2^g inches in diameter. Clamps firmly to the bottom of the tube, but may readily be removed for changing from one tube to another 30 For CLEANING BRUSH, see No. 1876. CAPILLARITY TUBES, Glass, student's lamp chimney form per dozen 1.80 SUPPORT, of wood, x-or holding four No. 2818 Capillarity Tubes 1.40 SUPPORT, for four No. 2818 Capillarity Tubes, more substantial than No. 12468. Base of wood with metal uprights and adjustable shelf for supporting tubes; finely finished 2.50 TUMBLERS, for use with No. 2818 Tubes; ^-pint size per dozen .60 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 459 No. 8386. Nos. 12500-6. No. 12479. Nos. 12487-8. No. 1876. 12476. 12478. 12479. 12484. 124S6. 12487. 12488. 8386. 12492. 12494. 12496. 1876. 12500. For ORGANIC MATTEB, TUBES, see Xo. 12464. TUBE, Percolation of Air, for comparing the rate of the flow through soils. Made of brass, 18 inches long by 2 inches in diameter, with outlet tube near bottom $2.00 TUBE, Percolation of Water, for determining the rate of percolation of water through soils. Of brass, 18 inches long by 2 inches in diameter, with lateral inlets and drainage tube, and with solid bottom below and perforated bottom above drainage tube 2.00 SUPPORT BLOCK, for use with Xo. 12478 Percolation Tube. This block is necessary when several soils are to be compared 1.75 For CLEANING BRUSH, see Xo. 1876. TUBE, Specific Gravity, for determining the apparent specific gravity of surface soils under field conditions. Of steel, 12 inches long by 3 inches outside diameter, with cutting edge 2.75 TUBE, Specific Gravity, same as Xo. 12484, but 4 inches inside diameter 5.00 DRIVING HEAD, of cast iron, for use with Xo. 12484 Specific Gravity Tube to prevent bat tering the upper edge when the tube is driven into the ground 50 DRIVING HEAD, same as Xo. 12487, but for use with Xo. 12486 Tube 1.50 MAUL for driving Xo. 12484 Specific Gravity Tube. Substantially made of iron with hardwood faces. The handle is two feet long, and the Maul is sufficiently heavy for its purpose, with- out being clumsy net 1.40 TUBE, Volume Weight, for determining volume weight and pore space. Of brass, 12 inches long by 2 inches in dameter, with solid bottom, and crease one inch from the top 1.25 TUBE. Volume Weight, for elementary work, of brass, 1^x3% inches 40 TUBE, Water Holding Capacity, brass, 12 inches long by 2 inches in diameter, with perforated bottom, !*>? mm perforations, and crease one inch from top 1.25 TUBE BRUSH, for cleaning soil tubes of 2 inch diameter; has a wooden handle 3 feet long and is provided with a tuft of bristles at the end for reaching the bottom corners of the tube .60 TUBES, Soil, so constructed that one style of tube may be used for all experiments. They are made from brass tubing 10 inches long and 2 inches in diameter. A cast brass base, which is corrugated on its upper surface, is soldered into the bottom of the tube. On the lower sur- face of this casting is a connection for rubber tubing. A brass disk with circular perfora- tions, and somewhat smaller than the inside of the soil tube, is dropped to the bottom of the tube and rests on the corrugated surface of the brass base, allowing free passage of air or water through the tube. The tubes are so constructed that they can be connected in series bv means of rubber tubing so that a constant water level may be obtained in all the tubes. ' Each 1.50 460 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 12512. No. 12538. No. 12540. No. 12552. 12502. TUBE BACK for 6 No. 12500 Soil Tubes. The tube rack consists of a cast iron base, smoothly finished and japanned, to which is attached an upright standard. On this standard are car- ried two castings, the lower one being arranged to take and hold the lower ends of the soil tubes by means of lugs on its upper surface, and the upper consisting of a series of rings to support the upper ends of the soil tubes in a concentric position. This arrangement holds the tubes securely, but still allows them to be removed or replaced very easily. At the same timo it is compact, the rack and tubes occupying less than one square foot of desk room $2.00 (For illustration, see page 459.) 12506. SUPPLY TANK, used in determining the comparative rate of flow of water through various soils. This tank is made of polished brass and rests on the top of the standard of the tube rack by means of a socket in its base. Two short brass tubes extend downward from the base of the tank in such a position as to fall within the two soil tubes on opposite sides of the rack. The six soil tubes having been connected in series, the water flows from the tank to the soil tubes, maintaining a constant water level therein 3.50 (For illustration, see page 459.) 12508. SOIL TUBE AUGER for removing wet soil from tubes. This auger is 1% inches in diameter, of twist pattern and made from polished cast steel. Will clean tubes to the bottom 2.50 12512. WATER RETENTION CUP, for determining the maximum water retained by soil. Of brass 2 inches in diameter by % inch high, with diaphragm of perforated metal fastened about %6 inch below top. This cup is used in studying the wilting point by means of the direct relationship which exists between the maximum water retained by any soil and the wilting point. (See Hilgard's "Soils," page 209) 30 1253U. SOLDER, Bar Form, half lead and half tin. Approximate weight, iy» Ibs Per bar 1.50 12532. SOLDER, Wire Form, half lead and half tin Per pound 1.00 12534. SOLDER, Wire Form, with resin center; half lead and half tin. Used for all electrical joints and splices where danger of corrosion must be eliminated. No flux required when using this solder. In 1-pound packages Per package 1.25 12538. SOLDERING COPPER, % lb., with handle 60 12540. SOLDERING COPPERS, Electric, for either A. C. or D. C. circuits. Tip interchangeable and can be replaced instantly. With cord and plug. In ordering please state exact voltage. No " A B Length, inches 10 14% Weight, ounces 9 18 Diameter of tip, inches % % Watts 60 150 Each 7.50 9.50 12544. SOLDERING COPPER, Jewelers', 1 ounce, high grade, for instrument use 25 12548. SOLDERING PASTE, easy to apply, non-acid, fumeless, non-corrosive. Especially useful for electrical work and in out-of-the-way places. In metal cans. No A B Size, ounces 8 Each 35 .85 12552. SOLDERING OUTFIT, consisting of a soldering iron, bar of solder, scraper and flux, in a neat wood box .60 12554. SOLDERING OUTFIT, less elaborate than No. 12552, consisting of soldering iron, piece of wire solder, and flux .25 SOLDERING IRON HEATER, SOP Burners Nos. 2114-6. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 461 No. 12564. No. 12568. No. 12572. No. 12573. No. 12574. No. 12576. No. 12578. No. 12580. No. 12582. 12564. 12568. 12572. • 12573. 12574. 12576. 12578. 12580. 12582. 12588. No. 12588. SPATULA, Glass, 6 inch blade ground on both sides. Width of blade, % inches ........ $0.25 SPATULAS, Horn, double, with spatula on each end. Length, mm ............................................... 100 125 150 200 .12 .15 .25 275 .85 310 1.10 195 .55 4 30 8 .95 345 1.30 212 .72 6 .40 10 1.50 Each ...................................................... 10 SPATULAS, Platinum, see Platinum Ware. SPATULAS, Porcelain, -with paddle at one end, knob at the other, glazed throughout. Length, mm Each SPATULAS, Porcelain, double, with spatula at each end. Length, mm ............................... 105 120 150 Each ...................................... 25 .35 .42 SPATULAS, Hard Rubber, solid, with flexible blade. Length, inches ................................................. Each SPATULAS. Steel, Flexible, with cocoa wood handle. Length of blade, inches ............. 3456 Each ............................... 36 .40 .45 .60 SPATULAS, Steel, Very Flexible, with narrow point for weighing, and wood handle. Length of blade, inches ................................................... 4 Each ..................................................................... 60 SPATULA, Steel, with special 4 inch blade, very stiff. Widely used in baking and milling labor- atories for gluten mixing ........................................ .............. .90 SPATULAS, Solid Steel, Flexible, with balanced handle, nickel-plated. Length of blade, inches .................................. 3 4 o 6 Each ................................................... 60 .70 .75 .85 SPECIFIC GRAVITY APPARATUS, soe Bottles, Specific Gravity; Hydrometers; also Xos. 392, 1734, 2500 and 11048. SPECIMEN MOUNTS, Riker's, suitable for mounting insects, butterflies, fungi, shells, etc., or thick bulbs or plants too large for thp"Botanical Mounts, No. 1556. Size, inches ............................. 2#>x3 4x5 5x6 e^-xS1/^ 8x12 12x16 Each .................................... 15 .20 .25 " .30 .50 1.00 Per dozen ............................... 1.75 2.30 2.80 3.50 6.00 12.00 442 2.65 225 .85 8 .50 12 2.30 5 .80 462 CENTBAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 12736. No. 12748. 12692. SPEED COUNTER or REVOLUTION COUNTER, suitable for any purpose requiring a small, light and accurate counter. Registers up to 99,999. Its action is very smooth and uniform and it will stand a very high rate of speed. If run backwards, it counts backwards. Illustra- tion is full size. Nickel-plated $1.50 12694. SPEED COUNTER or REVOLUTION COUNTER, with ball thrust bearing and spring clutch which allows the spindle to turn freely until the second hand of one's watch has come to zero; a slight pressure on the end of the instrument starts the count; when pressure is released the count stops. Registers 9,999, and can be used on either high speed or low speed machinery. One pointed and one flat rubber tip furnished which serve as insulators when taking the speed of electric machinery. The flat tip can also be used on flat or pointed shafts. Nickel-plated. 4.00 12698. SPEED INDICATOR, improved form, may be run at highest speed required without heating; dial plate has two rows of figures reading right or left; rubber tips for both pointed and cen- tered shafts, which not only remove the jar and run smoothly, but produce a stronger fric- tional contact with the shaft. The rotating disc, being carried by friction, may be moved to the starting point where the raised knobs coincide. Pressing the raised knob on the rotating disc with the thumb prevents the disc from moving until the hand of the watch gets to the right position to take the time. Every hundred revolutions may be noted by feeling the knob pass under the thumb, thus relieving the eye which has only to look on the watch to note the time. Nickel-plated 1.26 See also DE LAY STOP-WATCH AND REVOLUTION COUNTER No. 12968. 12714. 12718. 12722. 12730. 12731. 12734. SPINTHARISCOPE, see Radioactivity Apparatus. SPLINTS, 100 in package per package SPONGES, for cleaning purposes, 16 to a pound per pound SPOON, Aluminum, table size, handle with ribbed center SPOONS, Deflagrating, see Deflagrating Spoons. SPOON, Glass, lamp blown, teaspoon SPOON, Glass, lamp blown, tablespoon SPOONS, Horn, plain form. Length, mm 100 .11 150 .18 Each 12736. SPOONS, Horn, with spatula end. Length, mm Each SPOONS, Platinum, see Platinum Ware. SPOONS, Porcelain, with spatula end. Length, mm 96 Each 21 SPOON.^Sodium, of brass gauze, with cover and wooden handle SPOON, Sodium, Capsule, with ram-rod, according to Brownlee SPOONS, Sodium, cartridge shells, 8x13 mm inside Per dozen 12742. 120 .2V 140 .38 160 .50 100 .20 200 .75 150 .22 247 .85 12744, 12746 12748 .10 2.00 .20 .30 .40 200 .25 200 .30 490 2.75 .30 .25 .10 CENTRAL SCIENTIFIC CO., CHICAGO, TT. 8. A. 463 No. 12796. SPRAYING MATERIAL, see Catalog A of Agricultural Apparatus. SPRING BALANCES, see Balances. 12754. SPRINKLER, Rubber, bulb of extra quality, 8 ounce size, with straight neck $1.00 12756. SPRINKLER, Rubber, same as No. 12754, but with bent neck 1.00 SPROUTING APPARATUS, see Grain Testing Apparatus. SPUTUM BOTTLES, Square, see No. 2757. 12760. SPUTUM DISH, according to Webster, consisting of a 100 mm Petri dish with one half black- ened .50 12766. SQUARE, all steel, nicely polished, length 2 feet, width 2 inches, face marked in 4ths, 8ths, and 16ths of inches, back in 4ths and 12ths of inches, with board and brace measure. . 1.60 12768. SQUARE, Combination. The equivalent of a set of try squares, a depth gage, a level, a mitre, and, with the auxiliary center head, a centering square, both inside and outside. Convenient for transferring exact measurements, laying out work, or to square in a mortise. Twelve inch blade graduated on one side in % mm and 32nds of inches; on the other in millimeters and 64ths of inches. Complete, with center head and level 3.00 12772. SQUARES, Try, blued steel blade graduated in 8ths of inches, and rosewood handle. Size, inches 6 9 Each 60 .70 STAGES, Mechanical, see Microscope Accessories. STAGES, Warm, see Microscope Accessories. 12780. STAINING APPARATUS, Corper-DeKhotinsky, see aext page. STAINING DISHES, see Dishes, Staining. STAINING JARS, see Jars, Staining. 12790. STENCIL, Cenco, transparent, for quickly and easily drawing assembled apparatus in student note books _JQ 12794. STENCIL FIGURES. Each figure has a beaded lock on its edge so' that the figures can be joined together, permitting the use of combinations of figures at one time instead of single figures. Complete set of one-inch numbers from 0-9, dollar mark, cent mark, beginner ender and period gQ 12796. STENCIL LETTERS. Same style as No. 12794. Complete set' of one-inch 'letters from 'A to & with beginner and ender, period, apostrophe, comma and blank 1.25 CENTRAL SCIENTIFIC CO., CHICAGO, TT. S. A. No. 12784. (Patent Pending.) STAINING APPARATUS, Corper-DeKhotinsky, Electrically Heated, as used at the Municipal Tuberculosis Sanitarium of Chicago, a clean and neat device for hot staining and fixing. By its use it is possible to fix smears of sputum, etc., without danger of burning, to stain them without danger of boiling the carbolfuchsin solution and also to avoid drop- ping carbolfuchsin over the laboratory tables and floors. It consists of an asbestos wood frame with base which will stand red heat without destruction. In the bottom is a sliding metal shelf, to be filled with sand for catching any drippings and to aid in reflecting all the heat upward front the heating units, of which there is one for every two sides. These units, which are easily replaceable, are wound with nichrome wire, which is insoluble in boil- ing carbolfuchsin. The slide carriers are nickel-plated brass frames made to fit in the asbes- tos frame at a suitable height above the electrical units. The base is provided with leveling screws. A set of fuses is placed on the apparatus, so that there is no danger from accidental short circuit. The apparatus is made in two sizes, as listed below, and is intended for stand- ard 3x1 inch slides. It consists of heating box, slide carrier, tray, cross test level and five feet of asbestos covered cord and two plugs. Complete with rheostat for close regulation of heat. No A B For slides 10 20 12780. For 110 volts $40.00 50.00 12781. For 220 volts 41.00 51.00 12782. SLIDE CARRIERS, extra, for Nos. 12780 and 12781. No A B For slides 10 20 Each 3.25 4.00 12784. STAINING APPARATUS, Corper-DeKhotinsky, Electrically Heated and Regulated (Patent Pending), constructed for the same purpose as No. 12780, with the addition of the DeKhotinsky Automatic Thermo-Regulating System to facilitate maintaining a constant temperature, which is especially convenient in research work. In addition to its use in fixing and staining, it may be used as a hot plate for evaporating, concentrating, drying and boiling, etc. It is very economical in consumption of electrical energy, requiring only 180 watts to maintain a tem- perature of 180°C., over 82 square inches of surface of aluminum plate. For 20 slides. No A B C D A.C. D.O. For volts 110 220 110 220 Each 92.50 95.00 90.00 92.50 12785. SLIDE CARRIER, extra; for No. 12784 5.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 465 No. 12802. Nos. 12810-11. STERILIZERS, ALL KINDS STERILIZERS. Autoclaves, see Autoclaves. 12800. STEEILIZEE, Instrument, Electrically Heated, with three heats. Made of heavy copper, nickel- plated and double tin lined with perforated tray. Provided with automatic cut-out which cuts off the current if the sterilizer should run dry. The hinged lid is provided with a ven- tilator which prevents dripping when opening the instrument. Operates on either A.C. or D.C. Current consumption on low heat, 125 watts; on high heat, 500 watts. Size, 10x4%x2% inches deep. Complete with five feet of attachment cord, connector, and lamp socket plug $24.00 12802. STEETLIZEB, Instrument, Lewis Form, with lifting tray, for sterilizing small instruments in pathological and bacteriological laboratories. The tray carrying the instruments is raised clear of the hot water by opening the lid, and is held there until the lid is closed. Made of copper nickel-plated. Dimensions, 10x5x3 inches deep; total height closed, 6 inches. Com- plete with burner and base as illustrated 21.00 STERILIZER, Combination Instrument and Dressing, with control valve, for sterilizing instru- ments and dressings. Consists of a double walled chamber resting on a removable base which is used to contain water for generating steam. The steam passes between the double walls and after the contents of the inner chamber have become heated to 212°F., the live steam is admitted by a control valve at the top and forced through the contents and out at the bottom of the other end. VThen sterilization is completed, the steam is again cut off and the contents are left in the chamber until thoroughly dried. The base can be used separately with the cover and one rack as an instrument sterilizer. Complete with two wire cloth racks and valve opening for thermometer. No A Length, inches 14 Width, inches 6 Depth, inches 6 Made of heavy tin, copper bottom 9.50 Made of polished copper, tin lined 19.50 STERILIZEK, Combination Instrument and Dressing, Electrically Heated, of polished copper, tin lined, same as No. 12807, but with Prometheus electric heater mounted in the base. Can be attached to any lamp socket. Complete with three-heat plugs, attachment cord and plug. No ...'. A B Length, inches 14 18 12810. For 110 volts 38.00 12811. For 220 volts 38.00 53.50 12806. 12807. B 18 7% 8 12.00 26.00 466 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Nos. 12816-17. Nos. 12820-21. 12816. 12817. 12820. 12821. 12822. 12823. Nos. 12822-23. STERILIZERS, Hot Air, DeKhotinsky Electrically Heated and Regulated, Triple Wall, con- structed to secure uniformity of temperature throughout heated chamber and dependable temperature regulation. Provided with the DeKhotinsky standard system of heating, bi- metallic thermo-regulator for temperatures up to 160°C., and with inner glass door for obser- vation of contents. Complete with five feet of cord, Hubbell receptacle and separable Hub- bell plug for attachment to any lamp socket. No A B C Inside dimensions, inches 105/8x7x6% 14%xlL'xll% 19%xl7xl4 Shelf space, square inches 91 282 476 For 110 volts A.C. and D.C $55.00 90.00 145.00 For 220 volts A.C. and D.C 57.50 92.50 147.50 For full description of construction, heating and ventilating system and temperature control, see No. 9830 Drying Ovens. For EXTRA FUSES for Nos. 12816-7, see No. 9838. STERILIZERS, Hot Air, DeKhotinsky Electrically Heated and Regulated, Single Wall, de- signed to supply the need for a moderate priced sterilizer with dependable temperature con- trol and uniform temperature throughout. With same system of heating and temperature control as No. 12816, but of simpler construction. For full description, see No. 9846 Drying Ovens. Width, Depth, Height, Vol. Inside, Shelf Space, Voltage Inches Inches Inches Cu. Inches Sq. Inches A.C. & D.C. Price 11 10 12 1320 220 110 40.00 11 10 12 1320 220 220 42.50 STERILIZERS, Hot Air, DeKhotinsky Electrically Heated and Regulated, Single Wall, of same construction as No. 12820, but larger, with two doors and with twelve 115 watt heating units. With same equipment as No. 12820. Width, Depth, Height, Vol. Inside Shelf Space, Voltage Inches Inches Inches Cu. Inches Sq. Inches A.C. & D.C. Price 18 12 14 3024 430 110 60.00 18 12 14 3024 430 220 62.50 For EXTRA FUSES for Nos. 12820-3, see No. 9850. For EXTRA HEATING UNITS for Nos. 12816-23, see Nos. 7526-7. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 467 No. 12826. No. 12828. No. 12830. 1282t'>. STERILIZERS. Hot Air, Double Wall, of sheet iron, with enclosed base, asbestos mat, and perforated shelves. Without burner. No A B Height inside, inches 9 10 Width inside, inches 9 12 Depth inside, inches 6 10 Height over all, inches 19% 21% Number of shelves 1 2 Each $13.00 21.50 Tor BURNERS for use with No. 12826, see Nos. 2108 and 2220. 1282S. STERILIZERS, Hot Air, Low Form, for gas only, double walled, made of sheet iron covered with asbestos. The instrument is heated by a row of small Bunsen burners around the sides of the base, insuring an even circulation of heat. The air is introduced through openings in the sides. With two shelves, ventilator in top and tubulations for thermometer and gas regu- lator. Without thermometer or gas regulator. No A B Height inside, inches 12 18 Width inside, inches 24 24 Depth inside, inches 12 14 Each 45.00 67.00 12830. STERILIZER, Hot Air, High Form, similar in construction to No. 12828, but tall and narrow in shape. Height inside, 19 inches; width inside, 12 inches; depth inside, 9% inches. With three perforated shelves 33.00 468 CENTRAL SCIENTIFIC CO., CHICAGO, IT. 8. A. Nos. 12834-6. Nos. 12840-2. 12834. 12835. 12836. STERILIZERS, Hot Air, Lautenschlaeger Form, of Russia iron, covered with asbestos. This sterilizer has three walls, providing two air spaces through which currents of air, heated (when provided with burners for gas) by a row of small Bunsen burners between the outer walls, pass continuously. An even temperature is thereby maintained. They can be heated to 150°C., in about 5 minutes. Without thermo-regulator or thermometer. No A B C D Height inside, inches 12 18 24 30 Width inside, inches 18 24 30 36 Depth inside, inches 9 14 18 20 Number of shelves 1 2 3 3 With gas heater $ 48.00 62.00 108.00 150.00 With oil heater 90.00 123.00 190.00 247.50 With electric heater 122.50 165.00 275.00 330.00 STERILIZERS, Hot Air, Lautenschlaeger Form, same as No. 12834, but mounted on stand 24 inches high. No A B Height inside, inches 24 30 Width inside, inches 30 36 Depth inside, inches 18 20 Number of shelves 3 3 12840. With gas heater 121.00 158.50 12841. With oil heater 203.00 261.00 12842. With electric heater 288.00 345.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 469 12846. 12847. Nos. 12846-7. No. 12854. STERILIZERS, Arnold Steam, with side door and two removable perforated disks. These steril- izers are well known for their compactness and economy. They maintain the unvarying tem- perature of boiling water in all parts of the sterilizing chamber. No A B C D Height, inches 7% 10% 11% 12% Diameter, inches 8% 9 10% 10% Made of heavy tin, copper bottom $6.25 7.25 8.75 9.75 Made of copper 14.50 20.00 23.00 24.75 12850. STERILIZERS. Arnold Steam, Boston Board of Health Pattern. Made of copper throughout with double walls and doors, and with two removable wire cloth trays. No A B Height inside, inches 14% 15% Width inside, inches 8% 12% Depth inside, inches 9 12% Each 55.00 60.00 12854. STERILIZER, Test Tube, Electric, consisting of a small cylindrical drum, 2%x3*£ inches, hav- ing a nickel-plated metal body with a top and bottom of %-inch transite, mounted upon three legs. Near the center is a metal cylinder li^6 inches in diameter and 1% inches in dep^h, surrounded by a resistance coil which heats its entire surface uniformly and quickly. The heating unit "is controlled by an automatic electro thenno-regulator, contained within the drum, adjusted by means of a screw reached by a small screw driver. The thermo-regulator completely controls the temperature so that the contents of the test tube may be brought to the boiling point without boiling over. Metal rings are provided for the receptacle, permit- ting the use of %, %, % and 1-inch test tubes. Complete including test tube and small cru- cible, as illustrated 15.00 12855. STERILIZER ATTACHMENT, for use with No. 12854, for sterilizing hypodermic syringes. needles, etc. Constructed of metal, nicely finished and polished, arranged to fit into the heating tube of No. 12854. Dimensions of the sterilizer are: diameter, 3% inches; depth, % inch. The wire basket can be removed by means of an adjustable wire tongs, which fits into loops shown on wire basket. Similar loops are attached to the body of the sterilizer so that the entire apparatus may be easily removed from heated receptacle (the loops on sterilizers are not shown in cut.) A nest of four test tubes is furnished with the sterilizer, the largest one (1 inch in diameter) having a cork disk in the bottom to protect the point of scalpel. This outfit in connection with No. 12854 makes an ideal small sterilizer for hvpodermic syringes and needles, as well as catheters, probes, scalpels, etc. Complete as illustrated 7.50 470 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 12882. No. 6156. C No. 12868. D E STIRRING APPARATUS B 10 % 5 Me 6.50 C 12 1% 8 Via 7.00 12864. STIRRERS, High Speed Turbine, for use in water baths, etc., where rapid stirring must be maintained. They are compact and efficient, operating without noise or violent disturbance of the water. Especially adapted for use in thermostats, in physical chemistry laboratories No A Length, inches 8 Diameter, inches % Capacity, liters per minute 5 Power required to operate, h. p Me Each $6.00 STIRRING APPARATUS, consisting of a three step cone pulley with chuck for holding glass stirring rods, mounted in bracket with rod for attachment to support stand. Diameter of largest pulley, 3% inches. For rods up to *,4 inch 4.00 STIRRING RODS, of glass for use with No. 12866. Style A B C D E Each 80 .80 1.25 1.00 .80 STIRRING APPARATUS, Blair's, as used in iron analysis. Complete with stirrers, asbestos plate, 6 beakers and covers, without motor 20.00 STIRRING APPARATUS, Electric, with adjustable bracket, spindle with chuck to hold stirring rods, and three step pulley. Diameter of largest pulley, 3% inches. A rheostat is provided 12866. 12868. 12872. 5156. for controlling the speed. For rods up to }4 inch. No. A B C D A.C. D.C. For volts ............................................. 110 220 110 220 Each ................................................ 27.50 31.50 27.50 31.50 STIRRING RODS, see Glass Rods. STILLS, see Distilling Apparatus. STOP-COCKS, ALL KINDS to % inch rubber 12880. STOP-COCKS, Brass, for gas, nickel-plated, with long taper hose end for tubing; male thread for attaching to gas pipe coupling. Not for water. Diameter of gas pipe inside, inches .............................. ^4 % l/2 Size of I. P. thread, inches ..................................... J/4 % % Each .......................................................... 40 .50 .60 12882. STOP-COCKS, Brass, for gas, same as No. 12880, but with female thread for attaching to gas pipe. Diameter of gas pipe inside, inches .............................. % % % Size of I. P. thread, inches ..................................... Vt % % Each . ............................ 40 .50 .60 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. 471 No. 12890. No. 12891. No. 12908. No. 12912. 12885. 12886. 12884. STOP-COCK, Brass, for gas, single, nickel-plated. Especially suited for laboratory use. The nipple is 2% inches long, tapering from % inch diameter at the valve to *4 inch diameter at the end. The serrations prevent rubber tubing from slipping off. With % inch iron pipe male thread ?0.60 STOP-COCK, Brass, two-way, consisting of two No. 12884 Single Stop-Cocks, with flange. 2.50 STOP-COCK, Brass, four-way, consisting of four No. 12884 Single Stop-Cocks, with flange. 4.00 STOP-COCKS AND NIPPLES FOR AIR PUMPS. The following nipples and stop-cocks are accurately made of brass, polished and lacquered, and in order that they may be capable of the greatest service in the laboratory we have not threaded them for use with iron pipe fittings, but have used the same threads as are used on all our Air Pump Plates and Air Pump Accessories (v^g-inch in diameter and 16 threads to the inch). Stop-cocks are ^ inch bore; nipples, %6 inch bore. 12890. NIPPLE, of brass, female screw 12891. NIPPLE, of brass, male screw STOP-COCK, double male screw STOP-COCK, one end for tubing, the other with male screw STOP-COCK, both ends for tubing STOP-COCK, one male and one female screw STOP-COCK, one end for tubing, the other with female screw STOP-COCK, both ends with female screws 12892. 12893. 12894. 12895. 12896. 12897. 12900. .40 .40 .60 .60 .60 .80 .80 1.00 STOPCOCK, Brass, for No. 6720 Gas Bags. One end for attaching rubber tubing, the other a %x21/£-inch brass tube for nozzle of gas bag .90 12908. STOP-COCKS, Glass, straight. Bore, mm 1 2 3 4 5 Each 1.25 1.38 1.75 2.00 2.25 12910. STOP-COCKS, Glass, same as No. 12908, with curved outlet for aspirator bottles, etc. Bore, mm 1 2 3 4 5 Each 1.50 1.65 2.00 2.25 2.50 12912. STOP-COCKS, Glass, same as No. 12908, but with capillary tubes for use in gas analysis appara- tus, etc. Outside diameter of tube, 6 to 7 mm. Bore of stopper, mm ; 1 3 Each 1.40 1.50 472 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 12938. No. 12940. 12916. STOP-COCKS, Glass, three-way lamp blown form. Bore of stopper, mm Each . No. 12942. 1 4 2.75 $1.80 2.00 12918. STOP-COCK, Glass, same as No. 12916, but with capillary tubes. Bore of stopper, 2 mm 2.25 12920. STOP-COCK, Glass, four- way. Bore of stopper, 2 mm 2.50 12922. STOP-COCKS, Glass, three-way, with downward outlet through stop-cock plug. Bore of stopper, mm 1 Each 2.65 12924. STOP-COCKS, Glass, three-way, same as No. 12922, but with capillary tubes. Bore of stopper, mm Each . 1 3.00 o 2.75 o 3.15 12928. 12930. STOP-COCK, Glass, two-way, with plug bored at an angle. Bore of stopper, 2 mm 1.75 STOP-COCK, Glass, two-way, same as No. 12928, but with capillary tubes. Bore of stopper, 2 mm 2.15 12932. STOP-COCKS, Glass, three-way, with plug with two holes bored at an angle, and with two out- lets on one side. Bore of stopper, mm 2 4 Each 2.50 4.40 12934. STOP-COCKS, Glass, three-way, same as No. 12932, but with capillary tubes. Bore of stopper, 2 mm 3.00 12938. STOP-COCKS, Glass, two-way, with mercury seal, and plug bored at an angle. Bore of stopper, mm Each 2 4.00 12940. STOP-COCKS, Glass, Burette, with outlet drawn to a tip, for attaching to burettes. Bore of stopper, mm 1 Each 1.40 12942. 12946. 4 5.50 2 1.50 STOP-COCK, Glass, Presenius form, for burette tips. With inlet tube bore, 5 mm; outlet bore, 2 mm 1.20 STOP-COCK GREASE, for lubricating and preventing leakage. Heavier and more resistant to reagents than vaseline per ounce bottle .25 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 473 No. 12954. No. 12962. No. 12956. STOP-WATCHES FOR TIMING A SINGLE PERFORMANCE. 12954. STOP-WATCH, Ordinary Design. Xickeled case, stem wind, lever escapement, % second divi- sions. Convenient for testing and experimental work, being non-magnetic $11.00 12956. STOP-WATCH, Decimal Design. The minute is divided into 100 parts so that the watch is very useful in all timing operations in which the minute is the unit of time. Readable to % of a division, L e., 1/300 minute. Otherwise same as No. 12954 described above 11.00 FOR TIMING TWO EVENTS WHICH START SIMULTANEOUSLY BUT END AT DIFFERENT TIMES. 12960. STOP-WATCH. Xickeled case, stem wind, lever escapement, % second divisions, non-magnetic, provided with two hands for timing two events which start simultaneously but end at different times. Useful in timing laboratory operations, and in timing first and second places in a race. Has a higher grade movement than Xo. 12954 25.00 FOR TIMING AN INTERRUPTED PERFORMANCE. 12962. STOP-WATCH. Xickeled ease, stem wind, lever escapement, 7 jewels, % second divisions, non- magnetic. This watch is operated by moving a "side piece" instead of pushing the "crown." This method is easier on the mechanism, giving the watch much longer life. It also operates more smoothly than the old style and will record the time of an interrupted performance, giving exactly the time used for the performance itself, excluding the interruption. The hands will come back to their original starting point only by pushing the "crown" 12.50 12966. STOP-WATCH, DeLay, Electrically Operated. A high grade American made stop-watch, with an electromagnet attachment by means of which the starting and stopping of the watch may be accomplished. The watch is a seven jewel movement in a nickeled case. A chronometer with stop-watch attach- ment is used, as this type of stop-watch is more rugged and reliable. The chronometer is a good time keeper and the electromagnet attachment does not in any way interfere with the use of the watch as a time keeper or as an ordinary stop-watch. This device is very useful in many laboratory experiments, such as the accurate determination of the velocity of moving bodies and the timing of various operations by automatically opening and closing the electric circuit. 474 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Nos. 12966-8. STOP-WATCH, DeLay, continued. The speed of rotating shafts can be determined by using this stop-watch in connection with a special revolution counter (see No. 12968 below). Great accuracy is obtained because of the fact that both the revolution counter and stop-watch are started and stopped simultaneously and are in positive connection through an electric circuit. A small flash light battery gives sufficient power for operating this stop-watch $20.00 12968. STOP-WATCH and REVOLUTION COUNTER, DeLay. An accurate and reliable revolution counting device. This device consists of No. 12966 Electrically Operated Stop-wateh and a special revolution counter, connected together in such a manner that the time taken to make any number of revolutions may be accurately determined. The starting and stopping of the watch is simultaneous with the starting and stopping of the speed counter. No error can pos- sibly enter in. This device is easily more accurate than any other speed counter on the market. The revolution counter is the best worm gear counter made and is equipped with a small special attachment for this work. This attachment does not interfere with the use of the counter in the ordinary manner, and it can be used for either direction of rotation. A battery of the pocket flash-light type is used to operate the device. To use the device, the circuit is first closed, which places the watch under electrical control. The stem is then pressed, which releases the hand mechanically. Placing the rubber tip of the counter in the shaft center opens the watch circuit and starts the long second hand. The stop-watch continues to run until the speed counter is removed from the shaft, when the elec- tric circuit is again closed, stopping the second hand. Pressing the stem of the watch holds the hand mechanically so that the electric circuit may be opened. After the reading of both instruments has been taken, the indicators may be returned to zero and it is then ready for the next reading. The revolutions may be taken for any number of seconds or the time for any number of revolutions accurately determined. When great accuracy is desired a curve may be plotted from which accurate readings may be taken for fractions of a second. Watch and Revolution Counter complete 30.00 12969. REVOLUTION COUNTER only, of No. 12968, with battery and cords. STORAGE TANKS, see Jars. STOVES, see Burners. 12974. STRAIGHT EDGE, cherry, one edge beveled; 24-inch For T-SQUARES, see general heading Drawing Instruments. STREAK PLATES, see Arsenic Plates. STROPS. Razor, see Microtome Accessories. SUBERITE RINGS, see Cork Rings. 10.00 .35 CENTRAL SCIENTIFIC CO., CHICAGO, U. & A. 475 No. 12982. No. 12988. No. 13002. No. 10486. No. 10510. SUGAR ANALYSIS APPARATUS No. 13010. BEAKERS, Copper, see general heading Beakers. BEAKERS, Glass, see general headings, Beakers. 12982. BEAKER, Digestion, for determining sncrose in beeta by the Herzfeld modification of the Sachs Le Docte method. Made of nickel-plated copper 14 em high, 6 cm in body diameter, and 4 cm in diameter at the top. Complete with selected cork stopper covered with tin foiL (See Journal of the Association of Official Agricultural Chemists, VoL n, No. 1, Part n, page 81) **-°0 CRUCIBLE. Alundum Filtering, see general heading Crucibles. CRUCIBLE HOLDERS, see Nos. 3446 and 3448. CRUCIBLES, Gooch. Opaque Fused Silica, see general heading Crucibles. DISHES, Lead, Bottle Caps, see general heading Dishes. FLASKS, Volumetric Sugar, see general heading Flasks. 12988. FLASK, Spencer Inversion, for use in inverting sugar for polarization, with three marks divid- ing the total 100 ce capacity into 75, 5 and 20 cc divisions 1.25 FUNNELS, Sugar, see general heading Funnels. 13002. HORTVET TUBE, for determining the lead number of maple products, etc., for use in a cen- trifuge. Length of tube, 15.2 cm; diameter of wide part, 3 cm; diameter of neck, 2 em; stem graduated to 5 ec in Vio cc divisions, with 5 cc line 5 mm below beginning of wide part. With etched spot to facilitate numbering 80 HYDROMETERS, Brix, see general heading Hydrometers. MUFFLE FURNACE, see general heading Furnaces. OVEN, Vacuum, see general heading Ovens. 10486 PIPETTE, Spencer's Glucose, capacity 50 cc, graduated from 5° to 20° Brix in 1/5° divisions 2.00 10510. PIPETTE, Sucrose, capacity 52.096 ec, graduated from 5° to 25" Brix in 1/10° divisions. . 2^0 PLATINUM SUGAR DISHES, see general heading Platinum Ware. POLARISCOPES, see general heading Polariscopes. PYCNOMETERS, see Bottles, Specific Gravity. REFRACTOMETERS, see general heading Refractometers. ROEHRIG TUBES, -.-e general heading Extraction Apparatus. WEIGHING DISH and COUNTERPOISE, see general heading Balances. WEIGHTS, Normal Sugar, see general heading Balances. SULPHUR DETERMINATION APPARATUS 13010. SULPHUR APPARATUS Dudley's Improved, for the determination of sulphur in iron by the bromine method. Mounted on iron support as illustrated 15.00 13011. SULPHUR APPARATUS, Dudley's, glass parts only of No. 13010 12.00 476 CENTRAL SCIENTIFIC CO., CHICAGO, U-. S. A. No. 13028. No. 5732. No. 13032. 13014. SULPHUR APPARATUS, Meyer's, for the determination of sulphur in iron and steel by the bromine method. No A B Number of bulbs 6 10 Each $1-50 2.00 13016. SULPHUR APPARATUS, Meyer's, same as No. 13014, but with stop-cock ground to fit bulb. No A B Number of bulbs 6 10 Each r 4.00 4.50 13020. SULPHUR APPARATUS, for the determination of sulphur in oils, consisting. of three glass parts with wooden base i 3.00 13024. SULPHUR APPARATUS, Norris, for the determination of sulphur in iron and steel. Complete as illustrated 3.50 3141. SULPHUR BULB only of No. 13024 70 SULPHUR PHOTOMETER, Parr's, see No. 2378. 13028. SULPHUR RACK, Illinois Steel Company Form, consisting of an iron stand with a row of high temperature burners with individual stop-cocks, and with adjustable flask supports and clamps. A rack is provided with hooks to support sulphur bulbs. Without glassware 35.00 5732. SULPHUR APPARATUS, for determining whether grain has been bleached, as recommended in Circular No. Ill of the United States Bureau of Plant Industry. Consists of an Erlenmeyer flask with ground in connecting tube. Capacity, 500 cc 1.95 SULPHUR APPARATUS, Pennock and Martin, see general heading Crucibles. 13032. SUNSHINE RECORDER. This instrument records the duration and intensity of sunshine for twenty-four hours on a specially prepared photographic chart, which merely requires washing in cold water to become permanent. The chart being divided into hours, an exact record ia thus obtained with the minimum of trouble. Complete with divided arc for adjustment of in- strument to any latitude, with 100 charts and directions for use 25.00 13033. EXTRA CHARTS for No. 13032.. . .Per 100 3.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 477 No. 13036. No. 13050. No. 13038. NO. 13054. SUPPORTS, ALL KINDS 13036. SUPPORTS, Iron, rectangular base, with coppered steel rod. No A B C D Size of base, inches 4x6% 5x8 5%x9 6x11 Length of rod, inches , 18 20 24 36 Diameter of rod, inches 'Ho % % % Each $0.45 .60 .80 1.70 13038. SUPPORTS, Iron, tripod base, with coppered steel rod. No A B C D Length of leg, inches 4»4 5¥> 6Vj 7% Length of rod, inches 18 20 24 36 Diameter of rod, inches %o % % % Each 50 .65 .90 1.75 13040. SUPPORTS, Iron, rectangular base, consisting of Support No. 13036, with Rings No. 11502. 13042. 13044. 13048. 13050. 13051. 13054 No A B C Xumber of rings 2 4 Diameter of rings outside, inches 3.4 3,4.5 3.4.0.6 Each 85 1.25 1.65 SUPPORTS, Iron, tripod base, consisting of Support No. 13038 with Rings No. 11502. No A B C Number of rings 2 4 Diameter of rings outside, inches. 3.4 3,4.5 1.35 D 4 3.4.5,7 2.40 D 4 Each .90 3,4.5.6 3,4,5,7 1.80 2.50 SUPPORT, Iron, tripod base, consisting of Xo. 13038B, with one each Extension Rings No. 11504, 3, 4 and 5 inches, and 3 Xo. 2914 Clamp Holders. Complete as illustrated 2.20 SUPPORT, Hardwood, Gay-Lussac's, with elnmp cork lined, adjustable in three directions. Length of upright rod, 16 inches 1-40 SUPPORT, Hardwood. Improved form of Gay-Lussac 's, with clamp on a %-ineh extension rod, 10 inches long 1-50 WOODEN CLAMP only of No. 13050, for use with clamp holders, etc., in connection with iron supports .80 SUPPORT, Hardwood, Schellbach's. Clamp cork lined, universal movement 1.70 478 CENTRAL SCIENTIFIC CO., CHICAGO, TI. S. A. No. 13060. No. 13064. No. 13072. No. 2248. No. 10286. No. 13076. No. 5292. No. 13094 (in use). 13058. SUPPORT, Burette, hardwood, with cork-lined clamp, for one burette. Length of rod. 16 inches u . $0.90 13060. SUPPORT, Burette, hardwood, same as No. 13058, but for two burettes 1.25 13064. SUPPORT, Burette, Hardwood, round base, with nickel-plated steel rod, 22x%6 inches, and re- volving spring clamps for four burettes. Adjustable in height 4.50 13072. SUPPORT, Burette, hardwood, Chaddock's, improved form. The rod and base are of polished hardwood. On top of the base is a rectangular piece of white glass. The clamp is of spring brass, which holds the burette firmly in place without danger of breakage. The burette is readily placed in position or removed by simply pushing back the brass spring. For two bu- rettes 3.00 13076. SUPPORT, Burette, Iron, consisting of Support No. 13036B, with Clamp No. 2842 1.00 13078. SUPPORT, Burette, Iron, consisting of Support No. 13038B, with cork-lined hardwood clamp for two burettes 2.50 2248. SUPPORTS, Burner, Iron, with flat top and heavy screw for attachment to support stand. Use- ful for supporting burners and many other laboratory devices. No A B Diameter, inches 3% 5 Each 25 .60 10286. SUPPORT, Conductivity, for use in thermostats for holding flasks, calomel electrodes, etc. Heavy base of white metal with rod and clamp of brass, nickel-plated 2.75 SUPPORTS, Electrolytic, see Electrolytic Apparatus. 5292. SUPPORT, Fermentation Tube, copper, for 10 tubes, without foot, as No. 5280 1.60 13094. SUPPORT, Funnel, hardwood, for one funnel, with arm large enough to accommodate beakers. Height of rod, 16 inches 80 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 479 No. 13106. No. 13110. No. 13122. 13096. SUPPORT, runnel, hardwood, for two funnels $0.75 13098. SUPPORT, Funnel, hardwood, similar to No. 13096, but for four funnels, and with holes slotted enabling funnels to be removed from the side 80 13100. SUPPORT, Funnel, hardwood, with iron clamp for attachment to support stand. With slotted holes for four funnels. Without support stand .45 13102. SUPPORTS, Funnel, hardwood, improved form, with slotted holes. Adjustable in height from 7% to 12 inches. No A B For funnels 6 12 Each 4.00 8.00 13106. SUPPORT, Funnel, hardwood, Leach, for separatory funnels. Both bars adjustable in height. For six funnels 7.00 13110. SUPPORT, Funnel, Stoddard's Aluminum, with set screw for use with No. 13113 Bas? and Rod. For four 2 inch funnels 1.20 13112. SUPPORT, Funnel, Stoddard's Aluminum, same as No. 13110, but for four 2% inch funnels 2.00 13113. BASE AND ROD, for use with No. 13110 and 13112. Heavily weighted. Length of rod, 16 inches; diameter of rod, *4 inch; diameter of base, 3% inches .65 SUPPORTS, Pipette, see No. 10560. 13122. SUPPORT TABLES, hardwood, with leaded base, adjustable in height. No A B Diameter of top, inches 4 4 Height closed, inches 8% 10 Height open, inches 13% 15 Each 1.50 1.50 480 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. No. 13134A. No. 13124. No. 13130. No. 13134B. No. 13140. No. 13138. No. 13146. 13124. SUPPORT TABLES, hardwood top with iron tripod, and brass tube, adjustable in height. The heaviness of the base and support rods make this an unusually stable support for heavy appa- ratus or for apparatus which should be supported free from vibration. All surfaces are turned true on the lathe, insuring a horizontal surface. No A B Diameter of top, inches 6 8 Height closed, inches 12 16 Height extended, inches 18 26 Each $4.00 6.00 C 12 17 27 7.00 Dimen- 13126. SUPPORT TABLES, same as No. 13124, but with top of iron machined to a true plane, sions same as No. 13124. No A B C Each 4.25 7.00 8.00 13130. SUPPORTS, Test Tube, copper, round, for use in water baths. Widely used in incubation and inactivation work. For tubes up to % inch diameter. No A B C Diameter, inches 5 6 8 Number of holes 14 Each 1.00 13134. SUPPORTS, Test Tube, hardwood, with heavy base and drying pins. No For tubes Each . 24 1.25 A 6 .30 36 1.50 B 10 .40 13136. SUPPORT, Test Tube, hardwood, Griffith's, similar to No. 13134, but with trough in base for draining, or for holding stirring rod, pipettes, etc. With 10 holes for % inch tubes, 2 for 1 .65 inch tubes and 12 drying pins 13138. SUPPORTS, Test Tube, hardwood, for twelve tubes in two rows. No Diameter of holes, inches Each t 13140. SUPPORT, Test Tube, hardwood, for 12 tubes in two rows with 12 drying pins. holes, lYs inches 13144. SUPPORTS, Test Tube, hardwood, with two shelves, and drying pins. No A For test tubes 13 Each . 40 .45 .70 Diameter of .80 B 25 .70 13146. SUPPOBff, Test Tube, hardwood, without glued joints, shipped knocked down, with directions for putting together; for 16 tubes, with 8 drying pins .60 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 481 No. 13172. No. 13174. 13150. SUPPORTS, Test Tube, hardwood, with pins onlv, for drying test tubes, bottles, flasks, etc. No A B For test tubes 25 50 Each $0.90 1.10 13154. SUPPORTS, Test Tube, stamped stael, finished with hard baked black enamel. No A B For test tubes 14 18 Holes for % inch tubes 9 Holes for 1 inch tubes 9 Drving pins 7 9 Each 40 .60 13158. SUPPORT, Test Tube, tinned iron wire. Will hold 40 tubes. Size, 9% inches long by 4Vj inches wide by 3!£ inches high $1.10 13160. SUPPORT, Test Tube, tinned iron wire, round form, for forty-four % inch test tubes. Diameter, 7% inches; height, 3% inches 1.10 13162. SUPPORT, Test Tube, tinned iron wire, square form, for forty-eight % inch test tubes. Dimen- sions, 7% inches by 7% inches by Z% inches high 1.10 131G4. SUPPORT, Test Tube Basket, tinned iron wire, cylindrical form, for sterilizing and incubating culture tubes. Diameter, 6 inches: height, 6 'inches 80 13166. SUPPORTS, Test Tube Basket, tinned iron wire, rectangular form. No A B Height, inches 6 5% Width, inches 6 4 Length, inches 6 5 Each 1.00 .90 13168. SUPPORT, Test Tube Basket, tinned iron wire, rectangular form, with partition in the middle. Length, 8% inches; width, 5 inches; height, 5% inches 1.30 13172. SUPPORT, Test Tube, Vaccine, nickel-plated brass, for 18 vaccine tubes. For use in DeKho- tinsky Wassennann Bath No. 14332 '. 5.00 13174. SUPPORT, Test Tube, Wassennann, nickel-plated brass, with holes for 48 tubes 3x% inches. For use in DoKhotinsky Wassermann Bath No. 14332 4.50 SUPPORT, Weighing Tube, see Balance Accessories. 482 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 13190. SURVEYING INSTRUMENTS, SIMPLE TYPE For Forestry, Mining1 and Geological Work. BAROMETERS, see general heading Barometers. 13182. CLINOMETER, Abney's Reflecting Level or Pocket Altimeter, for measuring the height of buildings, trees, hills, etc., and also for fixing the slopes for railroads, the rise and fall of ground for drainage purposes, and all operations where angular distance or inclination of surface is desired. Sighting tube 5 inches long, large German silver arc, extra long draw eye-piece, improved fixing clamp to vernier. The arc has two graduated scales upon it, one giving the angular measurements by degrees, and subdivided to 5 minutes by the vernier divisions on the index. The other scale is figured 1 to 10 with their subdivisions. Com- plete in leather case, with directions $13.50 F2625. COMPASS, Sight, watch case form, 50 mm diameter, with raised dial and full circle divisions. Bar needle, 30 mm long, with agate cap. Sights and spring cover 11.50 13190. COMPASS, Surveying, Brunton Patented Pocket Transit, for surface and underground survey- ing in mining and geological work. Case is of aluminum 2%x2%xl inch. Weight, 8 ounces 25.00 13202. LEVEL, Hand, Reflecting, for measuring slopes and gentle elevations, bronzed tube with level, cross-hair, and fixed eye-piece; length, 5 ounces Consists of a square inches; weight, 2% 4.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 483 Ko. 13208. No. 13216. 13206. LEVEL, Simple Tonn, consisting of a metal level, a pair of level sights and a stand for sup- porting the level upon a flat surface or on the end of a stake or crow bar. By its use one can readily determine levels from a given point to one at a distance, such as locating or setting the profiles for foundation work, ascertaining the proper grades for drains, ditches, etc. All parts of the stand are of metal, nickel-plated. The level is of metal, nickel-plated and japanned, and provided with a 3% inch horizontal spirit level and two 1^ inch vertical spirit levels. The sights are adjustable and clamp to the top of the level by set screws. One sight is provided with a peep hole and the other with a horizontal cross wire. Com- plete as described, without stake or support $4.50 13208. LEVEL, Bostrom's Improved, provided with telescope which has a magnifying power of eight diameters which enables the cross on the target to be read at a distance of one-quarter of a mile in any direction. A circle graduated in degrees is provided for obtaining angles, squar- ing up buildings, and all such work. Included in the outfit is a sliding target rod, graduated in feet, inches, and quarter inches, telescoping to five feet when closed and to nine and one- half feet when extended, and having a sliding target of the usual form with thtfmb-screw for securing in any position. The metal parts are of iron and brass, and the wood parts, in- cluding the target, are of pine. Complete in neat wood box with tripod, sliding target rod. target and plumb bob 18.00 13210. LEVEL, Bostrom's Improved, similar to No. 13208, but more substantial and of finer finish. The telescope has a magnifying power of twelve diameters so that the instrument has a much greater range. All wood parts are of hardwood and all metal parts of brass except the tar- get. Complete in neat wood box with tripod, sliding target rod, target and plumb bob 30.00 13216. QUADRANT, for measuring altitudes. A sector 6 inches in diameter, graduated from 0°-90° in single degree divisions, mounted on polished wood base, with indicator and sight attach- ment. A level is mounted on the base so that it may be adjusted to a true horizontal posi- tion ... 2.50 484 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 13226. Nos. 13242-3. 13220. 13224. SURVEYORS' ARROWS, made of %4 inch round steel fourteen inches long, and with rings enameled in bright vermilion per set of eleven $1.25 TAPES, Surveyors' Chain. Heavy ^4 inch steel tape; nicely finished hardwood reel, with metal folding handle and two large and strong detachable rings. Trimmings nicely nickel- plated. Graduated in feet, with end feet in tenths; or in links, with end links in tenths, graduations etched on. Length feet 100 200 300 links 100 200 300 Each 8.00 12.50 17.50 7.00 10.00 12.50 13226. TAPES, Surveyors' Chain, graduated on Babbitt Metal. This tape will answer the require- ments of the most severe usage and take the place of the old-time steel chain. It is made of practically unbreakable steel, heavily coated with white metal to prevent rusting and cor- rosion, and somewhat heavier than the ordinary chain tape. The graduations are stamped into Babbitt Metal at each foot (end feet in tenths), or at each link (end links in tenths), so that the graduations can readily be felt as the tape is allowed to pass through the hand. Each tape is provided with a pair of detachable handles, and the reel, which is built especially for such tapes, has a nickel-plated frame with folding winding handles, is easily wound and of beautiful finish. Length feet 100 200 300 links 100 200 300 Each 7.70 14.00 18.00 7.50 11.00 14.00 TRANSIT, Pocket, see No. 13190. 13232. SWIMMING CUPS, Porcelain, with perforations, for washing specimens. With cork stopper which floats the cup in the washing fluid. No Diameter, mm Height, mm Each SYRINGES, ALL KINDS SYRINGES, Hypodermic, Luer, all glass, entirely aseptic, without packing, threads or washers. Easily sterilized. With slip-on needles. Capacity, cc 1 Graduated in, cc ^oo Syringe only, without needles 1.75 Syringe in pasteboard box, with two steel needles 2.25 Syringe in nickel-plated case, with two steel needles 3.00 13240. 13241. 13242. 13243. 1.25 1.50 2.25 2.75 10 3.00 3.50 A 27 35 .50 20 1 4.00 4.50 B 35 50 .65 30 1 5.00 6.00 Syringe in nickel-plated case, with two platinum-iridium needles ............ 4.75 2.15 4.15 3.90 9.00 4.50 6.25 10.00 13.50 7.75 15.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 485 j^j _. . ••-.^EjS f ' - ^ - - - ^-» - - - .. ^ .— .-5 | -v- - - - - - -T> I _ ' ^ , f°T subcutaneous injections. i f°r subcutaneous injections. F 22 G 22 H 20 J 20 2.25 2.25 2.25 2.25 K 18 2 3.00 No. 13260. " No. 13264. 13246. SYRINGES, Hypodermic. Luer Assortment, consisting of 16 assorted needles for bacteriological and serological work together with one each of the following syringes, in metal case: Luer Syringe, % cc, graduated in I4otn> for gray oil. Luer Syringe, 1 cc, graduated in }iootn> ^or tuberculin. Luer Syringe, double scale, 25 minims and 1% cc in Luer Syringe, double scale, 30 minims and 2 cc in Luer Syringe, 5 cc, graduated in ^th, for antitoxins. Luer Syringe, 10 cc, graduated in %th, for antitoxins and salvarsan, Luer Syringe, 20 cc, graduated in }£th, for antitoxins and salvarsan. This outfit contains all of the syringes required for investigation or practical work in bacte- riology or serology ................................................................ $27.00 13248. NEEDLES, Hypodermic, steel, slip-on type, for Luer Syringes. No ................... A B C D E Gage ................ 26 26 24 24 24 Length, inches ....... % % % 1 1% Per dozen ............ 1.50 1.50 1.50 1.50 2.00 Note: — Other needles not regularly carried in stock will be furnished upon short notice. 13254. SYRINGES, Hypodermic, Sub-Q Safety, with plunger of black glass, provided with prongs to prevent the asbestos packing from loosening. The 6 ce and larger sizes are supplied with ring handle and with rubber coupling for needle. Complete with two polished steel needles in cardboard case. Capacity, cc 1 24 6 12 20 50 100 Graduated to, ce ............ #00 ^0 tf0 i{<» % % J£ % Each ...................... 1.50 1.00 1.50 1.75 2.00 2.50 5.00 7.50 13256. STEEL NEEDLES, for No. 13254, with threaded hub. For syringe, capacity, ee ..... 1 24 6 12 20 50 100 Gage " ...................... 25 25 22 22 21 18 18 18 Length, inches .............. % % 1 1 1% 1% 1% 1% Per dozen ................... 1.50 1.50 2.25 225 2.25 2.50 2.50 2.50 Per gross ................... 15.00 15.00 22.50 22.50 22.50 25.00 25.00 25.00 Note: — Other needles not regularly carried in stock will be furnished upon short notice. 13260. SYRINGE, Aspirating, with piston graduated to 14 dram, glass barrel with nickel-plated metal trimmings, finger rings, 3 aspirator needles (1 each 15 gage 3 inch, 17 gage 2% inch and 19 gage 1% inch), one 3 inch trocar and canula, and nickel-plated stop-cock. Capacity, 2 drams. Complete in nickel-plated case ............................................. 4.50 13264. SYRINGE, Injecting, of brass, nickel-plated; capacity, 45 ce. For use in injecting reagents and masses into different blood vessels. With two-way stop-cock, four straight canulae of different calibers, and two T canulae for injecting in both directions. Ends of canulae are grooved to prevent them from slipping out of vessels, and projections run out from base of canulae to fasten threads to. Complete as described, in wooden case with six eanulae and stop-cock 9.00 486 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. See Note on Nos. 13318-20. No. 13320. 13266. SYRINGE, Injecting, Kitchen's Form, for injecting precise amounts. The mixtures are made in the syringe barrel and enough sterile salt solution is placed in the side arm to wash in the entire dose. By this means the necessity for removing the bulb of the syringe during injec- tion is dispensed with, and accuracy of dosage is insured. Made of resistance glass which can be readily sterilized. Complete with rubber bulb, rubber connection, and antitoxin needle. (For full description see Kolmer's Infection Immunity and Specific Therapy, page 233) . . $1.50 13267. GLASS BARREL only of No. 13266 60 13268. NEEDLES only of No. 13266 per dozen 3.00 13300. TACHOMETER,, Hand, with three scales, rendering it unnecessary to change gears. The instru- ment is mounted in a case of aluminum, black enameled and nicely finished, with nickel-plated ring, and is provided with three dials, reading 75 to 500 r. p. m., 150 to 1000 r. p. m., and 750 to 5000 r. p. m. Diameter of dial, 3 inches; length over all, 5 inches; total weight with- out case, 2 pounds. Complete with triangular steel tip, rubber tip, rubber muff, extension rod, and center punch in leather carrying case with handle 75.00 TALLY, Hand, see Counter No. 3318'. 13306. TAPE, Transparent Adhesive, for mending pages of books, drawings, papers, maps, etc., % inch wide; 4 yards on spool with metal holder per spool .06 1536. TAPE, Gummed Cloth, heavy mending tape for strengthening books, pamphlets, maps, etc., % inch wide. A 10 yard roll in special box with slot for drawing out as needed. . . .per roll .20 TAPE, Insulating, see No. 5136. 13310. TAPES, MEASURING, Linen, English. Patent leather case, waterproof coated, with brass fold- ing handle and trimmings. Tape % inch wide, graduated in *4 inches. Length, feet 40 100 Each $1.20 2.25 13312. TAPES, MEASURING, Linen, Metric. Brass bound case and folding handle. Tape 13 mm wide, graduated in centimeters. Length, meters 10 25 Each 65 1.35 13314. TAPES, MEASURING, Linen, English and Metric. Nickel-plated brass case with spring wind and center stop. Tape % inch wide, graduated in millimeters and % inches. Length, meters 1 Each 60 .90 13318. TAPES, MEASURING, Metallic, English and Surveyors. Hard leather case, folding handle, nickel-plated trimmings. Tape % inch wide, made of best woven linen with metallic warp, graduated on one side in tenths of feet and on the other side in links. Length, feet 50 100 Each 4.50 7.50 13320. TAPES, MEASURING, Steel, English. Metal lined hard leather case, nickel-plated trimmings, folding winding handle opened by pressing pin on opposite side. Tape % inch wide, gradu- ated in feet, tenths, and hundredths. Length, feet 50 100 Each 5.60 9.50 NOTE: Nos. 13318-20 Measuring Tapes are provided with a new marking by means of which instantaneous readings of both feet and inches can be made without the necessity of referring back to the last entire foot. The method is well shown in the accompanying illustration. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 437 _ No. 13324. No. 13326. No. 13332. No. No. No. No. No. No. 13346. 13360. 13352.13354.13358.13360. 13324. TAPES, MEASURING, Steel, English and Metric, German silver case with spring wind and stop. Tape Vi inch wide (5 meter, ^6 inch), graduated in millimeters and 16ths of inches. Length, meters 1 2 5 Each $1.00 1.50 4.50 13326. TAPE, Steel, Diameter Measuring, giving directly the diameter of a circular object when its circumference is measured. In metal lined, hard leather case with nickel-plated trimmings, with folding flush handle opened by pressing upon a pin on opposite side. The tape is of steel % inch in width and 50 feet long, graduated on one side in feet, tenths, and hundredths, and on the other side in diameters (inches and tenths of inches). Fitted with a special peg or spike for fastening to tree or other object to be measured 7.00 TAPERS, Wax, see Wax Tapers. TAR TESTER, see Asphalt and Tar Testing Apparatus. 13332. TEST GLASSES, conical form, with lip, for sedimentation. Capacity, cc 30 60 125 175 250 Each..' - .50 .50 .60 .80 .90 TEST PAPER, see Paper. TEST TUBES, ALL KINDS 13346. TEST TUBES, Thin Wall, ordinary glass, with lip, well annealed, free from lead, for chemical use. Xo A B C D E F G H J Length, inches 345566678 Diameter, inches.... %%%%%% 1% 1 Per dozen 17 .20 .22 .24 .25 .27 .40 .45 .55 Per gross 1.65 1.85 2.10 2.20 2.40 2.60 3.90 4.40 5.40 13350. TEST TUBES, Thin Wall, ordinary glass, with lip, on foot. No A B C D Length, inches 4 6 8 Diameter, inches % % % 1 Each 07 .12 .15 .26 Per dozen 65 1.20 1.50 2.60 13352. TEST TUBES, Thin Wall, ordinary glass, with lip, with side arm. Xo A B C Length, inches 5 6 8 Diameter, inches % % 1 Each 13 .15 .18 Per dozen 1.30 1.50 1.80 13354. TEST TUBES, Thin Wall, ordinary glass, with lip, graduated. Capacity, cc 5 10 20 25 Graduated to, cc Mo Mo % % Each . .25 .30 .42 .50 K 10 1 .75 7.25 L 12 1 1.38 13.80 E 10 1 .40 3.90 D 10 1 .24 2.35 30 % .55 13358. TEST TUBES, Thick Wall, ordinary glass, without lip, culture tubes for bacteriological work, so-called Board of Health tubes. No A B C . D E Length, inches Diameter, inches % % '- % Per dozen 30 .35 .40 .45 .85 Per gross 2.80 3.10 3.60 3.90 8.20 13360. TEST TUBES, Thick Wall, ordinary glass, without lip, flat bottomed, so-called specimen tubes. No A B C Length, inches 4 Diameter, inches % % % Per dozen 35 .40 .45 Per gross 3.10 3.60 3.90 488 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 13364. No. 13370. No. 9332. No. 13382. No. 13390. No. 13366. No. 9330. No. 9334. No. 13386. No. 13400. 13364. TEST TUBES, Thin Wall, non-corrosive glass, with lip, for chemical work. No A B C D Length, mm 100 120 150 175 Diameter, mm 12 15 18 22 Per dozen $0.25 .30 .35 .65 Per gross 2.15 2.65 3.05 5.30 13366. TEST TUBES, Thick Wall, non-corrosive glass, without lip, for bacteriological work. No A B C D Length, inches 3 4 5 Diameter, inches % % % % Per dozen 40 .45 .50 .55 Per gross 3.40 3.80 4.30 4.65 E 200 25 .70 6.60 E 8 1 1.10 9.90 13370. TEST TUBES, Thick Wall, Pyrex glass, without lip, for combustion and ignition purposes, thick- ness of wall, about 1M> mm. No. Length, mm.. . Diameter, mm. Per dozen Per gross A 100 16 1.25 12.50 B 125 16 1.50 15.00 C 150 19 1.80 18.00 9330. 9332. 9334. 13382 13386 D 200 25 7.20 72.00 .90 .90 .90 TEST TUBES, Butter Fat Oil, plain, 9x?4 inches per dozen TEST TUBES, Butter Tat Oil, with line 5 inches from bottom per dozen TEST TUBES, Cream, heavy, for samples, 5x1% inches per dozen TEST TUBES, Ignition, with bulb at bottom, see Reduction Tubes. TEST TUBES, Potato Culture, ordinary glass, with lip, with constriction and bulb at the bot- tom. Length, 150 mm; diameter, 18 mm per dozen .90 TEST TUBE, Titer Tube, ordinary glass, with lip, for determining the melting and solidifying points of fats, and waxes. Length, 4 inches; diameter, 1 inch; thickness of wall, about 1 mm. (See Journal of the Association of Official Agricultural Chemists, Vol. II, No. 3, part II, November 15, 1916, page 303; Journal of Industrial and Engineering Chemistry, Vol. X, No. 4, for April 1918, page 317) 90 13390. TEST TUBES, Wassermann, Thin Wall, non-corrosive glass, with lip, for serological work. Length, mm 75 100 Diameter, mm 10 12 Per dozen 20 .25 Per gross 2.00 2.15 13394. TEST TUBES, Opaque Fused Silica, heavy wall, with lip. Length, inches 4 5 6 7 Diameter, inches V> % % % Each 1.06 1 50 2.20 2.81 13396. TEST TUBES, Transparent Quartz, valuable for rapid heating, since they may be applied to the hottest flame without fear of cracking. Length, mm 100 100 120 125 150 150 Diameter, mm 10 15 15 20 20 25 Each 1.32 3.12 3.60 4.80 5.40 6.90 TEST TUBE BRUSHES, see Brushes. 13400. TEST TUBE FILLING ATTACHMENT, for measuring out exact quantities of culture media and other chemical fluids. Consists of a separatory funnel with three-way stop-cock, to one arm of which is attached a graduated side tube. Capacity, 250 cc 3.50 TEST TUBE HOLDERS, see Clamps. TEST TUBE SUPPORTS, see Supports. CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 489 No. 13410. No. 13412. No. 13416. TESTING MACHINES FOR YARN, CLOTH, PAPER AND RUBBER 13410. TESTING MACHINE, Yarn, Hand Operated, constructed on the dead weight lever or pendulum principle, without springs or delicate parts to wear out or cause trouble. The machine will take 54 inch skeins, but may be used on 36 inch skeins by the addition of an extension hook. For short single strands special clamping screws may be obtained. The pull is registered automatically by the pointer on the dial until reset by the operator. With 9 inch heavy iron hand wheel, mounted on oak back board, with all metal parts finished in black enamel and nickel-plate. Capacity, pounds 100 150 200 250 Each (F. O. B. Factory) $62.50 67.50 74.75 80.00 Note: — These machines are not carried in stock and we can not guarantee immediate delivery. 13412. TESTING MACHINES, Cloth and Paper, Hand Operated, similar in construction to No. 13410, but with clamps for use with cloth or paper, designed to make various styles of tests. The open space back of the gripping surfaces allows large samples to be used without cutting or strip- ping. Mounted on oak back board with iron brackets for attachment to wall. Total length of machine, about 5 feet. Capacity, pounds 100 150 200 250 Each (F. O. B. Factory) 90.00 104.50 112.50 163.50 Note: — These machines are not carried in stock and we can not guarantee immediate delivery. 13416. TESTING MACHINE, Rubber, for Power Operation, vertical type, designed to be fastened to the wall. The construction is similar to that of the textile testers described under Nos. 13410 and 13412, but modified to meet the requirements of the rubber trade. The dial is gradu- ated with two rows of figures, the outer reading from 0 to 250 pounds in 1 pound divisions, the inner from 0 to 50 pounds in }£ pound divisions. The shift is made by removing the lower weight from the lever. The stretching screw is 1% inches in diameter and has a maximum stroke of 48 inches, the length being controlled by a vertical rod carrying two adjustable collars which mark the starting point and the reverse. After each test the machine reverses automatically, stopping in the proper position to receive a new sample. The normal speed of 20 inches per minute of the stretching screw may be varied as desired. A graduated brass scale at the left of the machine carrying two riders connected by a graduated steel tape ena- bles the total stretch of the sample or the distance between any two marks to be read to 1£0 of an inch. This machine can be arranged to test fabrics, cord, paper, twines, yarn and other materials as well as rubber. Total length of machine, 7 feet; power required to operate, % h. p. With one pair of clamps and pulley for belt, but without motor. F. O. B. Factory 350.00 Note: — This machine is not carried in stock aand we can not guarantee immediate delivery. 13417. CLAMPS, Flat Grip, for use with Xo. 13416 to adapt it for paper testing. Per pair (F. O. B. Factory) 45.00 For other PAPER TESTING MACHINES, see Paper Testing Apparatus. TEXTILE BALANCES, CONDITIONING OVENS, etc., write for information. 490 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. THERMIT FOR LABORATORY EXPERIMENTS We list the necessary equipments for a series of four interesting experiments with Dr. Gold- Schmidt's Thermit, a compound of a metallic oxide and granulated aluminum which, when ignited, starts a chemical reaction which will produce a temperature of 3000° C. This is now used extensively in welding fractures in iron castings and rails, as the molten thermit iron has the property of melting the surface of the iron it comes in contact with, and forming a solid mass. 13418. THERMIT, Experiment I. Welding a small piece of steel to a plate. Steel Plate, %6 inch thick. 2 Cans Thermit. 2 Pouring Cups. Bottle Ignition Powder. Pair Dark Glasses to protect Eyes. Complete set " $2.50 13419. THERMIT, Experiment II. Burning a hole through a plate. Steel Plate, 9 inch square x % inch thick. 4 Packages Plugging Material. Tripod. Bottle Ignition Powder. 2 Cans Thermit. Pair Dark Glasses. Tapping Spade. Large Crucible. Shipping Weight, 102 Ibs. Complete set 20.00 13420. THJ3RMIT, Experiment III. Welding a large boss to a steel plate (showing the manner of weld- ing in industrial uses). 2 Steel Plates, % inch. 2 Fire-Brick Molds, i . Large Crucible. Tripod. Bottle Ignition Powder. 2 Welding Portions. Package Luting Material. Tapping Spade. 2 Packages Plugging Material. Pair Dark Glasses. Shipping Weight, 152 Ibs. Complete set 21.50 13421. THERMIT, Experiment IV. Pipe welding. This experiment shows the following peculiar char- acteristics of the slag: First, its very high temperature; second, that it sets at a very high temperature; third, that in plastic condition it is highly refractory remaining in a layer distinct from the steel. 4 Pieces Standard Pipe, 6x1 inches. 3 Welding Portions. Mold. Small Crucible. Pair Tongs. 1 Set Clamps. Bottle Ignition Powder. Pair Dark Glasses. Shipping Weight, 86 Ibs. Complete set 35.00 13422. THERMIT COMBINATION SET, suitable for all four experiments. Shipping weight, 270 Ibs. 65.00 13423. THERMIT COMBINATION SET. Experiments I-III. Shipping weight, 230 Ibs 30.00 13424. THERMIT, black per pound .65 13425. IGNITING MIXTURE (8 oz. smallest quantity sold) per pound 1.50 THERMO-COUPLES, see Pyrometers. No. 13426. THERMOMETERS, ALL KINDS THERMOMETERS FOR GENERAL USE 13426. THERMOMETERS, Solid Stem, Engraved Scale, for general use. Diameter of stem, about V* inch. Graduated in 1° divisions. No A B C D E F Range, degrees C 0 to 60 -10 to 110 0 to 150 0 to 200 0 to 250 0 to 350 Length, inches 10 12 12 14 14 16 Each 1.10 1.20 1.25 1.60 1.80 2.00 13428. THERMOMETERS, Solid Stem, Engraved Scale, same as No. 13426, but graduated in Fahrenheit scale, in 2° divisions. No A B C Range, degrees F 10 to 220 30 to 400 30 to 650 Length, inches 12 14 16 Each 1.20 1.60 1.80 13430. THERMOMETERS, Solid Stem, Engraved Scale, same as No. 13426, but with double scale. No A B C Range, degrees C -10 to 110 0 to 200 0 to 350 Range, degrees F 10 to 220 30 to 400 30 to 650 Each 1.80 2.00 2.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 491 ----- Xo. ism No. 13444. No. 13464. 13432. THERMOMETERS, Solid Stem, Engraved Scale, similar to No. 13426, but more accurately grad- uated and furnished with factory certificate. No A B C Range, degrees C -10 to 100 -10 to 200 -10 to 320 Each $2.75 S.25 3.50 13436. THERMOMETERS, Enclosed Milk Glass Scale, diameter 8 to 10 mm, with Centigrade scale. No A B C Bange, 0° to, degrees C 110 200 350 Each 2.25 S.OO 3.50 13438. THERMOMETERS, Solid Stem, Engraved Scale, with fractional divisions, for general labora- tory work where highest degree of precision is hot required. With Centigrade scale. Diam- eter, about 7 mm. No A B C D E F G Bange, degrees C 0-50 0-50 0-100 0-100 100-200 0-200 100-200 Size of subdivisions, deg. C . . % }fo H Mo % % Mo Length, cm 30 38 40 60 50 60 60 Each 3.50 4^0 4.00 4.50 4^5 6.00 7.00 13442. THERMOMETERS, High Range, Solid Stem, Engraved Scale, filled with nitrogen above the mercury. Diameter, about 7 mm. No A B Bange, degrees C 100-400 100-550 Size of subdivisions, degrees C 2 2 Length, cm 40 40 Each S.50 5.00 13444. THERMOMETERS, High Range, same as No. 13442, but graduated in Fahrenheit scale. No A B Bange, degrees F 200-750 200-950 Size of subdivisions, degrees F 5 5 Length, cm 40 40 Each S.50 5.00 13446. THERMOMETERS, High Bange, Solid Stem, Engraved Scale, filled with carbon dioxide under pressure of 20 atmospheres. Diameter, 7 to 8 mm. No A B Bange, degrees C 100-500 180-550 Size of subdivisions, degrees C 1 1 Length, cm 40 40 Each 9.00 9.00 13452. THERMOMETER. Low Range, Solid Stem, Engraved Scale, for low temperatures. Bange, -20° to 40°C., in 1" divisions. Length, about 25 cm; diameter, 8 mm 2.00 1,",454. THERMOMETER, Low Range, Solid Stem, Engraved Scale, Alcohol Filled, for low tempera- tures. Bange, -50° to 50°C., in ige divisions. Length, about 30 cm; diameter about 8 mm 4.50 13456. THERMOMETER, Low Range, Solid Stem, Engraved Scale, Pentane Filled, for very low tem- peratures. Bange, -200" to 50°C., in 1° divisions. Length, about 35 cm; diameter, about 10 mm 10.00 1345S. THERMOMETER, Low Range, Solid Stem, Engraved Scale, Toluol Filled, for low temperatures. Bange, -100° to 50"C., in 1° divisions. Length, about 30 cm 7.50 THERMOMETERS, NORMAL OR PRECISION 13464. THERMOMETERS. Normal or Precision. Solid Stem. Engraved Scale, for precision measure- ments where highest accuracy is essential. Thermometers reading above 250°C. are filled with nitrogen. Graduated according to the requirements of the United States Bureau of Standards. Without certificate. No A B C D E F Range, degrees C -15 to 50 -15 to 100 -5 to 105 -10 to 110 0 to 250 0 to 300 Size of subdivisions, deg. C. ^0 1 % ^0 % 1 Length, cm 38 30 38 60 45 45 Each 12.00 8.00 10.00 18.00 9.50 7.50 13463. THERMOMETERS. Normal or Precision, same as No. 13464, but standardized by the United States Bureau of Standards, with certificate. No A B C D E F Each 15.00 14.00 16.00 24.00 15.50 15.00 492 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. 1 'AUJi" "1iU'"I"A'i1illl"liU>"J» No. 13500. No. 13506. 7373. THERMOMETER, Solid Stem, Engraved Scale, for Use with Moisture Testers. Length, 12 inches. Range, 0° to 200° Centigrade in 1° divisions. With factory certificate $2.00 13486. THERMOMETER, Titer Test, Solid Stem, Engraved Scale, according to the requirements of the Association of Official Agricultural Chemists. Range, 10° to 65° C., in 1/10° divisions with zero point marked, and with reservoirs at upper end and between 0° and 10° marks. Length of thermometer, 38 cm; length of bulb, 3 cm; distance between top of bulb and 10° mark, 3 to 4 cm; diameter of stem and bulb, about 6 mm. (See Journal of the Association of Official Agri- cultural Chemists, Vol. II, No. 3, Part II, November 15, 1916, page 302; Journal of Industrial and Engineering Chemistry, Vol. X, No. 4, for April 1918, page 317) 9.90 THERMOMETER FOR SPECIAL USES 13496. THERMOMETERS, Armored, Solid Stem, Engraved Scale, with armor of seamless steel tubing, nickel-plated, with lower end perforated around bulb to permit circulation. Thermometer is suspended from screw cap and easily removed. Scaled for 3 inch immersion. 13497. 13498. 13499. 13500. 13502. No A B C Range, degrees F 0-220 30-400 30 600 Size of subdivisions, degrees F.. 2 2 2 Length, inches 12 14 16 Each 5.00 5.80 6.60 THERMOMETER TUBES, extra, for No. 13496. No ABC Each 2.50 3.30 4.15 THERMOMETERS, Armored, same t is No. 13496, but with Centigrade scale. No A B C Range, degrees C 0-100 0 200 0 300 Size of subdivisions, degrees C. . 1 1 1 Length, inches 12 14 16 Each 5.00 5.80 6.60 THERMOMETER TUBES, extra, for No. 13498. No ABC Each 2.50 3.30 4.15 I) 30-750 2 16 8.25 D 5.80 D 0-400 1 16 8.25 D 5.80 E 100-950 5 16 11.55 E 9.10 E 50-510 2 16 11.55 E 9.10 Threaded for inch pipe and fitted with 2l/2 3V> 4% 2.30 3.00 3.65 13503. 13506. WELLS, Steel, for use with Nos. 13496 to 13499. screw plug. Length below thread, inches ............. iy, Each ............................................. 1.65 THERMOMETERS, Armored, Asphalt and Sand Testing, Solid Stem, Engraved Scale, with seam- less brass tubing, nickel-plated, and with pointed bulb to facilitate introduction into the sample. Constructed of glass tubing with walls of double thickness to withstand severe usage. Scaled for 3 inch immersion, except No. A, which is for total immersion. No .............. ..,. ............................... A B C Range, degrees F ................................. 200-400 100-600 200-750 Size of subdivisions, degrees F ..................... 5 5 5 Length, inches ................................... 6 16 16 TTse .............................................. inspection asphalt sand Each ............................................ 5.00 6.60 8.25 THERMOMETER TUBES, extra, for No. 13502. No .............. A B C Each ....................................................... 2.50 4.15 5.75 THERMOMETERS, Armored, Asphalt, with Protected Bulb, and engraved stem. The bulb is im- mersed in a bath of mercury contained in the long slender steel cup forming ths stem, afford- ing protection and making it almost as quick reading as a bare glass bulb. Length of case, 10 inches. No ................................................... A B Range, degrees F ............................................... 200-400 200-650 Size of subdivisions, degrees F .................................. 2 5 Each ...................... 6.60 6.60 CEXTEAL SCIENTIFIC CO., CHICAGO, U. S. A. 493 No. 13514. Nos. 13518-9. Nos. 13518-9. No. 13522. 13507. THERMOMETER TUBES, extra, for No. 13506. Xo A B Each..... $3.30 3.30 No 13508 13508. THERMOMETER, Automatic Alarm, for giving an alarm the instant the tem- perature registers a given degree. Consists of a straight mercury tube, into the bore of which a fine platinum wire is fused at 32° F., or at any other degree desired. Through a non-sparking relay attachment a bell is made to ring at practically any distance from the thermometer itself, at the exact moment the temperature where the instrument is located reaches the danger point. Strongly constructed and fully protected by a heavy metal weather-proof case, which allows circulation of air. May be installed in three different ways: (1) one thermometer and simple alarm; (2) more than one thermometer and simple alarm; (3) more than one thermometer and an- nunciator alarm showing exact location of danger point. In ordering, kindly state the tem- perature at which alarm is to be given. Complete with relay, but without batteries, bell, or wire 18.00 13510. THERMOMETER, Automatic Alarm, similar to No. 13508, but arranged to ring at either of two temperatures desired, which must be specified when ordering. Complete with relay, but with- out batteries, bell, or wire 24.30 13514. THERMOMETER, Bake Oven, Medium Grade, consisting of a glass tube, mercury-filled, mounted on 5-inch flanged metal scale with sand blast finish and white figures. With round removable base with asbestos mat attached. Range, about 100° to 600° F 1.50 THERMOMETER, Beckmann, for the exact determination of slight changes in temperature. Widely used in calorimetry and in boiling and freezing point determinations. Consists of a capillary of normal glass graduated to 1/100 degree over a range of 5° or 6° C., with an auxiliary scale at the top graduated from -10° to 120° C., in 2° divisions, sealed in a glass jacket with metal cap. The thermometer may be set to read at any temperature between -10° and 120° C. Constructed and graduated according to the requirements of the United States Bureau of Standards. 13518. Without certificate 20.00 13519. With Bureau of Standards certificate 32.50 THERMOMETER, Beckmann, improved, similar to Xo. 13518, but with improved method of ad- justment of temperature. In the reservoir beneath the auxiliary scale is a short capillary (a), the opening of which is adjusted to deliver a drop of mercury of sufficient size to produce a fixed change of temperature in degrees C., the exact amount of this change being engraved on the scale of the thermometer. This improved construction obviates the necessity of tapping the mercury column, with the consequent danger of breakage. It also makes easier the return of excess mercury from the reservoir to the bulb which takes place automatically if the ther- mometer is held in a perpendicular position. Mercury from the reservoir may be transferred to the side arms by merely inclining the thermometer. Graduated according to the require- ments of the United States Bureau of Standards. 13-.22. Without certificate 25.00 13523. With Bureau of Standards certificate 37.50. 494 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 13548. No. 13562. No. 13564. THERMOMETERS, Calorimeter, Solid Stem, Engraved Scale, as used with oxygen bomb calorimeters. Graduated to meet the requirements of the United States Bureau of Standards. No A B Range, degrees C 18-30 20-30 Size of subdivisions, degrees C 1/50 1/100 Length, inches 18 24 13528. Without certificate $15.00 20.00 No. 13558. 13529. With Bureau of Standards certificate 30.00 35.00 THERMOMETERS, Calorimeter, Solid Stem, Engraved Scale, as used with Parr Calorimeters. Graduated to meet the requirements of the United States Bureau of Standards. No A B Range, degrees F 65 to 90 65 to 105 Size of subdivisions, degrees F 1/20 1/20 13532. Without certificate 10.00 13.00 13533. With Bureau of Standards certificate 12.00 15.00 THERMOMETERS, Gas Calorimeter, Solid Stem, Engraved Scale, according to the recommenda- tions of the American Gas Institute, as used in Junker and other gas calorimeters. Length, about 45 cm; diameter, about 8 mm. (See Report of Committee on Calorimetry for 1912.) No A B Range 60° to 110°F. 15° to 40°C. Size of subdivisions, degrees 1/10 1/10 13536. With factory certificate. 18.00 18.00 13537. With Bureau of Standards certificate 26.00 25.00 13540. THERMOMETER, Gas Calorimeter, Solid Stem, Engraved Scale, high grade. Graduated from 30° to 150° F., in 1/10° divisions 8.50 13546. THERMOMETER, Clinical, One Minute, first grade, with magnifying tube, in hard rubber case, with factory certificate 1.50 13548. THERMOMETER, Clinical, Veterinary, first grade, pear-shapea bulb, ring top, with magnifying tube, in hard rubber ease, with factory certificate 1.75 THERMOMETERS, Dairy, see Milk Testing Apparatus. 13558. THERMOMETER, Dough Testing, of glass in 7 inch nickel-plated iron case, with 11 inch steel stem. The scale is of silvered metal with black rilled figures and graduations. Range, 30° to 120° F 8.00 13562. THERMOMETER, Household, standard grade, 10 inch, heavy japanned tin case, accurately tested. Approximate range.— 20° to 120°F 1.35 13564 THERMOMETER,, Household, 8 inch, metal scale, oak back, beveled edge, with brass guard over bulb. Approximate range,— 20° to 120°F 1.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 495 No. 13568. ^•j.Lrg^H^H Ko' 1358t No- 1359°- No. 13592. No. 13594. No. 13578. 13568. THERMOMETER, Incubator, Solid Stem, Engraved Scale, with enlargement in stem to prevent slipping through hole in stopper. Length, about 20 cm. Range, 0" to 50° C., in 1° divisions .-- $2.50 13572. THERMOMETER, Maximum Registering, XT. S. Weather Bureau Pattern, 12 inch, cylindrical bulb, graduation etched on tube. The tub? is mounted on an aluminum scale on which is marked every 5 degree line of the scale, and the figures every 10 degrees. Has brafs insulat- ing support and binding screws. Approximate range, -30° to 120° F. With manufacturer's certificate 7.20 13574. 13578. THERMOMETER. Minimum Registering, U. S. Weather Bureau Pattern. Same general descrip- tion as No. 13572. Mercury filled tube. With manufacturer 's certificate 6.60 THERMOMETESS, Maximum and Minimum Registering, TJ. S. Weather Bureau Pattern. Same thermometers as Nos. 13572 and 13J>74, but with special insulating support. Mounted on ma- hogany finish back, 17x5 inches, with manufacturer's certificate for each thermometer. Per set 14.40 13579. THERMOMETER, Maximum, only for No. 13578. With manufacturer's certificate 7.20 13580. THERMOMETER, Minimum, only for No. 13578. With manufacturer's certificate 6.60 13584. THERMOMETER, Maximum and Minimum Registering, Six's Pattern, in japanned tin ease with metal scale. Length, 8 inches; approximate range, — 20° to 120°F. Complete with horseshoe magnet for resetting 4.20 13590. THERMOMETERS, Metal Scale, highest grade, with scale of oxidized brass in black japanned tin case. Length, 10 inches. No A B C Range, degrees F -20 to 120 0 to 220 50 to 350 Each 1.25 1.25 1.50 13592. THERMOMETER, Metal Scale, with Copper Cup, highest grade, for determining the average temperature of oil or other liquids in tank ears or tanks and securing a sample at the same time. Bange, 10° to 220° F. Length, 12 inches 3.30 13594. THERMOMETER, Metal Scale, Sugar Factory, standard grade, with magnifying tube filled with mercury, silvered brass seale with black figures, and brass screw clamps. Bottom of copper case is closed to permit samples to be taken. Length, 12 inches. Bange, about 0° to 150° Centi- .e grade 2.75 THERMOMETERS, Metal Frame, Straight and Angle Stem, for steam boilers, water heaters, oil stills, etc. Send for special bulletin. 496 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 13598. "T— 1 • iu > No. 13612. i i_ :--H-^rpgs!±^!L^ No. 13618. 13598. THERMOMETER, METALLIC, Demonstration Form, with glass back to show the internal mechanism, which consists of a strip of two metals soldered together and connected with an index hand by a multiplying lever. Diameter 6 inches. Range, — 50 to 150 degrees F. . $4.50 THERMOMETERS FOR OIL TESTING 13606. THERMOMETER, Paper Scale, for Cold Test, graduated from -20° to 120° F., in 2° divisions. For determining the congealing point of lubricating oils. Length, 8 inches 3.30 13608. THERMOMETER, Paper Scale, for Flash and Fire Test, graduated from -20° to 230° F., in 1° divisions. For use with No. 9676 Open Fire Tester. Length, 12 inches 3.30 13610. THERMOMETER, Paper Scale, for Wax Test, graduated from 90° to 150° F., in %° divisions. For determining melting point of waxes, paraffines and greases. Length, 12 inches. . . . 4.40 13612. THERMOMETER, Solid Stem, Engraved Scale, for Cold Test, graduated from -20° to 140° F., in 2° divisions, for determining the congealing point of lubricating oils. Length, 8% inches 2.50 13613. THERMOMETER, Solid Stem, Engraved Scale, for Cold Test, graduated from -40° to 100° F., in 1° divisions. Length, 30 cm 2.00 13614. THERMOMETER, Solid Stem, Engraved Scale, for Cold Test, same as No. 13613, but graduated from -40° to 40° C., in 1° divisions. Length, 25 cm 2.00 13616. THERMOMETERS, Solid Stem, Engraved Scale, for Distillation. Pointed for 3 inch immersion. No A B C Range, degrees F 30 to 400 30 to 750 100 to 950 Size of subdivisions, degrees F 2 2 5 Length, inches 15 15 16 Each - 4.15 8.25 9.10 13618. THERMOMETERS, Solid Stem, Engraved Scale, for Distillation. Same as No. 13616, but grad- uated in Centigrade scale. No A R C Range, 0° to, degrees C 200 400 510 Size of subdivisions, degrees C 1 1 2 Length, inches 15 15 16 Each 4.15 8.25 9.10 13622. THERMOMETER, Solid Stem, Engraved Scale, for Distillation of Gasoline, graduated to read from 0° to 270° C. Made according to specifications of the United States Bureau of Mines. (See Technical Paper 166, May 1917, page 21) 4.15 13624. THERMOMETER, Solid Stem, Engraved Scale, same as No. 13622, but graduated from 20° to 520° F. in 2° divisions 4.15 9663. THERMOMETERS, Solid Stem, Engraved Scale, for Flash Test, for use in oil cup of No. 9662 Bureau of Mines Flash Tester. Graduated in % degree divisions. No A B Range, degrees C 0-50 40-110 Each 8.25 8.25 9669. THERMOMETERS, Solid Stem, Engraved Scale, for Flash Test, for use in oil cup of No. 9668 Bureau of Mines Flash Tester. With round bulb, graduated in 1 degree divisions. No A B C Range, degrees C 100-210 200-310 300-410 Each 8.25 8.25 9.90 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 497 No. 13636. No. 13640. No. 13652. NO. 13658 (glass tube only). f ^^•••^^ No. 13662. 13634. THERMOMETER, Solid Stem, Engraved Scale, for Flash and Fire Test, for low flashing oils. Graduated from -10° to 110° C., in 1° divisions. According to the specifications of the Ameri- can Society for Testing Materials. Length, 12 inches $2.50 13636. THERMOMETERS, Solid Stem, Engraved Scale, for Flash and Fire Test, pointed for 1 inch im- mersion. Length, 15 inches. No A B C D Range, 20° to, degrees F 220 300 400 500 600 760 Size of subdivisions, degrees F 1122222 Each 2.50 2.65 3.30 3.95 4.62 4.95 5.80 13640. THERMOMETERS, Solid Stem, Engraved Scale, for Viscosity, graduated in 1/5° divisions. Length, 8 inches. No A B C Range, degrees F 98 to 108 128 to 138 208 to 218 For measuring viscosity at, degrees F 100 130 Each 5.00 5.00 5.00 13642. THERMOMETERS, Solid Stem, Engraved Scale, for Viscosity, graduated in 1° divisions. Length, 8 inches. Xo A B C D E Range, degrees F 55 to 110 80 to 110 100 to 150 100 to 220 180 to 220 Each 2.50 2.50 2.50 2.50 2.50 9762. THERMOMETERS, Solid Stem, Engraved Scale, for use with Xo. 9760 Saybolt Viscosimeter. No A B C Range, degrees F 70 to 110 100 to 140 180 to 220 Each 3.60 3.60 3.60 9767. THERMOMETER, Solid Stem, Engraved Scale, for use with Xo. 9766 Scott Viseosimeter. Gradu- ated from 50° to 120° F., in 1/5°, for use with lubricating oils 8.25 9664. THERMOMETER, Solid Stem, Engraved Scale, for Water Bath of Xo. 9662 Bureau of Mines Flash Tester. Graduated from 0° to 85° C., in 1° divisions. With cylindrical bulb 8.25 13652. THERMOMETER, Solid Stem, Engraved Scale, for Wax Test, graduated from 80° to 150° F., in 14° divisions, for determining the melting point of waxes, paraffines, and greases. Length, 10 inches 3.30 13658. THERMOMETER, Pocket, Solid Stem, Engraved Scale, in spiral-ribbed aluminum case. Length, ~> inches. Range, 0* to 220° F., in 2° divisions 2.50 13660. THERMOMETER, Pocket, same as No. 13658, but with Centigrade scale. Range, 0° to 100° C., in 1° divisions 3.00 13662. THERMOMETER, Pocket, Maximum Registering, Solid Stem, Engraved Scale; in aluminum case. Length, .", inches. Range, 0° to 220° F., in 2° divisions 4.15 13663. THERMOMETER, Pocket, Maximum Registering, same as Xo. 13662, but with Centigrade scale. Range, 0° to 100° C., in 1° divisions 4.15 498 CENTEAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 13666. No. 13670. 13666. THERMOMETERS, Recording, with clock movement for revolving the chart, and a steel coil spring for actuating the recording pen arm; a flexible connecting tube through which the ac- tion of the mercury in expanding or contracting is transmitted from the sensitive element (the bulb) to the coil spring; and a bulb or sensitive element which is inserted at the point whose temperature is to be determined. The spring, the steel connecting tube, and the bulb are welded together, forming a hermetically sealed mercury filled system. In black enameled iron case, with nickel-plated ring, complete with 100 charts divided for making one revolution in seven days, extremely sensitive bulb 18 inches long, 10 feet of flexible protected capillary tubing (in case a greater length of tubing is desired, state exact length in order and add 40c per foot for each foot over 10) and supply of ink and pens. No A B C D Range -40° to 120°F. 30 to 230°F. -20 to 60°C. 200 to 1000°F. Size of subdivisions, degrees 2 5 1 10 Each $60.00 60.00 60.00 60.00 Note: — Thermometers of other ranges will bs furnished on application; also for 24 hours instead of seven days. 13667. CHARTS for No. 13666, 8 inches in diameter, for 7 day period. No "... A B C D Per hundred 1.75 1.75 1.75 1.75 13670. THERMOMETER, Recording, Self Contained, for obtaining continuous weekly records of weather, room or incubator temperatures. The case is 12 inches in diameter, finished in weather-proof black, with polished bronze hinged front. Range, 0° to 130°F. in 2° divisions. Complete with lock and key, one hundred 7-day charts and bottle of special recorder ink. 50.00 13671. CHARTS for No. 13670 Per hundred 3.30 13676. THERMOMETER, Recording (Thermograph). Made in America. A most accurate thermometer which will not vary its standard for years. A complete record is given by a pen upon a printed chart for an entire week, and by its form the exact thermometric reading can be seen at any moment, as well as the varying line traced by the pen for the time preceding. The charts are changed at the beginning of each week and can be retained as a record for the entire year. Mechanism consists of a spiral lamina of non-rusting material, which is exposed to the atmosphere at the end of the case. It is extremely sensitive and, having no levers in its con- struction, is very rigid. In non-corrosive metal case with glass front and screened openings on three sides about the lamina, and with storage space for charts. Range, 0° to 100° F. in 2° divisions. May ordinarily be used for any range of 100° F. between — 20° and + 250" by means of No. 13683 Unfigured Charts. Complete with full directions for use, charts for one year, pen and ink 50.00 (For illustration of No. 13676, see page 499.) CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A, 499 No. 13712. No. 13716. No. 13720. 13678. THERMOMETER, Recording (Thermograph). Same as No. 13676, but with charts from 20° to 120°F $50.00 13680. THERMOMETER, Recording (Thermograph). Same as No. 13676, but with unflgured charts for a range of 100°F. in 2° divisions 50.00 13681. THERMOGRAPH CHARTS, 0° to 100°F., for use with No. 13676. In boxes containing a year's supply Per box 2.00 13682. THERMOGRAPH CHARTS, 20° to 120°F., for use with No. 13678. In boxes containing a year's supply Per box 2.00 13683. THERMOGRAPH CHARTS, Unfigured, for use with No. 13680. Range, 100°F. in 2° divisions. In boxes containing a year's supply Per box 2.00 13689. THERMOGRAPH CHARTS, for use with old style imported high drum thermographs. Style No. 46. Range — 62° to +128°F. In boxes containing a year 'a supply Per box 2.25 13691. THERMOGRAPH CHARTS, for use with old style imported low drum thermographs. Style No. 37. Range 0° to 100°F. In boxes containing a year's supply Per box" 2.50 13697. BARO-THERMOGRAPH CHARTS, Style No. 20. In boxes containing one year's supply. ." Per box 3.00 13710. THERMOMETER, Soil, Standard Grade, magnifying tube, mercury-filled, mounted on 15 inch turned mahogany frame with oxidized brass scale, and with pointed metal end. Range, -30° to 180° F ! 2.30 13712. THERMOMETERS, Soil, as used by the New York Agricultural Experiment Station. With solid stem engraved scale thermometer mounted in turned wood case with upper part cut away to expose 10 inches of the scale from about 20° to 120° F. Both ends are protected by metal ferrules. J No A B C For use at depth, inches 12 24 36 Each 9.00 9.50 12.50 13716. THERMOMETER, Three Scale, boxwood, F., B. and C. scales 80 13720. THERMOMETER, Weather Bureau Standard, 12 inch, cylindrical bulb, graduation etched on tube. The tube is mounted on an aluminum scale on which is marked every 5 degree line of the scale, and the figures every 10 degrees. Has brass insulating support and binding screws. Approximate range, -30° to 120^. With manufacturer's certificate 6.00 13724. THERMOMETER, Window, for weather observations, with magnifying tube, alcohol filled, mounted on nickel-plated metal back, with brackets for attachment to window frame. Length, 10 inches; approximate range, — 40° to 120°F 1.20 13728. THERMOMETER, Wood Frame, with solid stem, engraved scale thermometer. Floats hori- zontally in liquids. No metal to corrode. Length, 12 inches; range, about -20° to 120° F. .80 500 CENTEAL SCIENTIFIC CO., CHICAGO, TI. 8. A. No. 13756. No. 13748. No. 13744. 13730. THERMOMETER READING ATTACHMENT, designed especially for use with Calorimeter Ther- mometers. Supported by the thermometer stem, thereby maintaining a constant angle of vision over the whole scale $3.00 13731. THERMOMETER READING ATTACHMENT, same as No.' 13730, but without support. . 2.00 1984. THERMOMETER READING ATTACHMENT, consisting of a nickel-plated brass clamp to fasten 011 the thermometer stem with an adjustable eyepiece 2.00 13740. THERMO-REGULATOR, Electric, DeKhotinsky Bimetallic, made from invar-brass ribbon. It can be set at any desired temperature from that of the surrounding atmosphere or less, to 250° C. or higher ;u necessary. The precision of action of this thermo-regulator is 1/4° C. No relay is required in connection with it. Maximum capacity, iy2 amperes 10.00 13744. THERMO-REGULATOR, Electric, DeKhotinsky Standard, for precision work in temperature con- trol of water baths, thermostats, etc. It possesses a number of advantages over the usual form. To reduce the lag and to make it respond quickly to changes of temperature it is made of steel, which has about 66 times the thermal conductivity of glass, and is filled with mercury which has about 60 times the conductivity of toluene, which is often used to fill thermo- regulators. Attached to this steel tube is a regulating cap provided with a platinum point, •which makes contact with the surface of the mercury in a small glass capillary tube, so that the contact is visible. This capillary is ground to fit exactly the metal parts of the head so that the platinum contact point is exactly centered. When the regulator is to be used in water it must be ordered enclosed in a thin-walled brass tube to prevent rust. The sensitiveness of this thermo-regulator depends solely on tho relation between the diameter of the capillary and the capacity of the steel tube and is almost unlimited. A relay must be used in connection with this thermo-regulator, as the current which passes through the mercury-platinum contact must be kept infinitesimally small. Price dependent upon length and accuracy required. In ordering, specify the capacity of the bath, depth of water, kind of current and accuracy of regulation desired. 13748. RELAY, DeKhotinsky Iron Clad, for use with No. 13744 for accurate temperature regulation. This must be ordered in connection with No. 13744, and the same information must be fur- nished. When ordered, complete directions will be furnished including a wiring diagram show- ing all connections to be made. Price dependent upon conditions to be met. 13754. THERMO-REGULATOR, Electric, simple form, consisting of a strip of hard rubber and metal riveted together, the difference in their expansion causing the strip to bend, thus opening or closing an electric circuit through the platinum contact points. Useful as a fire alarm, and in roughly controlling the temperature in hot-houses, incubators and other places where a constant temperature is essential 2.25 13756. THERMO-REGULATOR, Electric, with condenser, for use in incubators. Will control tempera- tures automatically to %° C., through a range from 30° C. to 6C° C. Very simple in construc- tion and constant in operation. For full description, see No. 7908 11.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 501 N No. 13762. No. 13766. No. 13770. No. 13772. No. 13774. No. 13778. No. 13780. No. 13784. No. 13786. No. 13806. 13762. THERMO-REGULATOR, Gas, Dunham's, of glass, for regulation of gas flame. Without mer- cury $2.00 13766. THERMO-REGULATOR, Gas, Greenman Mercury, constructed entirely of steel, widely used in connection with Greenman Burner No. 2102 for heating and regulation of incubators. A brass jacket is supplied for the thermo-regulator which is to be filled with glycerine. Length of thermo-regulator tube, 10 inches; diameter of outer jacket, 1 inch. With inlet and outlet tubes threaded with % inch iron pipe thread for permanent connection with gas supply. Without mercury .' 13.20 13770. THERMO-REGULATOR, Gas, Mercury-Toluene type, of glass. Length, about 12 inches. 2.50 13772. THERMO-REGULATOR, Gas, same as No. 13770, but with a by-pass to keep flame burning. Without screw clamp 3.00 13774. THERMO-REGULATOR, Gas, same as No. 13770, but with reservoir and glass stop-cock to vary the amount of mercury 7.50 13778. THERMO-REGULATOR, Gas, Reichert's, of glass with brass adjusting screw. Length, 9% inches 4.80 13780. THERMO-REGULATOR, Gas, Reichert's improved, with stop-cock to prevent extinguishing the flame 6.00 13784. THERMO-REGULATORS, Gas, Roux Bimetallic, operating without the use of mercury or glass. Diameter of tube, 1 inch. Length, inches 10 12 Each 9.90 10.65 13786. GAS FILTER ATTACHMENT, for use with Nos. 13766 and 13784, for cleaning the illuminating gas of coal tar and other impurities. . . . : 5.40 For GAS PRESSURE REGULATOR for use with Thermo-Regulators, see No. 7070. THERMOS BOTTLES, see Vacuum Bottles. THERMOSTATS, see Physical Chemistry Apparatus. THISTLE TUBES, see Funnel Tubes. 13792. THREAD, Cotton, White, No. 70, in spools of 150 yards Per spool .10 Per dozen 1.00 13794. THREAD, Linen, Black, No. 30, in spools of 200 yards. Per spool .40 Per dozen 4.00 13796. THREAD, Silk, Black, No. A, in spools of 50 yards Per spool .10 Per dozen 1.00 13800. THUMB TACKS, stamped steel, made of one piece, head $£6 inch Per dozen .09 13806. TIME MARKER, Electrically Operated, with aluminum stylus, for use in connection with No. F783 Metronome (or other periodic circuit breaker) and a Kymograph (see No. F6065). Mounted on a 10 mm rod 22 cm long, for clamping to any support. Small and compact; positive in action . 6.75 502 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 13862. No. 13864. 13810. TIME SWITCH, for automatically disconnecting electrically operated instruments from the cir- cuit at the expiration of a given interval of time. Consists of a single pole knife switch oper- ated by a No. 3000 Interval Clock which may be set to throw the switch at the end of any in- terval from }4 minute up to 2 hours. For use in circuits up to 15 amperes. Convenient for use with electric centrifuges, incubators, sterilizers, shakers, etc. Complete as illustrated, mounted on slate base with binding posts $10.00 TIN BOXES, see Boxes. 13818. TONGS, Crucible, Single Bent, brass, with riveted joint. Length, 9 inches 65 13820. TONGS, Crucible, Single Bent, brass, nickel-plated, with riveted joint. Length, 9 inches. .95 13824. TONGS, Crucible, Double Bent, brass, with riveted joint. Length, 9 inches 35 13826. TONGS, Crucible, Double Bent, brass, nickel-plated, with riveted joint. Length, 9 inches .50 13830. TONGS, Crucible, Double Bent, steel, with riveted joint. Length, 9 inches 20 13832. TONGS, Crucible, Double Bent, steel, nickel-plated, with riveted joint. Length, 9 inches .30 13836. TONGS, Crucible, Double Bent, forged steel, nickel-plated, with lock joint. Length, 10 inches. With corrugated tips 3.00 13840. TONGS, Crucible, Double Bent, solid nickel, with riveted joint. Length, 9 inches 1.00 13842. TONGS, Crucible, Double Bent, solid nickel, with nickel-chromium tips, electrically welded on. The tips take on an adherent coating which ' protects hot platinum with which they come in contact. With riveted joint 3.25 13846. TONGS, Crucible, Double Bent, steel, nickel-plated with solid platinum tips; lock joint. Length, 8 inches. Price varies with market price of platinum. 13850. TONGS, Crucible, Double Bent, solid nickel, with solid platinum tips; lock joint. Length, 8 inches. Price varies with market price of platinum. 13854. TONGS, Crucible, Double Bent, forged steel, nickel-plated with solid Palau tips; lock joint. Length, 10 inches. Weight of Palau tips, about 4 grams 16.50 13858. TONGS, Crucible, Double Bent, steel, nickel-plated, with riveted joint. For use in handling cru- cibles and dishes in muffle furnaces. Length, 18 inches 3.00 13862. TONGS, Crucible, Single Bent, malleable iron, for heavy crucibles. Length, inches . . 1" " Each 1-50 1.65 13864. TONGS, Crucible, Double Bent, wrought iron, for heavy crucibles. Length, 30 inches. . . 1.80 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 503 O . No. 13866. No. 13870. No. 6020. No. 13876. No. 13878. No. 13882. No. 13890 (Tools only). No. 13894. 13866 13870, 6020 TONGS, Crucible, Double Bent, •wrought Iron, for lifting heavy crucibles vertically. Length, 33 inches. " For crucibles up to 4 inches $1.80 TONGS, Crucible, Julian's, steel, nickel-plated, for handling crucibles in a muffle furnace. Length, 20 inches . 2.50 TONGS, Cylinder or Crucible, with curved jaws. Designed especially for use with No. 5906 Baking Cylinder. Length, 24 inches 1.10 13876. TONGS, Cupel, steel, with bent flat ends. Length, 30 inches 1.25 13878. TONGS, Cupel, steel, with curved ends. Length, 30 inches 1.25 TONGS, Gas, see Pliers. 13882. TONGS, Scorifier, spring steel, light. Length, 30 inches 1.25 13888. TOOL HOLDER, with hollow wood handle and ten enclosed tools. Length of holder over all, 6 inches. Length of tools, 2 y2 inches .60 13890. TOOL HOLDER. Handle similar to that of No. 13888, but larger and better finished. Has 9 tools, as shown in the illustration. Length of handle over all, 7 inches. Length of tools, 3% inches 1.60 13894. TOOL SET in Case of polished hardwood, 16x8V>x3% inches, containing 6-in. and 1%-in. ratchet screw drivers, hand shave, hack saw frame with 11 blades and one bone saw, glass cutter, wood handle automatic drill, tool handle with 9 tools, nail set, prick punch, saddlers' drive i !. punch, solid punch, and oil stone 11.00 504 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. No. 13896. No. 13914. 13896. 13900. TOOL SET in Case of polished hardwood, lexS^xS1/^ inches, containing 6-in. steel try square, 6-in. iron level, double beam roller gauge, washer cutter, gunsmiths' screw driver, tool holder for small square shank tools, brass hammer, lever metal punch, 6-in. and l^-in. ratchet screw drivers, hand shave, hack saw frame with 11 blades and one bone saw, glass cutter, wood handle automatic drill, tool handle with 9 tools, nail set, prick punch, saddlers' drive punch, solid punch, and oil stone ........................................................ $18.70 TOOL SET in Chest of chestnut, panelled and nicely finished. Contains the following high grade tools. Panel saw, brace, 3 gimlet bits, 3 auger bits, 3 chisels, 2 screw drivers, hack saw frame, pocket level, countersink, scraper, hammer, tack hammer, tool handle with 10 tools, spoke shave, block plane, jack plane, 2-foot rule, try square, marking gage, nail sets, wing dividers, gas pliers, flat nose pliers, nippers, .saw file, oil stone, oil can, can of glue, and coping saw. Weight, 55 Ibs. ................................................................................. 27.00 Per bolt TOOLS, Miscellaneous, see various headings, as Calipers, Pliers, Hammers, etc. 13906. TOWELLING, Crash, good quality, 16 to 17 inches wide, in bolts of 50 yards Per yard TRANSITS, see Asbestos Slate. TRANSITS, see Surveying Instruments. TRAYS, Germinating, see Grain Testing Apparatus. 13914. TRAYS, Glass, Photographic, of clear flint glass. No Size, inches Each . .17 7.50 B .27 .30 sy. 13916. 13920. TRAY, Glass, heavy, 6x8xiy2 inches deep TRAYS, Metal, Photographic, wire bound and coated with acid-proof japan. .40 No. Size, inches Each TRAYS, Sampling, see Sampling Apparatus. TRAYS, Slide, see Microscope Accessories. TRAYS for Soil Analysis Work, see Soil Analysis Apparatus. TRIANGLES, Draftsman's, see Drawing Instruments. TRIANGLES, Glass Dessicator, see No. 3804. 13932. TRIANGLES, iron wire, twisted. No Length of side, inches Each Per dozen 13934. TRIANGLES, iron wire covered with pipe stems. No Length of side, inside, inches Each Per dozen . B 7x9 .45 C 8x10 .60 D 10x12 .90 C xioy2 .70 .30 E 16x20 2.50 A 1% .07 .65 .05 .40 B 2 .07 .70 .05 .40 C 2% .08 .75 .05 .40 D 3 .08 .80 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 505 No. 13936. No. 13956. No. 13958. No. 13960. No. 13966. 13936. TRIANGLES, iron -wire covered with pipe stems having raised centers, so that the crucible rests on these points. No A B C Length of side, inside, inches 2 2M> 3% Each $0.09 .10 .12 Per dozen 90 1.00 1.20 13940. TRIANGLES, Nichrome wire, melting point about 3000° F., non-corrodible, costing but one-six- teenth as much as platinum and lasting longer in service. No A B C D Length of side, inside, inches 1% - 2% 3 Each 16 .16 .22 .22 13942. TRIANGLES, Nichrome •wire, covered with fused silica tubes, superior to any triangles yet pro- duced. No A B C D Length of side, inside, inches 1% 2 2% 3 Each 31 .31 .44~ .50 13944. TRIANGLES, Hoskins' Chromel, made of h?avy square-section wire, free from iron, and highly resistant to acids, oxidation, and fusion. No A B C D Length of side, inside, inches 1*4 2 2% 3 Each 28 .28 .40 .40 TRIANGLES, Platinum, see Platinum Ware. 13950. TRIANGLE HOLDER, adjustable, for Triangles No. 10842, with clamp for attaching to sup- 1.25 13956. 13958. port TRIPODS, iron, small, for alcohol lamps. Height, 6 inches; diameter, 3»4 inches TRIPODS, iron, japanned, with easily removable legs and wide rim. Height, 9 inches. Diameter, outside, inches.. Each o .30 6 .35 13960. TRIPODS, iron, japanned, same as Xo. 13958, with concentric rings. No A B Diameter, outside, inches 6 Number of rings 2 3 Each . .35 .50 8 .45 C 8 4 .70 10 .60 D 10 5 1.00 12 .70 E 12 6 1.30 13966. TRIPODS, iron, with sheet iron chimney, for protecting burner flame from drafts. Height over all, 9 inches. Diameter, inches 3V> 5 6 Each . .90 L10 1.50 506 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 13990. Nos. 13972-78. No. 13980. No. 13992. No. 14006. No. 14008. No. H010. No. 14012. No. 14022. 13972. TROUGH, Pneumatic, of japanned tin with sliding shelf and overflow; students' size, 41/!>x61/£xlO inches ?°-70 13974. TROUGH, Pneumatic, of heavy japanned tin with sliding shelf and overflow, 6x11x16 inches 1.60 13978. TROUGH, Pneumatic, heavy galvanized iron with sliding shelf and overflow, 5x9x12 inches. 1.00 13980. SUPPORT, Beehive, for use with Nos. 13972 to 13978, for supporting the inverted receptacle in collecting gases; of zinc, 3 inches in diameter .40 TROWEL, 6 inch cold rolled steel blade, with malleable iron shank firmly riveted on and wood .12 13988. 13990. 13992. handle TROWEL, best quality, with 6 inch blade made of one solid piece of steel, with wood handle. Will outwear all others .55 TROWEL, Transplanting or Collecting, with narrow and deeply curved blade 6 inches long, and wood handle. Useful with the collecting case or as a transplanter, dibber, or weed digger .15 T SQUARE, see Drawing Instruments. 14000. 14002, 14006. 14008. 14010. 14012. 14016. 14020. 14022. TUBES, ALL KINDS TUBES, Absorption, see Absorption Tubes. TUBE, Air Thermometer, see Air Thermometer Tubes. TUBES, Arsenic, see Arsenic Tubes. TUBES, Calcium Chloride, see Calcium Chloride Tubes. TUBES, Centrifuge, see Centrifuge Accessories. TUBES, Color, see Colorimetric Apparatus. TUBES, Combustion, see Combustion Tubes. TUBES, Connecting, Brass. Approximate length of arms, 1% inches. No Diameter, outside, inches Diameter, inside, approx., inches TUBES, T shape TUBES, Y shape TUBES, Connecting, Glass. No Diameter, outside, mm Diameter, inside, mm Approx. length of arms, mm TUBES, T shape TUBES, U shape TUBES, Y shape A 5 3 50 .10 .10 .10 B 7 5 50 .12 .12 .12 9ie .40 .40 C 8 6 60 .20 .20 .20 We .60 .60 D 10 8 75 .25 .25 .25 C V, K« .70 .70 E 12 10 100 .40 .40 .40 TUBE, Connecting, Glass, T shape, with two stop-coeks. Diameter outside, 7 mm; inside, 5 mm. 3.00 TUBE, Connecting, Lead, Y shape. Diameter outside, 8 mm; inside, 5 mm. Length of arms, about 1% inches .30 TUBE, Connecting, Hard Rubber, Y shape. Diameter outside, 8 mm; inside, 5 mm. Length of arms, about 1 inch .15 TUBE, Connecting, Reducer, Brass, for connecting ~/16 inch to %2 inch tubing. Without threads. .25 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 507 No. F3355. No. 14030. No. 3102. TUBES, Culture, see Test Tubes. TUBES, Drying, see Calcium Chloride Tubes. TUBES, Fermentation, see Fermentation Tubes. TUBES, Filtering, see Filter Tubes. TUBES, Fractional Distillation, see Distilling Tubes. TUBES, Fused Silica, see Combustion Tubes. TUBES, Geissler, see Catalog F of Physical Apparatus. TUBE, Hortvet, see Sugar Analysis Apparatus. TUBES, Melting Point, see Melting Point Tubes. TUBES, Phosphorus, see Centrifuge Accessories. TUBES, Potato Culture, see Test Tubes. TUBES, Pyrometer, see Pyrometer Protection Tubes. TUBES, Transparent Quartz, see Combustion Tubes. TUBES, SoU Sampling, see Soil Analysis Apparatus. TUBES, Specimen, see Test Tubes. TUBES, Test, see Test Tubes. TUBES, Vacuum or Dewar, see Vacuum Tubes. TUBES, Water Analysis Color, sec Color Tubes. TUBES, X Ray, demonstration form, see Catalog F of Physical Apparatus. TUBING, Flexible Metallic, see Rubber Tubing. TUBING, Rubber, see Rubber Tubing. TUBING, SILICA, see Silica Tubing. TUMBLERS, Glass, -with lip, see Beakers. F3355. TUMBLERS, Glass, Heavy, capacity, about 250 cc; diameter at top, 60 to 65 mm. each $0.06 per dozen .60 TUMBLERS, Jelly, see Jars. 14030. TURBIDIMETER, Jackson's, for determining sulphates in water; consisting of a graduated tube 22 cm long, with metal ease to exclude the light, and a support for tube and candle . . . 14.00 14031. CANDLES for use with No. 14030. . per dozen 3.00 14032. GRADUATED TUBES, extra, for No. 14030. No Length, cm Each . A 22 2.50 B 75 5.00 14033. BRASS EXTENSION for use with No. 14030 when using long graduated tubes 4.50 3102. TURBIDIMETER, United States Geological Survey Standard, inade of aluminum, 8 inches long, graduated in parts per million. To one end is attached a tape 4 feet long, similarly graduated. Into the other end is fastened a nickel-plated brass screw eye containing a piece of rolled platinum wire to be viewed. The depth of its disappearance to the eye indicates the turbidity. Complete in case. (See Bulletin No. 151 of the United States Geological Survey) 7.50 TWINE, Asbestos, see No. 312. 14038. TWINE, Cotton, 3-ply Per ball .16 14040. TWINE, Linen, No. 9, white Per ball .45 508 CENTRAL SCIENTIFIC CO., CHICAGO, TT. 8. A. No. 14060. No. 14062. No. 14064. No. 14070. No. 14071. No. 14072. No. 14075. No. 14074. No. 10502. No. 156 No. 14086. URINE ANALYSIS APPARATUS 14060. ALBUMINOMETER, Esbach's, for the quantitative determination of albumin in urine; gradu- ated to read grams of albumin per liter of urine. Complete with directions $0.65 14062. ALBUMINOMETER, Esbach's, with pointed bottom, for testing small quantities, on foot 1.00 14064. ALBUMOSCOPE (Horismascope), for the detection of albumin in urine ith nitric acid. With this instrument the nitric acid comes in contact with the urine in full strength, thus rendering the test much more delicate than ordinarily, 1/60 per cent, of albumin being detectible. Com- plete with directions for use 1.25 14066. FEHLING'S SOLUTION, tablet form for use in Urine Analysis, sufficient to make one ounce of solution 25 FOLIN'S APPARATUS FOR THE DETERMINATION OF AMMONIA, TOTAL NITROGEN AND UREA IN URINE (See Journal of Biological Chemistry, Vol. XI, No. 5. for June 1912.). 14070. AMMONIA ABSORPTION TUBE, small, with perforated end, 265 x8 mm 20 14071. AMMONIA TRAP, Glass 50 14072. CONDENSER TUBE, for urea, 250 x 15 mm 30 14074. FUME ABSORPTION TUBE, straight, for bending to desired shape in the laboratory. . . .60 14075. CONNECTING TUBE or Manifold for use with No. 14074 Absorption Tubes. No A B C Number of arms 4 5 6 Each 90 1.00 1.20 10502. OSTWALB PIPETTES, graduated to deliver exact amounts at 20°C. Capacity, cc 1 2 Each 1.00 1.00 13364E. TEST TUBE, non-corrosive glass, 200 x 25 mm 15 14078. TEMPERATURE BULB, filled with mercury chloride-iodide 40 156. AMMONIA ABSORPTION APPARATUS, Folin's, complete with cylinder, two hole rubber stop- per, drying tube, Folin Absorption Tube No. 157 and bottle 3.25 157. AMMONIA ABSORPTION TUBE only of No. 156 1.60 14086. PURINOMETER, Hall's, for the riuan'titative determination of purin nitrogen in urine. With glass stop-cock, glass stopper and wooden base, graduated from 0 to 100 cc in 1 cc 10.00 14087. TEST SOLUTION No. 1, for use with No. 14086 . . .per 6 oz. bottle .50 14088. TEST SOLUTION No. 2, for use with No. 14086 per 6 oz. bottle .55 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 509 No. 14098. No. 14102. No. 14116. No. 14120. No. 14122. No. 14126. 14092. SACCHAEOMETER, Einhorn's Fermentation, for the estimation of sugar in urine. Consists of a graduated fermentation tube on foot and a graduated test tube. The percentage of sugar is read directly on the tube. $0.75 14093. GRADUATED TEST TUBE only for No. 14092 30 14096. SACCHAROMETER, Einhorn's Fermentation, set of two, one for the urine under examination, the other for normal urine to which glucose has been added to test the efficiency of the yeast used. With graduated test tube 2.00 14098. SACCHAROMETER, Lohnstein's for the accurate determination of sugar in diluted urine. Com- plete with graduated test tube, in case -with directions for use 2.50 14102. UREA APPARATUS, Folin, for the determination of urea in urine, consisting of an Erlenmeyer flask with one-hole rubber stopper, and special urea bulb 1-75 14103. UREA BULB only for No. 14102 1.20 14106. UREA APPARATUS, Van Slyke-Cullen, for the determination of urea in blood and urine. The apparatus consists of 9 heavy walled glass test tubes fitted with two-hole rubber stoppers, through which are inserted Folin Ammonia Absorption Tubes and connecting tubes, mounted in a heavy wooden block. Complete with rubber connecting tube, brass Filter Pump No. 5476A, Coupling No. 5480A, and a 5 gram bottle of urease. (See Journal of Biological Chemistry, Vol. XIX, page 211, 1914) : 11.00 14107. FOLIN AMMONIA TUBES only of No. 14106 each .55 14108. CONNECTING TUBES only of No. 14106 each .20 14109. TEST TUBES only of No. 14106 each .35 14110. UREASE for No. 14106 per 5 gram bottle .75 14114. UREOMETER, Doremus', for the rapid quantitative determination of urea in urine by the hypo'- brornate method. Consists of a graduated pipette and a fermentation tube graduated to read to 1/10 per cent. Complete with directions for use 1-00 1411fi. UREOMETER, Doremus', same as No. 14114, on glass foot 1.00 14117. DROPPING PIPtiTTE only for Nos. 14114 and 14116, graduated at 1 cc 15 5290. SUPPORT, Hardwood, with brass clips, for No. 14114 1.00 14120. UREOMETER, Doremus'-Hinds, with glass stop-cock and side tube graduated in tenths of a cc for delivering accurate amounts of urine without permitting the escape of gas from the bulb. On glass foot 3.60 14122. UREOMETER, Squibb's, for the approximate determination of urea in urine by displacement. Complete with 50 cc bottle of reagent, vials, graduated pipette, graduated cylinder, with direc- tions for use 3.50 14126. URICOMETER, Ruhemann, for estimating directly the amount of uric acid in urine in parts per 1000 5.00 510 CENTKAL SCIENTIFIC CO., CHICAGO, IT. S. A. No. 14150. No. 14156. No. 14164. 14130. TJRINOMETER, Squibb's, for the determination of the specific gravity of urine. Length, 5 inches. Graduated from 1.000 to 1.060. Guaranteed accurate for temperatures of 77° F. In case, with fluted cylinder and directions, without thermometer $0.90 14132. TJRINOMETER, Squibb's. Same as No. 14130, but with thermometer in float body, with scale of corrections for temperature 4.50 14133. CYLINDER only of Nos. 14130 and 14132 35 14136. TJRINOMETER, small size, for testing 1 fluid-ounce or 30 cc samples. With specific gravity scale 1.005 to 1.035 in 0.001 graduations, with spines on body to prevent clinging to sides of jar. Complete with test jar graduated in % ounce and 5 ce divisions with lip 1.80 14138. TJRINOMETER, small size, same as No. 14136 with separate thermometer showing corrections for temperature 3.00 URINE SEDIMENT GLASSES, see Test Glasses. 14150. VACUUM BOTTLES, for keeping hot liquids hot and cold liquids cold, with re-enforced vacuum chamber. Supplied with large size drinking cup, securely fastened to the case, preventing leak- age of the contents through loosening the eork. Finished in red japan, with nickeled top and base. No A B Capacity pint quart Each 1-V5 2.75 14151. GLASS BOTTLES only for No. 14150, for replacement. No A B Each 1-25 2.00 VACUUM PUMPS, see Pumps, Air. VACUUM TUBES, Dewar's, double walled, for liquid air experiments. No A B C D Length, outside, cm 10 20 30 35 Diameter, outside, cm 4.5 5.5 6.5 14154. TUBES, Silvered 4.00 5.40 11.00 19.50 14156. TUBES, Unsilvered 3.30 4.50 10.00 18.00 VALENCE BLOCKS, see Models. VAPOR DENSITY APPARATUS 14164. VAPOR DENSITY APPARATUS, Dumas, complete with kettle and bulb support, but without thermometer or bulbs 15.00 856. DUMAS BULBS for No. 14164, capacity about 200 cc each .35 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 511 No. 14170. No. 14178. No. 14188. No. 14192. 14170. VAPOR DENSITY APPARATUS, Victor Meyer, complete with outer jacket of glass, 25 inches long and 1% inches in diameter, inner tube 33 inches long, without bottle for containing the liquid to be tested $2.25 14171. BOTTLES, small, glass stoppered, for use with No. 14170 Each .30 Per dozen 3.30 14172. INNER TUBE only of No. 14170, with side arm 1.10 14173. OUTER JACKET only of No. 14170, of glass 1.25 14174. OUTER JACKET only of No. 14170, of copper, according to McCoy 6.00 ' 14178. VAPOR DENSITY APPARATUS, Weiser's Modification of Victor Meyer's, designed to shorten the apparatus while retaining all the desirable features of the original. Length of outer jacket, 32 cm; diameter of outer jacket, 6 cm; capacity of vaporization bulb, about 125 ee. Complete as described with 2 glass stoppered bottles. (See Journal of Physical Chemistry, Vol. XX, No. 6, page 532, for June 1916) 2.25 14179. INNER TUBE only of No. 14178 1.10 14180. OUTER JACKET only of No. 14178 1.25 VASCULUM, see Botanical Apparatus. VERNIER CALIPERS, see Calipers. VIALS, see Bottles. VISCOSITY PIPETTE, see Physical Chemistry Apparatus. VTSCOSIMETERS, see Oil Testing Apparatus. 14188. VISES, Anvil, adjustable jaws, strongly constructed. Base is drilled to fasten rigidly to bench bv screws. "No A B C Width of opening, inches 3 5 Width of jaw, inches 2% 3% 4 Weight, pounds 9 25 35 Each 6.50 8.10 10.00 14190. VISES, Anvil with Clamp. Provided also with a steel base drilled to fasten rigidly to bench by screws. No A B Width of opening, inches 2^ 3% Width of jaw, inches 2*4 2% Weight, pounds 5% Each 3.00 4.20 14192. VISES, Anvil with Clamp, Small. Very convenient for laboratory use. No A B Width of opening, inches 1% 1% Width of jaw, inches !% Weight, pounds Each . 1-20 1.80 512 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 14196. No. 14224. No. 14228. No. 14230. No. 14236. 14196. VISE, Hand, with parallel jaws. Very convenient and useful. Made from drop forgings, with the faces of the jaws scored and case hardened. The faces of the jaws are 1%0 inches long, % inch wide; jaws open 1% inches; whole tool 4% inches long. Black finish $2.00 VOLTMETERS, see Electrical Instruments. VOLUME OF LOAF APPARATUS, see Flour Testing Apparatus. WARMING TABLE, see Nos. 8862, 8864, and 8936. WARM STAGES, see Microscope Accessories. 14214. WASHER CUTTER. A strong, well made, useful device for cutting washers of diameter from % in. to 5% in. Provided with removable blade adjustable as to length of cutting edge as well as position. These blades can easily be eemoved for sharpening or replaced when they wear out. Nicely polished and attractive in appearance 2.25 WASHING BOTTLES, see Bottles. WASHING BOTTLES for Gas, see Gas Washing Bottles. WASHING PANS for Gold, see Pans. 14220. WASTE CAN, Galvanized, 14x14% inches; capacity, 9% gallons; with seamless cover fitting over outside 3.00 WASTE JARS, see Jars. WASTE PAIL, see Pails. 14224. WATCH GLASSES, well annealed, with edgos smoothly ground. Diameter, inches... 1% 2 2'/i 3 3% 4 4% 5 67 8 Per dozen 40 .50 .60 .70 .90 1.00 1.20 1.30 1.60 1.80 2.00 14226. WATCH GLASSES, in Pairs, with edges ground to fit accurately together, for use with Clamps Nos. 2902-4. Diameter, inches 2 Per pair 20 14228. WATCH GLASSES, in Pairs, same as No. 14226, with Clamp No. 2902. Diameter, inches 2 Per pair with, clamp 32 14230. WATCH GLASSES, in Pairs, same as No. 14226, with Clamp No. 2904. Diameter, inches 2 Per pair with clamp 30 WATCH GLASS CLAMPS, see Clamps. 824. WATCH GLASSES, Counterpoised, for use on balance pans. Diameter, mm 50 62 Per pair 90 1.00 WATCH GLASSES, Embryological, see Dishes, Staining. 14236. WATCH GLASSES, Syracuse, plain; outside diameter 65 mm; inside diameter, 50 mm. Grooved to facilitate stacking Per dozen .70 14238. WATCH GLASSES, Syracuse, same as No. 14236, with beveled surface ground for writing. Per dozen 1.00 14244. WATCH SPRINGS, for burning in oxygen Per dozen .20 2V> .25 2V> .37 2% .35 75 1.25 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 513 O. 14258. No. 14268. WATER BATHS 14250. WATER BATHS, polished copper, tin lined, with concentric copper rings and cover, handles and steam escape. Diameter, inches 4 5 6 8 10 Number of rings 3 4 5 6 8 Each $1.30 1.45 2.00 3.20 5.00 14252. WATER BATHS, for Steam Hjat, same as No. 14250 with steam valve and waste pipe. Diameter, inches 6 8 10 Each 5.40 6.60 9.10 14254. WATER BATHS, polished copper, same as No. 14250, with constant water level. Diameter, inches 4 5 6 8 10 Number of rings 3 4 5 6 8 Each 1.80 2.00 2.25 2.70 5.00 14258. WATER BATH, polished copper, with 5 concentric rings and water level regulator. Diameter, 6 inches; depth, 4 inches. Complete with iron tripod 9 inches high 6.00 14262. WATER BATHS, seamless polished copper, tin lined, with copper concentric rings and cover, steam escape, handles, flange for tripod, and perforated plate for test tubes up to % inch in diameter. Diameter, inches 6 8 With plate for, tubes 12 19 Each 4.50 6.50 14264. WATER BATHS, same as No. 14262, with tripod and copper rack for test tubes up to % inch in diameter. Diameter, inches 6 8 For test tubes 12 19 Each 5.00 7.00 14266. WATER BATH, for dissolving steel samples, of polished copper, tin lined, with zinc tray for 18 test tubes 6 x % inch. Diameter, 6 inches; Height, 7 inches 5.00 14268. WATER BATH, for dissolving steel samples, square form, 7% x 7^ x 6M> inches high, of pol- ished copper, tin lined, with tray for 25 test tubes 8 x % inch. Mounted on heavy iron sup- port '. 7.50 514 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. -I? Nos. 14290-1. No. 14202. 14272. 14274. 14276. 14278. 14282. 14288. 14290. 14291. 14292. WATER BATH, rectangular form, with 4 openings 5 inches in diameter, with concentric rings, and cover, stop-cock for draining, constant water level regulator, tubulatures for thermometer and thermo-regulator, and an extra sheet iron bottom, mounted on heavy iron support. Dimen- sions, 14 inches square by 5 inches deep $21.00 WATER BATH, same as No. 14272, but with coil for steam heat 25.00 WATER BATH, of similar construction to No. 14272, but with 7 openings, 3 of 6 inches diameter, and 4 of 4 inches. Dimensions, 23 x 13 ^ x 5 inches deep 27.50 WATER BATH, same as No. 14276, but with coil for steam heat 31.50 WATER BATH, Electrically Heated, with cup of seamless copper nickel-plated and concentric rings. Provided with self-enclosed heater, and with automatic cut-out, which shuts off the current if the vessel boils dry. It will boil 1 quart of water in 6 minutes. Diameter, 4 inches; capacity, 1 quart; power consumption, 550 watts. Complete with 6 feet of silk covered cord and attachment plug for connection to any 110 volt lamp socket 22.00 WATER BATH, Agar Melting, gas heated, for keeping agar liquefied for inoculation previous to pouring into Petri dishes. Made of heavy copper tinned inside, with lid which slopes from the center to all four sides preventing moisture from dripping into the tubes. Troughs are ar- ranged along the sides to carry off the condensed moisture. Provided with tubulations for ther- mometer and thermo-regulator. Complete with six tinned wire test tube baskets, S1^ x 3% x6 inches, and with cast iron support stand 8% inches high. Height over all, 18 inches; length, 11% inches; width, 7% inches. Without burner 35.00 WATER BATH, Alsop's, as used in tanning and leather laboratories. Of heavy copper with con- denser at top which may be used to furnish distilled water. Length inside, 25 inches; width inside, 20 inches; capacity, 60 crystallizing dishes 80 mm in diameter. For gas heat.. 200.00 WATER BATH, Alsop's, same as No. 14290, but .with coil for heating by steam 215.00 WATER BATH, Blair's, with rack for 10 test tubes; as used in iron analysis. Of polished cop- per, 7 inches in diameter 4.75 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 513 No. 14296. 14296. WATER BATH, DeKhotinsky, Electrically Heated, intended to replace the ordinary Bunscn burner heated bath, in laboratories where electric current is available. The bath consists of a copper container \<, mm (0.02 inch) thick, spun in one piece and nickel-plated. It is lagged with 25 mm (1 inch) of magnesia-asbestos and protected outside by red fiber. The bath is attached to an enameled cast-iron base, fitted with a nickel-plated supporting rod, to which laboratory clamps may be attached for the support of flasks, condensers, etc. The top of the bath is fitted with a set of six porcelain rings to accommodate the different sizes of flasks or evaporating dishes. Capacity of bath 1000 cc. Height (without stand) 12.5 cm. Volume of container 1400 cc. Height (inside) 9.5 cm. Diameter (outside) 19 cm. Height (with stand) 18.5 cm. Diameter (inside) 14 cm. Weight lOlbs. Four electric heating units of 44 watts each are used to supply heat to the bath. These units may be added one by one, by means of the switch which constitutes a part of the bath, and the desired temperature thus secured. The bath has a constant water level attachment, by means of which the water level may be kept constant at any point within a range of 25 mm (1 inch). The regu- larity of the water level is 1 mm. The following table shows the capacity of the bath: Number of heating units 3 2 1 Total energy consumed, watts 132 88 44 Temperature maintained, C 100° 95° 72° With four heating units (176 watts) the boiling is, of course, more rapid. As the heating units are inserted in brass tubes placed permanently inside of the bath, 20 mm from the bottom, their heating value come? to 99 per cent, of the theoretical expenditure of energy. Placed as they are, the heating units are absolutely protected from accidental injury. To replace these units takes no more time or skill than to replace an incandescent lamp in its socket. This bath operates on either a direct or alternating current, and may be attached to any Edison socket. Complete as describe.!, without glassware. No A E For volts 110 220 Each $27.50 30.00 HEATING UNITS, extra, for No. 14296, 44 watts each. No 7526A 7527A For volts 110 220 Each 1.00 1.25 rie CENTKAL SCIENTIFIC CO., CHICAGO, U. S. A. 14300. 14301. 14302. 14303. WATER BATH, DeKhotinsky, Electrically Heated and Regulated (Patented), intended for use in modern chemical, physical and bacteriological laboratories, where constant temperature is imperative. It consists of a copper container % mm (1/32 inch) in thickness, heavily nickel- plated inside and out, lagged with 25 mm (1 inch) magnesia-asbestos (magnesia 85%), and pro- tected outside by a sheet of Russia iron. The bath is attached to an enameled cast-iron base, supplied with three nickel-plated rods, to which may be attached laboratory clamps for sup- porting flasks, etc. Each bath is fitted with four electric heating units, three of which may conveniently be added one by one, by means of the switch constituting part of the bath. The fourth unit is electrically connected to the relay, which is automatically operated by a thermo- regulator. The thermo-regulator consists of a solid drawn-steel tube, brass covered, nickel-plated, filled with mercury, with a platinum contact attached to a regulating cap, by means of which the bath can be regulated and set to the desired temperature, ranging from the temperature of the surrounding atmosphere to the boiling point of water. Should a temperature higher than the boiling point be needed, the water may be replaced by Crisco, which can be used up to a tem- perature of 165° C., or even higher. For temperatures within 2 degrees of room temperature and lower, No. 14306 Cooling Coil must be used. With this bath, when provided with a No. 12864 High Speed Turbine Stirrer, the temperature can be held constant to 1/10 degree C., over long periods of time. A constant water level attachment is furnished with each bath, by means of which the water level can be regulated within a range of 35 mm (IVi inch) and maintained within 1 mm of the level at which it is set. This bath has a very good natural circulation, as heat is supplied in- side the bath 25 mm from the bottom. When experiments or research demand a more vigorous circulation and regulation closer than 1/10° C., a small High Speed Turbine Stirrer No. 12864 can be attached to the bath. This stirrer of 18 mm diameter takes water from the bottom of the bath at the rate of five liters per minute, and delivers it at the top with an energy expenditure in the motor of 15 watts. On the shaft of the circulation turbine is an extra pulley to connect with the glass stirrer in the flask. Complete with water bath, four heating units, relay, thermo- regulator, constant water-level device, support rods, five feet of cord and attachment plug. If uniformity of temperature throughout bath is desired, stirrer should be included. No A Capacity, liters 9.3 Diameter inside, cm 25 Available height inside, cm 19 For 110 volts A. C $75.00 For 220 volts A. C 77.50 For 110 volts D. C 72.50 For 220 volts D. C 75.00 Note: — In ordering state mean temperature desired, so that heating units of correct wattage may be furnished. B 18.25 30.5 25 98.50 101.00 96.00 98.50 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 517 No. 14312. No. 14316. A A A A 22 5 Me 6.00 B B 10.00 c B 30 8 fo 7.00 14306. COOLING COLL, for use in Water Baths No. 14300, of copper nickel-plated. No For Bath No Each HEATING UNITS, extra, for No. 14300, see Nos. 7526-7. 12864. STIRRERS, High Speed Turbine, for use with Nos. 14300-3. 2*o For Nos. 14300-3 Diameter, mm Capacity, liters per minute Power required to operate, h. p Each 14310. WATER BATH, Griffin's, for hot filtration and evaporation. Of heavy copper, tin lined, with two 5 inch openings in the top. One opening is fitted with a copper funnel, the other is pro- vided with four concentric copper rings. Complete with constant water level regulator and tubulatures for thermometer and thermo-regulator, mounted on support with extra sheet iron bottom and detachable legs. Dimensions, 13 x 7 x 5 inches high 13.00 14312. WATER BATH, Hofmann, of polished copper, tin lined, with a set of concentric rings and a plate with five different sized openings, each with cover. Diameter at top, 8 inches; depth, 5 inches; with constant water level and handles 15.50 WATER BATH, Victor Meyer's, funnel shape, of polished copper, tin lined, w.th concentric rings, cover and constant water level, with tripod 8 inches high. Diameter, 6 inches 5.50 WATER BATH, Wassermann, with 12 copper racks, each of which holds 12 tubes 4x % inches. These racks are so aranged that they can be lifted out of the bath by the two handles attached to each of the racks, and are also supplied with a center division to allow shaking of the test tubes without danger of dropping. The bath is made of heavy polished copper, with a per- forated bottom, thereby providing for a large volume of water. Complete with thermometer, glass thermo-regulator for controlling the temperature, and 12 copper racks. Height over all, 13% inches; length, 12% inches; width, 12% inches; depth, 5% inches. With sheet iron base 8 inches high. Without burner 35.0C 14323. SUPPORTS, Test Tube, only for No. 14322, for tubes 4 x % inches. No A B C For tubes 12 24 40 Each 1.30 2.00 2.60 TEST TUBES, Wassermann, see No. 13390. 14316. 14322. 518 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Nos. 14326-8. PATfAPPLD. FOB No. 14332. 14326. WATER BATH, Wassermann, round form, of copper tin lined, with copper rack for holding 28 test tubes 3 x % inches, and with tubulatures for thermometer and thermo-regulator, mounted on sheet iron base, 4 inches high. Diameter, 6 inches; depth, 4 inches. Without heater or thermo-regulator $12.00 14328. ELECTRIC HEATER AND THERMOSTAT, Combined, for No. 14326. Consisting of a heating disk 5 inches in diameter by % inch in thickness, mounted with an adjustable pencil-type electro-thermostat 6 inches long and % inch in diametor, with a pilot lamp to indicate when the current is on or off. This outfit can be used for heating and regulation in any water bath whose capacity does not exceed 2 quarts with the depth of the water not less than 2 inches. It can be set for any temperature between 35° and 60° C., but the best results are obtained by having it set at the factory for a fixed temperature and not readjusting it. Shipping weight, 3 pounds. Complete with 6 feet of flexible cord and an attachment plug for connection to any 110 volt lamp socket. Without water bath 25.00 14332. WATER BATH, Wassermann, DeKhotinsky Electrically Heated and Regulated, for precision work in incubation, inactivation, the study of thermal death-points, etc. This bath is a special type of the DeKhotinsky Electrically Heated and Begulated Water Baths No. 14300, of a shape and design adapted especially for bacteriological and clinical work. It will accommodate special supports for 48 Wassermann tubes, and trays for 18 Vaccine tubes. It is of the same construc- tion as No. 14300, and is provided with the same system of heating and regulation, for control of temperature to 1/10° C. In order to secure this degree of precision, Stirrer No. 12864A must be included in the equipment. Diameter of the bath, 10 inches; available height, 8 inches. Complete with four standard heating units, mercury thermo-regulator, sensitive iron-clad re- lay, constant water level device, three-point switch, three support rods for clamping devices in the bath, and five feet of cord and attachment plug, but without stirrer, test tube supports, or cooling coil. No A B C D A. C. D. C. For volts 110 220 110 220 Each 75.00 77.50 72.50 75.00 14333. COOLING COIL, for use with No. 14332 when it is necessary to maintain the temperature within 2 degrees of room temperature or lower 8.00 HEATING UNITS, extra, for No. 14332, 115 watts each. No 7526D 7527D For volts 110 220 Each 1.00 1.25 • 12864A. STIRRER, High Speed Turbine, for use with No. 14332 in order to hold the temperature constant to 1/10 degree C. It clamps on one of the support rods, and has two pulleys at the top, one for belting to a motor, the other for operating a stirring rod in flasks or other vessels in the bath. Capacity, 5 liters per minute; power required to operate, ^g h- P ^.00 CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. 519 No. 13172. No. 13174. No. 14340. No. 14336. No. 14337. 13172. SUPPORT for use with Xo. 14332, for 18 Vaccine tubes *5.00 13174. SUPPORT for use with Xo. 14332, for 48 Wassermann tubes 4.50 14336. WATER BATH, Wasserman, Schultz, Electrically Heated and Regulated, for routine work not requiring such close regulation as is obtained with Xo. 14332. The bath is made of heavy cop- per, tinned on the inside, and covered on the outside with thick insulating material. The heat- ing units are wound on lavito cores, and are placed in metal tubes at the bottom of the bath, these tubes being entirely surrounded by water. Provisions are made, so that the units can be easily replaced in case of accidental injury. A snap switch is provided, which controls one- half of the heating units, the others being permanently connected in the circuit. The bath may be used at a temperature of 56° C. as an inactivating bath, or at 37.5° C. for incubation pur- poses. Begulation of the temperature is effected by a removable Pencil Type Bimetallic Thermostat, placed in a metal tube at the bottom of the bath near the heating units. A pilot lamp is furnished for indicating when the current is on or off. For 110 volts A. C. or D. C. Complete with test tube racks, thermometsr, 3x% inch test tubes, and 7 feet of connecting cord and attachment plug. Xo A B Dimensions, inches 9x4^x5 9x9x5 Xumber of racks 1 2 Capacity, tubes 48 96 Current consumption, amperes '..... 1% 2 Each 42.50 55.00 In ordering, kindly specify whether the thermostat should be set for 37.5° or 56° C. 14337. TEST TUBE RACK only of Xo. 14336, holding 48 3x% inch test tubes. Made from nickel- plated brass with adjustable supports for suspension in bath, and furnished with three shelves as shown in illustration. Dimensions of rack: 8%x3%x2% inches high. Height O"er all, 8 inches. Without test tubes 5.50 14340. WATER BATH, Whipple's, for melting gelatine. Of heavy copper, tinned inside, with rack to hold 48 test tubes up to % inch in diameter. An incandescent lamp may be used to heat the bath to the required temperature. Diameter of bath, 12 inches; depth, 5 inches. Without lamp, lamp socket or cord • 17.50 520 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. No. 14366. No. 14370. No. 14359. 14344. WATER BATH, Wiley Patented, designed to generate steam quickly with small gas consump- tion. Of heavy copper with replaceable water cup of spun copper 3% inches in diameter, with 12 openings S1/^ inches and 2 openings 5% inches in diameter, with concentric copper rings and constant water level regulator, mounted on substantial angle iron support. Dimensions of top, 25x141^ inches; depth on outside edge, 2 inches; depth in center, 4 inches; capacity to water inlet, 250 cc. Can be operated easily by one ordinary Bunsen ' urner $50.00 14345. EXTRA WATER CUPS for No. 14344 each 1.15 WATER EXAMINATION APPARATUS COLOR TUBES, see Nos. 3014 to 3032. 3010. HEHNER'S CYLINDERS for the estimation of iron in water, consisting of two graduated glass tubes of same size and graduation, with stop-cocks per pair 6.00 HYDROTIMETERS for hardness of water, see No. 7800. NESSLER JARS, soe Color Comparison Tubes. SEDGWICK-RAFTER APPARATUS, for Microscopical Examination of Water. See ' ' The Microscopy of Drinking Water," by Geo. C. Whipple. 14352. SEDGWICK-RAFTER FUNNEL, graduated, with attachment and rubber stopper 3.25 14353. SEDGWICK-RAFTER FUNNEL, plain, with attachment and rubber stopper 1.50 14354. BERKSHIRE SAND per pound .15 14355. BOLTING CLOTH DISKS per dozen .25 14356. SUPPORT for funnel 1-75 14357. COUNTING CELL 3 50 14358. COVER SLIP 30 14359. EYEPIECE MICROMETER 3.50 14360. PIPETTES, a set of two, one each 1 ce and 5 cc per set .35 14361. GRADUATED FLASK, 25 cc ' 50 MICROSCOPE, see general heading Microscopes. WATER HEATERS, see Heaters. 14366. WATER SAMPLE CASE, consisting of a well made wooden case with hinges, hasp and handle; with separate compartments for one 5 pint and one 4 ounce glass stoppered bottle. Excellent for obtaining samples of drinking water for analysis by health departments. Complete with bottles and container for small bottle 5.00 14370 WATER TESTING APPARATUS, for the determination of ammonia in water, as used by the De- partment of Health of New York City, consisting of a metal condenser with block tin condenser tube and support, eight Nessler cylinders graduated at 50 and 100 cc in revolving support, flask, burner and support for same. .". 25.00 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 521 14376. WAX, Bees', Genuine, unbleached, in cakes Per Ib. $1.00 14377. WAX, Bees', Imitation (ceresin), yellow Per Ib. .40 14378 WAX, Sealing, express, red, four sticks to the pound Per Ib. .55 14380. WAX, Universal, for use in t!ie laboratory wherever a plastic yet firmly adhesive cemeut is needed. In 4-ounce jars Per jar .30 14382. WAX TAPEES, for burning in oxygen, etc., in boxes of 12 P-jr box .10 14390. WEATHER FORECAST CHART," or Key to Barometer Reading, and Chart for Aneroid Bar- ometer, by J. Benj. F. Rawson, late of the Weather Bureau. This chart is intended as an aid in the intelligent interpretation of barometer readings and in forecasting weather for twenty- four hours. This chart will be found quite accurate and most useful in any science labora- tory. With full directions -50 14392. "WEATHER AND WEATHER INSTRUMENTS. " This book describes the mechanism of the many instruments and in addition gives in concrete and simplified form the practical uses of the different instruments. The tables of classified data recommend it particularly to teachers. Pasteboard covers -50 14393. "WEATHER AND WEATHER INSTRUMENTS," same as above, cloth covers 1.10 14396. "PRACTICAL HINTS for Amatsur Weather Forcasters." Information on the care and ex- posure of barometers. 24 pages, illustrated -10 WEIGHING BOTTLES, see Bottles. WIRE, ALL KINDS 14410. WIRE, Aluminum, bare. B. & 8. No 14 16 18 20 22 24 26 27 28 30 Approx. diameter, inches.. .064 .051 .040 .032 .025 .020 .016 .014 .013 .010 Per 4 oz. spool 1.50 1.80 2.10 2.40 3.75 Per 1 Ib spool 2.45 2.70 2.85 3.30 3.90 5.10 14412. WIRE, Brass Spring, on 4-ounce spools. Washburn & Moen No.. 16 18 20 22 24 26 27 28 30 32 34 36 Approx. diam., inches.. .063 .047 .035 .028 .023 .018 .017 .016 .014 .013 .010 .009 Approx. feet per spool. 20 33 68 108 170 270 340 430 550 862 2270 3520 Per spool 40 .40 .40 .45 .55 .60 .66 .66 .70 .80 1.10 1.80 14416. WIRE, Copper, Annunciator Wire, double cotton covered and paraffined. Orders not accepted for less than 1 Ib. B. & 8. No 16 18 20 22 24 Approx. feet per pound 106 157 230 350 550 Per pound 1.45 1.50 1.55 1.65 1.70 14418. WIRE, Copper, Lamp Cord, composed of fine wires insulated with rubber and braided cotton; two conductors twisted. B. & S. No 16 18 20 22 Per foot 10 .05 .05 .05 WIRE, Copper, Magnet Wire. B. & 8. No... 10 12 14 16 18 20 22 24 26 27 28 30 32 34 36 40 Approx. diam., inches 102 .081 .064 .051 .040 .032 .025 .020 .016 .014 .013 .010 .008 .006 .005 .003 14422. BARE WIRE. Per 4 oz. spooL 65 .65 .65 .65 .65 .70 .751.00 Per 8 oz. spool 95 .951.001.001.051.101.20 .... Per 1 Ib. spooL 1.40 1.40 1.40 1.45 1.45 1.45 1.50 1.55 1.55 1.60 1.60 1.65 1.70 1.80 1.90 .... 14423. D. C. C. WIRE. Per4oz. spooL 75 .80 .90 .95 1.05 1.10 1.15 1.30 1.50 1.70 2,00 4.35 Per 8 oz. spool 1.20 1.25 1.45 1.65 1.80 1.90 1.95 2.30 2.65 3.05 3.65 .... Per 1 Ib. spool. 1.60 1.65 1.70 1.80 1.90 2.15 2.45 2.70 3.00 3.25 3.40 3.90 4.60 5.50 6.70 .... 14424. D. S. C. WIRE. Per4oz. spooL 95 1.05 1.25 1.40 1.50 1.60 1.95 2.45 3.25 3.95 7.90 Per 8 oz. spool 1.40 1.60 1.80 2.15 2.45 2.70 2.90 3.60 4.55 6.25 7.55 .... Per 1 Ib. spool 2.30 2.45 2.80 3.20 3.75 4.40 4.85 5.25 6.55 8.4511.8514.45 ... 14428. WIRE, Copper, Magnet Wire, Enameled. The enamel insulation is an elastic yet resistant and firmly adhering film. This insulation is exceedingly inert toward the ordinary agencies met in practice, which cause silk or cotton insulation to rapidly deteriorate and lose their value as in- sulating mediums. Impervious to moisture. Requires less winding space. Positive dielectric strength. More feet to the pound. B. & S. No 26 28 30 36 40 Feet per oz 80 128 200 800 2000 Per 4 oz. spool .75 .75 .80 1.05 1.75 Per Ib. spool 1.85 1.95 2.00 2.90 5.45 14430. WIRE, Copper, Rubber Covered. B. & 8. No 12 14 16 Per foot 06 .05 .05 14432. WIRE, Copper, Soft, bare, on 4-ounce spools. Washburn & Moen No.. 16 18 20 22 24 26 27 28 30 32 34 36 Approx. diam., inches.. .063.047.035 028 .023 .018 .017 .016 .014 .013 .010 .009 Feet per spool 20 32 66 102 160 260 325 410 510 810 2050 3175 Per SDOol 40 40 .40 .45 .55 .60 .66 .66 .70 .80 1.10 1.80 For WIRE TABLES, see pages 527-8. 522 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 14434. WIRE, Copper, Stage Cable. Consists of two flexible conductors, insulated according to Under- writers ' specifications, the whole being covered with a black cotton braid, thus forming a sub- stantial single cable. Suitable for use with Arc Projecting Lanterns, Motors, etc. B. &S. No 10 12 14 Capacity, amperes Per foot $0.25 .20 .15 14438. WIRE, FUSE. Amperes % 1 2 3 5 6 10 12 15 40 Size of spools 4 oz. 8 oz. 8 oz. 8 oz. 1 Ib. 1 Ib. 1 Ib. 1 Ib. 1 Ib. 1 Ib. Feet per spool 400 500 340 220 168 145 82 66 53 17 Per spool 1.35 1.10 1.00 1.00 1.95 1.70 1.55 1.55 1.50 1.50 WIEE, German Silver, 18% alloy. B. & S. No 16 18 20 22 24 26 27 28 30 32 34 36 Approx. diam., in... .051 .040 .032 .025 .020 .016 .014 .013 .010 .008 .006 .005 14440. BARE WIRE. Per 4 oz. spool 85 .95 1.00 1.05 1.05 1.05 1.15 1.25 1.30 1.55 Per 8 oz. spool 1.40 1.45 1.55 1.70 1.70 1.80 1.80 1.95 2.15 2.35 2.75 Per 1 Ib. spool 2.35 2.35 2.50 2.70 2.85 2.95 3.00 3.10 3.25 3.65 4.05 4.85 14441. D. C. C. WIRE. Per 4 oz. spool 1.05 1.15 1.25 1.35 1.40 1.45 1.70 1.95 2.25 2.95 Per 8 oz. spool 1.60 1.80 2.00 2,20 2.40 2.55 2.65 3.05 3.60 4.25 5.60 Per 1 Ib. spool 2.70 2.85 3.15 3.55 3.90 4.25 4.55 4.75 5.45 6.50 7.8010.50 14442. D. S. C. WIRE. Per 4 oz. spool 1.80 2.00 2.20 2.30 2.80 3.50 4.60 5.60 Per 8 oz. spool 2.75 3.30 3.70 4.05 4.35 5.30 6.70 8.9510.95 Per 1 Ib. spool 4.30 5.15 6.00 6.90 7.55 8.15 9.9012.7017.2021.20 WIRE, Iron, see No. 14488 Steel Wire. 14450. WIRE, Iron, Chemically Pure, for standardizing, containing 99.85 per cent. Fe. In glass con- tainers. Size, ounces 4 Each .30 .60 1.00 14454. WIRE, Lead, diameter % inch Per foot .05 14464. WIRE, Nickel, pure, bare. B. & S. No 16 24 Per oz 25 .30 .35 14466. WIRE, Nickel-Copper Alloy, Ideal, bare, soft annealed, used in the manufacture of electrical instruments where extreme low temperature coefficient, accuracy and permanency are desired. Resistance is 29 times that of copper and temperature coefficient for 1° C. = +0.000005. B. & S. No 18 20 22 Per Ib 4.05 4.35 4.65 14468. WIRE, Nickel-Copper Alloy, Ideal, same alloy as No. 14466. Nos. 18 and 20 are double cotton covered. The remaining numbers are double silk covered. B. & S. No 18 20 22 24 26 28 30 32 36 38 Per oz 80 .85 .90 .95 1.15 1.40 1.50 1.90 2.80 5.50 Per Ib 6.00 6.75 7.05 7.50 9.00 10.05 12.00 14472. WIRE, Nickel-Steel-Chromium Alloy, Phenix, bare, used extensively in the manufacture of lan- tern rheostats, etc., where a high specific resistance combined with ability to withstand oxida- tion and corrosion is desired. Resistance is 50 times that of copper; temperature coefficient for 1° C. = +0.00054. B. & S. No 12 16 20 Per Ib 3.45 3.60 3.75 14476. WIRE, Piano, on spools. Music gage No 00 012345678 Approx. diameter, inches.. .0087 .009 .010 .011 .012 .013 .014 .015 .018 .019 Approx. feet on spool 15 15 14 12 12 12 10 10 8 8 Per spool 14478. WIRE, Piano, steel, in *4 pound rolls. Music gage No 1 2 4 5 6 7 8 9 Approx. diameter, inches 010 .011 .013 .014 .015 .018 .019 .022 Per roll 4.35 2.70 1.80 1.50 1.35 1.15 1.05 .90 Music gage No 10 12 14 18 23 26 Approx. diameter, inches .025 .028 .032 .040 .049 .061 Per roll 70 .65 .60 .55 .50 .50 14480. WIRE, Picture, steel, in packages of 25 yards. No 0 1 2 Per package — 15 .25 .30 14484. WIRE, Platinoid, bare; temperature coefficient .000286. B. & S. No 20 24 28 30 Per oz 60 .65 .75 .80 WIRE, Platinum, see general heading Platinum Ware. 14488. WIRE, Steel, annealed, soft, on 4-ounce spools. Washburn & Moen No 16 18 20 22 24 26 27 28 30 32 34 36 Approx. diam., in.. .063 .047 .035 .028 .023 .018 .017 .016 .014 .013 .010 .009 Per spool 13 .14 .15 16 .17 .18 .19 .20 .21 .22 .24 .30 For WIRE TABLES see paees 527-8. CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 523 No. 14522. No. 14514. No. 14546. No. 14548. 14492. 14494. 14496. 14504. 14510. 14512. 14516. 14520. 14522. 14526. 14528. 14534. 14544. 14546. 14548. WIRE, Tinsel, not insulated Per yard $0.15 WIRE, Tinsel, Conducting Cord. Oiie conductor. Tinsel wire covered with green braid. Very- flexible Per yard .10 WIRE, Tinsel, Conducting Cord. Two conductors, each covered with braid of distinctive colors: the -whole covered with another braid. Very flexible Per yard .30 WIRE, Zinc, diameter % inch Per foot .15 For WIRE TABLES see pages 527-8. WIRE GAGES, see Gages. WIRE GAUZE. Brass. Mesh 10 60 Per square foot .70 .75 .80 .90 WIRE GAUZE, Brass, 20 mesh, in squares f Jr use under dishes, beakers, etc. No A B Size, inches 4x4 5x5 Each 10 .U Per dozen LOO 1.40 WIKE GAUZE. Copper, for combustions. Mesh Per square foot 70 .80 WIRE GAUZE, Iron, 20 mesh, in squares for use tinder dishes, beakers, etc. No A B Size, inches 4x4 '5x5 Each 04 .05 Per dozen 40 .50 WIRE GAUZE, Tinned Iron, with flat asbestos center 3% inches in diameter, in squares for use under dishes, beakers, etc. No A B C Size, inches 4x4 5x5 6x6 Each -10 .12 .15 Per dozen 1-00 1.20 1.50 WIKE GAUZE, Nichrome, 16 mesh, will last almost indefinitely as the wire is practically rust- proof, and has an extremely high melting point, about 1500° C. (2800°F.). Size, inches " 4x4 5x5 6x6 12x12 Each 70 .90 1.30 4.00 WIRE GAUZE, Nickel, 30 mesh per square foot WORK BENCH. This bench is 50 inches long, exclusive of tail vise, or 56 inches over all. It is 32 inches high and 20 inches wide, with a 13 inch glued up maple top 1% inches thick and a 7 inch well for tools. It has holes for stops, and three spring wood stops are supplied. It is fitted with both front and tail vises, each having lV>-inch patent saw-cut threaded bench screws. Bench is fitted with both back board and tool rack, as shown in illustration. Weight packed for shipment, 120 pounds. F. O. B. Factory 12.95 WRENCHES, Monkey, good quality. Length, inches 8 Each 80 .90 WRENCH, Monkey, Pocket. 51A inches long WRENCH, Stillson's Pipe. 10 inches long, will take pipe from % inch to 1 inch 1.80 80 100 200 1.10 1.60 • •• • C F 6x6 12x12 .20 .70 2.00 7.00 60 80 100 .95 1.10 2.05 C F 6x6 12x12 .08 .30 .80 3.00 524 CENTEAL SCIENTIFIC CO., CHICAGO, U. S. A. RAW MATERIAL The following material has been selected with special reference to the laboratory shop. The prices are based on ordinary quantities and include cost of cutting. Special prices will be quoted on large orders. All prices are subject to market fluctuations. Castings in all metals supplied at market prices. Tor TABLES giving Comparative Weights of Metals, see page 528. ALUMINUM 14800. ALUMINUM ROD, full lengths 8 to 10 feet. (See note below.) Diam., in • % %6 % %e ¥2 Lbs. per ft 057 .089 .128 .174 .227 Per ft. . $0.12 .15 .21 .30 .40 % % % 1 .356 .516 .697 .911 .60 .85 1.05 1.35 14802. ALUMINUM SHEET, full sheets 12 inches wide, 5 to 6 feet long. (See note below.) Thickness, B. & S. No. 8 12 14 16 18 20 22 24 26 28 Lbs. per sq. ft ...... 1.8 1.13 .89 .71 .56 .45 .36 .28 .23 .18 Per sq. ft ........... 3.00 1.80 1.50 1.20 .90 .75 .60 .50 .45 .35 14804. ALUMINUM TUBING, seamless. Prices on application. ALUMINUM WIRE, see page 521. ASBESTOS ASBESTOS MATERIAL, see Nos. 308 to 326. 30 .14 .30 14830. BRASS ROD, Round, BRASS full lengths 12 feet. (See note below.) Diam., inches. . % %0 14 "He % 7x% Lbs. per ft 106 .212 .85 1.28 2.55 Per ft 10 .15 .35 .40 .75 14907. STEEL ROD, Cold Rolled, Round, full lengths 10 to 12 feet. (See note below.) Diameter, inches 14 %e %%%%%! Lbs. per ft 17 .27 .39 .67 1.1 1.5 2.1 2.7 Per ft 10 .10 .12 .15 .25 .30 .40 .55 14908. STEEL ROD, Cold Rolled, Square, full lengths 10 to 12 feet. (See note below.) Size, inches 14 % i/, % i Lbs. per ft 213 .478 .851 1.94 3.4 Per ft 12 .15 .25 .55 .85 14910. STEEL ROD, Coppered Bessemer, round, full lengths 4 feet. (See note below.) Diameter, inches % %6 14 tyio % %g % Lbs. per ft 05 .10 .17 .27 .39 .52 .67 Per ft 05 .05 .05 .10 .10 .15 .20 14312. STEEL ROD, Drill Rod, round, for tool making. Diam., inches. . % ytfi % ylrt % 7^6 i/2 6/lQ % i^e 04 i%6 % i^e j Per foot 15 .20 .25 .30 .40 .50 .65 .75 .90 1.00 1.25 1.50 1.75 1.85 2.00 14914. STEEL ROD, Magnet, Round. Diameter, inches *4 % % % % Per foot 15 .35 .60 .95 1.35 14915. STEEL ROD, Magnet, Square. Size, inches % % % % % Per foot 20 .45 .80 1.20 1.70 Hardening and magnetizing quoted upon application. TIN TIN SHEET, see Iron Sheet, tinned. 14930. TIN SHEET, pure block tin, B. & S. No. 22, 12 inches wide Per sq. ft. 3.10 14932. TIN TUBING. Pure block tin. Diameter, inside, inches %0 % %e % % % Ounces per foot 456 8 8 12 Per ft 75 .90 1.05 1.45 1.45 2.10 ZINC 14940. ZINC SHEET, thin, B. & S. No. 32 Per sq. ft .20 14942. ZINC SHEET. Thickness, inches }£2 We % %6 ^4 %e Lbs. per sq. ft 1.15 2.30 4.60 6.90 9.20 11.50 Per sq. ft 75 1.35 .2.80 4,00 5.35 6.65 ZINC WIRE, see page 523. NOTE: For convenience in shipping, certain items — rods, tubing, etc. — are cut in about 3-foot lengths, unless specially ordered in longer pieces. CENTRAL SCIENTIFIC CO.. CHICAGO, U. 8. A. 527 APPROXIMATE FEET PER POUND OF WIRE. Also Approximate Resistance of Copper and German Silver Wire. For sizes larger than No. 14, see table of weight of rods on page 528. B. &8. No. Aluminum Wire. Brass or G. S. Wire. Copper Wire. Iron or Steel Ohms per foot. Bare. D. C. C. j D. 8. C. Wire. Copper. | 18% G. S. 14 | 268 85 80 88 .00252 .0460 15 334 107 102 108 .00318 .n.-M. 16 - 417 132 128 l::!' .00401 .0732 17 526 171 162 i;- .00506 .0923 18 ~ 667 215 204 226 .00637 .1164 19 847 272 264 279 .00804 .1467 20 1 ."•;:: 343 324 298 312 353 .01014 j .1850 21 1,346 431 408 370 389 446 .01278 .2333 22 1,695 549 515 461 493 565 .01612 | .2941 23 2,123 684 650 584 631 714 .02032 .3710 24 2^580 869 819 745 779 909 .02563 .4678 25 3,389 1,086 1,033 903 966 1,124 .03231 | .5899 26 4,291 1,388 1,302 1,118 1,202 1,428 .04075 .7438 27 5,405 1,754 1,642 1,422 1,542 2,000 .05138 .9386 28 6,849 2,222 2,071 1,759 1,917 2,273 .06479 1.183 29 8,620 2,777 2,611 L',J"7 2,485 2,857 .08170 1.491 30 10,869 3,448 3,294 2,534 2,909 3,623 .1030 1.879 31 4. ..47 4,152 .'..'••* 3,683 4,566 .1299 2.371 32 5,555 5,236 3,737 4,654 5,649 .1638 2.990 33 7,142 6,602 4,697 5,689 7,194 .2066 3.771 34 9,090 8,328 6,168 7,111 | 9,090 .2605 4.756 35 11,111 10,501 6,737 8,534 11,493 .3284 5.997 36 14,084 13,258 7,877 10,039 | 14,493 .4142 7.560 37 38 QQ 1 16,691 20,854 1 OR 3 no 9,309 10,666 | 10,666 14,222 11 907 16 516 .5222 .6585 «. '.114 9.532 12.02 15~16 40 — ; | 33,176 14,222 21,333 1.047 19.11 WIRE GAGE TABLE. Showing sizes in decimal parts of an inch. Wire Gage Number. American or Brown & Sharpe. Washburn & Moen Mfg. Co. Music Wire. Wire Gage Number. American or Brown & Sharpe. Washburn & Moen Mfg. Co. Music Wire. 00 .365 .331 .0087 18 .0403 .047 .040 0 .325 .307 .0093 19 .0359 .041 .042 1 ,289 .283 .0098 ; 20 .0320 .035 .043 2 .258 .263 .0105 21 .0285 .032 .045 3 .229 .244 .0115 22 .0253 .028 .047 4 .204 .225 .0125 j 23 .0226 .025 .049 5 .182 .207 .0145 24 .0201 .023 .053 6 .162 .192 .0150 25 .0179 .020 .056 7 .144 .177 .0175 26 .0159 .018 .061 8 .128 .162 .0190 27 .0142 .017 .064 9 .114 .148 .0220 | 28 .0126 .016 .069 10 .102 .135 .024o 29 .0113 .01.1 .072 11 .091 .120 .0270 i 30 .0100 ."14 .076 12 .081 .105 .0285 ! 31 .0089 .0135 .081 13 .072 .092 .0305 ! 32 .0080 .013 .086 14 .064 .080 .0320 34 .01..;:: .010 .101 15 .057 .072 .0350 : 36 ;oss 11.027 11.671 9.790 9.337 3 .1^94 %2 :;.i<»r. 9.819 10.393 8.718 8.522 4 .2043 2.845 8.744 9.255 7.76.T" 7.589 5 .1819 yie 2.534 7.787 8.242 6.914 6.658 6 .1620 %2 2.256 6.934 7.339 6.157 6.018 7 .1443 2.009 6.175 6.536 5.482 5.354 8 .1285 % 1.789 5.499 5.821 4.88L' 4.773 9 .1144 1 ..V.M 4.898 5.184 4.348 4.251 10 .1019 1.418 4.361 4.615 3.871 3.756 11 .0907 %2 1.264 3.884 4.110 3.448 3.37 12 .0808 1.126 3.458 3.661 3.071 3.00 13 .0719 1.002 3.080 3.260 2.734 2.62 14 .0641 Me .892 2.743 2.903 2.435 2.32 15 .0571 .795 2.442 2.585 2.168 2.06 Hi .0508 .708 2.175 2.302 1.931 1.87 17 .0452 %4 .630 1.937 2.050 1.720 1.68 18 .0403 .561 1.725 1.826 1.531 1.50 19 .0359 .500 1.536 1.626 1.364 1.35 20 .0319 %2 .435 1.368 1.448 1.214 1.20 21 .0284 .396 1.218 1.289 1.081 1.05 22 .0253 .353 1.085 1.148 .963 .95 23 .0226 .314 .966 1.022 .858 .85 24 .0201 .280 .860 .910 .764 .75 25 .0179 .249 .766 .811 .716 .67 26 .0159 VM .222 .682 .722 .636 .60 27 .0142 .197 .607 .643 .568 .52 28 .0126 .176 .541 .573 .504 .45 29 .0112 .157 .482 .510 .452 .40 30 .0100 .140 .429 .454 .400 .37 Aluminum (99% pure) 1.61 Copper 1.00 German Silver (18% Nickel) 18.00 Gold (99.9% pure) 1.38 COMPARATIVE RESISTANCES OF METALS. (Copper as the Unit.) Nickel 7.78 riatinum (annealed) 5.65 Platinoid 20.00 Silver (annealed) 92 Iron . Lead 5.70 12.80 Tin . Zine 8.28 3.62 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 529 A Page Abbe Camera Lucida 343-344 Abbe Condensers 343 Abderhalden Reagents 82 Abel-Pensky Flash Point Testers 376 Abney's Reflecting Level (Clinometer) 482 Absorbent Cotton Disks 363 Absorption Apparatus, Chlo- rine 145 Absorption Apparatus, Heat. 445 Absorption Apparatus, Mois- ture 445 Absorption Bulks, all kinds. . 8, 9, 371. 413, 414 Absorption Paper for Fat in Milk 361 Absorption Paper for Botan- ical Mounting 95 Absorption Pipettes 293-294 Absorption Tubes 8, 9 Acetylene Burner 118 Acetylization Flask 246 Achromatic Objectives 348 Acid Basins 186 Acid Bottles 98 Acid Bottle for Milk Testing 856 Acid Bottle Trunnion 366 Acid Burettes 356 Acid Carboy Stands 129 Acid Dippers 356 Acid Dishes 185 Acid Feeder for Flotation Machine 251 Acid Funnel 257 Acid Gloves, Rubber 298 Acid Hydrometers 311-312 Acid Jars 329 Acid Measures 356 Acid Pipettes for Milk 356 Acid Pitchers 9 Acid Proof Cement 130 Acid Proof Finish 9 Acid Pumps 9 Acid Siphons 443 Acid Testers 356 Acidimeters 311-312 Acidity Testers for Soil 456 Acme Automatic Water Still 195 Acme Bunsen Burners 118 Acme Safety Burners 118 Actlnometer 312 Adam's Fat Extracted Paper 361 Adapters for Retorts 9 Adhesion Machine 18 Adhesive Tape 95, 486 Adhesivemeter. Brown's .... 18 Adiabatlc Calorimeter, Parr's 128 Adjustable Burners 118 Adjustable Clamps 149 Adiustable Bench Level 333 Adjustable Table 479.480 Aeroscopes 10 Agar Filter Paper 238 Agar Melting Water Baths.. 514 Agateware Boilers 329 Agateware Casseroles 130 Agateware Funnels 267 Agateware Kettles 329 Agateware Measures 336 Agateware Scoops 435 Agricultural Mills 177-181 Air Analysis Apparatus. . .10, 279 Air Baths 21. 23. 383-388 Air Baths. Flask 250 Air Compressors 88-92 Air Melting Point Oven 23 Air Meters 12. 289 Air Pumps 89-91, 414-416 Air Pumps, Filtering. .. .242. 243 Air Pumps. Mechanical 89-91 Air Pump Plates 416 Air Pump Receivers 79. 80 Air Pump Stop-Cocks 471 Air Sampler 10 Air Tester, Wolpert's 10 Air Testing Apparatus. 10, 82, 279 Air Thermometer Tubes 10 Alarm Thermometers 493 Albumlnometers 508 Albumoscope 508 Alcohol Blast Burners. . .120, 121 Alcohol Blowpipe 121 Alcohol Burners 120, 121 Alcohol Determination Appa- ratus 199. 204 INJDEX Page Alcohol Hydrometer ' 312 Alcohol Lamps 120 Alcohol Lamp Wlcklng 120 Alcohol Lamp Tripod 506 Alcohol Stoves 120. 121 Alcoholometers 312 Alembirs 427.428 Aliphatic Amlno Group Appa- ratus, Van Slyke 372 Alkali Hvdrometer 312 Alkali Reserve Determina- tion Apparatus for Blood.. Alkalimeters 129 Alkaline Tablets, Farrlng- ton's 3K7 Alkalinltv Flask. Volumetric 2KO Alllhn's Condenser 165 Alllhn's Gas Washing Bottle 294 Alsop's Drying Oven 514 Alternating Current Motors. 214-?15 Alternating Meters 210-211 Altimeter. Pocket 4*2 Altitude Gage 63-65. 27? Alumina for Pollshlner 338 Aluminum Balance Scoops. 61, s? Aluminum Beakers Aluminum Boxes 107. 187 Aluminum Desiccator Plates. 1*S Aluminum Dishes 187 Aluminum Foil 2KR Aluminum Funnel Supports.. 479 Aluminum Gas Tips 294 Aluminum Holders for Cen- trifuge Tube* 135. 13* Aluminum Leaf 2K6 Aluminum Milk Dishes. ..187, 35* Aluminum Moisture Dishes. . 1*7 Aluminum T?od 624 Aluminum Screw Cap Bottl»s 105. 357 Aluminum Sheet B24 Aluminum Rnoons 468 Aluminum Student Balance. . 40 Aluminum Tubing 524 Aluminum Weighing Dish with Counterpoise 61 Aluminum Weighing Scoop.. 61 Aluminum Wire S21 Alundum Cement 130 Alundum Combustion Boots.. 161 AluTidum Combustion Boat Lining 162 Al'mdum Combustion Boat Shields 162 Alundum Combustion Cap- sules 162 Alundum Conical Filters.... 237 Alundum Crucibles 170 Alundum Dish for Incinera- tions 162 Alundum Extraction Thim- bles 232 Alundum Filter Cones 237 Alundum Filter Dishes 238 Alundum Filtering Crucibles 170 Alundum Muffles 867 Alundum Melting Crucibles.. 170 AlunrtiiTTi "Pvromet^r Tubes.. ?fi1 Alundum Refractory Cement. TO Alundum. R R 162 Alundum Tubes 261 Alveolar Air T»stiner Outfit.. *2 Amber Gloss Bottles 98 Anibers-'s Swimming dins... 484 American Society for Testing Materials Sieves 442 Ames Moisture Tester 361 Ammeters and Mllliameters. . 209, 210, 212. 213 Ammonia, Nitrogen and Urea In TJrlne, Folln's Apparatus for 508 Ammonia Absorption Appa- ratus 11 Ammonia Determination Ap- paratus 11 Ammonia Distillation Appa- ratus, Kjeldahl's 369-371 Ammonia Gas 274 Ammonia Hydrometers SI 2 Ammonia Still 520 Ammonia Synthetic Appara- tus 332 Ammonia Test Cylinders.... 153 Page Ammonia Trap for Folln's Apparatus 508 Ampoules 11 Ampoules, PhenoI-Sulphone- Phthaleln 156 Anaerobic Culture Apparatus Analytical Balances 30-36 Analytical Filter Paper. . .239-241 Analytical Weights 55-67 Anatomical Jars 327 Anemometers Aneroid Barometers 63-64 Animal Bladders 81. 401 Animal Board Animal Cages 12. 1 Animal Holders Animal Jars Annealing Cups 13 Annunciator Wire 521 Anodes. Platinum 410 Anode Rotator 229 Antimony Rubber Tubing. . . . 43C Antitoxin Culture Flasks.... 182 Anvils 13 Anvils with Vises 511 Aplanatic Triplets 336 Apothecary Weights 59 Application Goniometer. Pen- field's 298. 299 Apparatus. Arsenic 16. 1 Apparatus, Asphalt Testing. 18-25 Apparatus. Blast 88-92 Apparatus, Blowplplng . . . .92-94 Apparatus for Carbon Deter- mination 8, 9. 153. 154. 159. 160-163 Apparatus. Carbonic Acid.... 129 Apparatus, Cement Test- ing 131-133 Apparatus for Collecting Bacteria 10 Apparatus. Combustion ..160-163 Apparatus for Counting Ba^- terla 168. 169 Apparatus. Creosote Testlng.18-25 Apparatus, Decomposition... 332. 333 Apparatus, Digestion ....369-371 Apparatus, Distilling 20-21. 195-200 Apparatus, Drying 204 Apparatus, Dust Determina- tion 10. 285 Apparatus, Electro-Chemical. . 229, 396-399. 403 Apparatus. Extraction 19. 22. 230-233 Apparatus, Filter 235-238. 2 Apparatus, Flour Testing. 252-25 Apparatus. Freezing 400 Apparatus. Fusel Oil Deter- mination 2 Apparatus, Gas Analysis. .276-294 Apparatus. Hardness Test- ing 303-30S Apparatus, Hoffman's ...332. 333 Apparatus. Kjeldahl 369-371 Apparatus, Lecture 332. 333 Apparatus, Melting Point. . . . 18, 23. 336 Apparatus. Methane Determi- nation 276. 294 Apparatus. Milk Testing. .356-364 Apparatus, Mine Air Testing 276. 277 Apparatus. Molecular Weight Determination 400, 401 Apparatus, Nitrogen Determi- nation 369-371 Apparatus, Oil Testing. . . 373-SSfl Apparatus, Pitch Testing. . .18-25 Apparatus, Radioactivity. . 423-426 Apparatus for Recalescence Point 263, 417-423 Apparatus. Shaking 438-440 Apparatus, Soil Analysis. 445-460 Apparatus, Stirring 470 Apparatus, Sulphur 475. 476 Apparatus, Tar Testing 18-25 Apparatus, Urinary 508-510 Apparatus. Vacuum Distilling 426 Apparatus, Vapor Density... 610-511 Apparatus, Water Analysis.. 520 Apparatus, Water Sampling. 520 Apparatus Supports 477-481 530 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Page Aprons 1. Aprons, Asbestos 1. Aquaria IB, 1 Aquarium Jars 1_ Arc Lamp for Microscopes... 341 Areometers 311-311 Argand Burners 114, 111 Armored Thermometers 492 Arnold Steam Sterilizers 469 Arrhenlus Conductivity Cells 396 Arrows, Surveyors' 48' Arsenic Apparatus 16 1' Arsenic Plates l( Arsenic Tubes r Artery Forceps 18! Artery Scissors 192 Asbestos Aprons 1< Asbestos Board r< Asbestos Cement i', Asbestos Center Gauzes 52! Asbestos Cloth 17 Asbestos Cord \'t Asbestos Drying Oven 388 Asbestos Gloves 291 Asbestos Mats 11 Asbestos Pads Asbestos Paper Asbestos Slate 11 Asbestos Twine 17 Asbestos Wire Gauze 523 Asbestos Wood 17 Ashing Dishes 129, 187, 188 Asphalt Crucible 20. 173 Asphalt and Tar Testing Ap- paratus 18-25 Asphalt Hydrometers 23 Asphalt Thermometers.18, 20, 492 Aspirating Syringe 485 Aspirators 242. 243. 445 Aspirator Bottles 98, 99. 446 Assay Balances 37 38 Assay Button Brush 108 Assay Button Weights 67 Assay Crucibles 170, 171, 173 Assay Cupels 182 Assay Flasks 246, 248 Assay Furnaces 264-269 Assay Furnaces for Gas 264. 265, 268. 269 Assay Furnaces for Gasoline . 264. 268. 269 Assay Mills 175-181 Assay Pocket Scales 38 Assay Roasting Dishes 188 Assay Supplies 182 Assay Ton Weights 67 Assayer's Mills 175. 181 Atom Models 366 Atomic Weight Charts 144 Atomizer Bulbs 88 428 Attaching Plug for Electrical Connections 227. 228 Attachments for Burettes.. . 113 Attachments for Burners 123 Attachment, Test Tube Fill- in* 488 Atwater Dessicator 184 Augers, Soil 452. 463 Auger, Soil Tube 460 Auger Bits 25 Autoclaves 26-29 Autoclaves for. Chemical Di- gestions (Digesters) 27, 28 Autoclaves. Steam Pressure Sterilizers 26-29 "Autogenor" Gas Generator.. 288 Automatic Air Compressor and Exhaust Pump 90 Automatic Alarm Thermome- . ters 493 Automatic Burettes 112 Automatic Burners. Barthel's 120 Automatic Depth Gage 304 Automatic Laboratory Micro- tome 352 Automatic Oil Measuring De- vice 302 Automatic Pipettes. . .87. 356. 404 Automatic Precision Micro- tome 358 Automatic Stills 195-198 Auxanometer 407 Avoirdupois Weights 58, 69 Ayrton-Mather Galvanometer . Shunt 206 Azotometers 371, 372 Hancock Bottles 357, 35? Babcock Bottle Rack 362 Page Babcock Milk Testers 359-361 Babo's Absorption Tube Bacilli Mills 179 Bacteria Collecting Appara- tus 10 Bacteria Counting Appara- tus 168, 169 Bacteria Filters 236, 237 Bacteria Grinding Apparatus 179 Bacteriolog leal Culture Flasks 182 Bacteriolog ical Culture Jars 11 Bacteriological Fermentation Tubes 234. 235 Bacteriological Filter Apa- ratus 235-238 Bacteriological Incubators... o-i o _i>9 r Bacteriological Syringes. . 484-48f Bacteriologists' Soil Sampler 454 Bagasse Cutter 179 Bags, Filter 237 Bags, Gas 282 Bags, Ice 317 Bags, Paper 391 Bags, Rubber 279, 282 Bailey Crucible Holder 174 Bailey - Walker Extraction Apparatus 230 Bakers' Scale 54. 252 Baking Cylinders 252 Baking Ovens, Electric. .381, 382 Baking Oven Thermometers. 255, 493 Baking Pans 253 Balance, Aluminum, Student. 40 Balances, Analytical 30-36 Balances, Assay 37, 38 Balances, Automatic 46 Balances. Cement 46 Balances, Cenco Analytical.. 36 Balance, Centrifuge Tube.... 143 Balances, Chainomatlc 30 Balances, Counter 47 Balances, Cream Testing.... 41, 47. 357 Balances, Decimal Milk 47 Balance, Demonstration .... 49 Balances, Dispensing 47. 54 Balances. Family Scales 48 Balance, Flour Testing. .. .54, 252 Balance, Gas Density 286 Balances, Grain Testing. .. .41, 64 Balances, Hand 48 Balance, Harvard Trip 54 Balance, Hydrostatic 51 Balances, Laboratory 40, 48, 49, 62, 53 Balance, Large Capacity and High Sensitiveness 33 Balance. Lecture Table 49 Balance, Magnallum 40, 49 Balances, Milk ...41, 47. 357 Balances, Moisture 42, 49 Balances, Platform 50 Balances, Prescription 42. 51 Balances, Pulp 39. 40 Balances, Seed Testing 41. 42 Balances, Soil 43. 61 Balances, Solution. . .42, 43, 51, 54 Balances, Specific Gravity. . . . .44, 51, 52 Balances, Spring 52, 53 Balance, Stoddard 63 Balances, Torsion 41-46 Balance, Trip 54 Balance, Triple Beam 65 Balance Brushes 109 Balance Covers 61 Balance Desiccator 61 Balance Levels 61 Balance Magnifier 61 Balance Pans 61 Balance Reading Glass 61 Balance Rests 61 Balance Riders 56 Balance Supports of Glass.. 61 Balance Wall Bracket 61 3alance Watch Glasses 61 Balance Weighing Scoops.. 61. 62 Balance Weighing Tube Sup- port 62 Balance Weights 55-60 Balls, Porcelain for Ball Mills 180 Balls, Steel, for Hardness Tester 304 Ball Mills 179.180 Ball Mill Jars 179, 180 Ball Tester 303. 304 Balling Hydrometers ....313, 315 Balloons 63 Balloons, Collodion 63 Balloons for Filtering-, Pukal 237 Balloons, Gas 63 Balloons, Glass 63, 245 Balloons, Rubber 63 Balloons, Specific Gravity.... 63 Balloon Flasks 245 Balsam Bottles 99 Bands. Rubber 428 Band Tubing, Rubber 431 Bars. Standard, for Hardness Tester 304 Bar Form Solder 460 Barker Carbon Dioxide Appa- ratus 129 Barkometers (Hydrometers). 312 Barnes Dissecting Micro- scopes 341 Barnes Dropping Bottle 99 Barographs 65 Barometers 63-65 Barometer Tubes 65 Barometer Tubing 297 Barrett Mfg. Co. Apparatus for Tar, Oils and Pitches. .18-25 Barthel's Alcohol Stoves 120 Barthel's Automatic Burners 120 Basket Form Slide Holder... 350 Baskets for Test Tubes 4R1 Bates Sugar Flask 250 Baths, Air 250, 383-388 Baths, Constant Temperature 383-385, 393. 394 Baths, Hot Air 2nO. 383-388 Baths, Paraffine Embedding. 392. 393 Baths. Sand 433. 434 Baths, Vaccine Culture. . .517-519 Baths, Wassermann 517-519 Baths, Water 513-520 Batteries, All Kinds 66-74 Batteries, Dry 66, 67 Batteries, Edison Primary... 67 Batteries, Galvanic '...66-74 Batteries, Plunge 69 Batteries, Primary 66-70 Battery, Standard Cell 70 Batteries. Storage 70-73 Battery Binding Posts 75 Battery Charger 313 Battery Connections 76 Battery Directions 74 Battery Fluid, Cenco Sulpho- Chromic 74 Battery Hydrometers 313 Battery Jars. . .66-70, 72, 326. 327 Battery Motors 214 Battery Porous Cups 66. 68 Battery Rheostats. . .214, 224, 225 Battery Screws 75 Battery Syringe 313 Battery Zincs 66-68. 61 Baumg Hydrometers 311-315 Beads, Glass 295 Beakers 77. 78, 475 Beakers, Aluminum 78 Beakers, Copper 78 475 Beaker, Digestion 475 Beakers, Fused Silica 78 Beakers, Glass 77, 78 Beakers, Griffin's 77 Beaker, Heavy Tumbler Shape 78 Beakers. Nickel Plated Cop- per 78, 475 Beakers, Phillips 246 Beakers, Porcelain 78 Beakers, Pyrex 77 Beakers, Sugar 78 Beakers, Transparent Quartz 78 Beaker Brushes 108 Beaker Clamps 146 Beaker Cover Glasses. .. .407, 512 Beaker Flasks 246 Beekmann Molecular Weight Determination Apparatus.. 400 Beckmann Thermometers . . . 493 Beehive for Pneumatic Troughs 506 Bees' Wax 521 Beer Hydrometer 313 Beer Still 199, 204 Beet Shredding Mills 181 Bell Glasses 79, 80 Bell Jars 79, 80 Bell Glass Dialyzer 186 Bellows 88 Bells, Electric 80 rKNTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 531 Page Belt Grinder 337 Belting, Leather -:.. 332 Bench Level, Adjustable 333 Bench Photometer. Station- ary 290. 291 Bender & Holbein's Potash Bulb 41S Bending Tubing, Glass 296 Eennert's Absorption Appa- ratus 204 Bennert's Drying Apparatus. 204 Bennings en's Elutriating Flask 247. 449 Benzine Hydrometer 3 Benzine Vapor Apparatus... 278 Berkefeld Filters ,... 235 Berkshire Sand 520 Bernard'sWire Cutting Pliers 412 Berzelius Gas Holders 288 Berzelius-Pepys Gas Holders 288 Bessemer Goggles 298 Biffl-Brooks Coagulometer. .. 83 Bimetallic Gas Regulator... 500 Bins 81 Binding Posts for Batteries. 75 Binding Screws, Battery.... 75 Bits, Auger 25 Bit Braces 81 Bitumen Crucible 20. 173 Bitumen Holder 23 Bituminous Testing Appara- tus 18-25 Black's Blowpipes 93 Black Lead Crucibles 172 Black Rubber Tubing 430. 431 Blackboard Drawing Instru- ments 202 Blackfan's Wet Cup 87 Blackmar Oil Thief 379 Bladders 81. 401 Bladder Glasses 80 Blades. Hack Saw 434 Blair's Drying Oven 388 Blair's Platinum Boat Holder 408 Blair's Platinum Combustion Boats 408 Blair's Platinum Dish 409 Blair's Separatory Funnel... 258 Blair's Stirring Apparatus. . . 470 Blair's Reductors 427 Blair's Rubber Policemen.... 429 Blair's Water Bath 514 Blake Pinning Forceps 256 Blast Apparatus. . .88-92, 122, 269 Blast Blowers 88-92. 269 Blast Burners 119-122. 269 Blast Burner, Fletcher's.... 120 Blast Burner, Massachusetts Institute Pattern 119 Blast Burners, Meker 120 Blast Burner, Wiesnegg"6. . . . 120 Blast Furnaces 262, 264, 265. 268. 269 Blast Lamps 119-122 Blast Lamps for Alcohol. 120. 121 Blast Lamps for Gasoline... 121 Blast Pumps, Air 89-92. 269 Blocks, Red Fiber 354 Block, Support, for Soil Tubes 459 Block Plane 406 Block Strop for Microtome Knives 355 Block Tin Pipe 626 Blood Apparatus 82-87 Blood Capsules, Wright's.... 82 Blood Coagulators 83 Blood Collector, Vacuum... 83. 84 Blood Counting Apparatus. 84. 85 Blood Drying Apparatus.... 83 Blood Gas Apparatus 82. 83 Blood Lancets 86 Blood Percentage Tubes for Haematokrit 134 Blood Pipette, Wright's 87 Blood Pipettes for Haemacy- tometers 85 Blood Testing Apparatus. .. 82-87 Bloom's Calomel Electrode. . 397 Blowers, All Kinds 88-92. 269 Blowers (Bellows) 88 Blowers, Blast 89-92, 269 Blowers, Crowell Positive Pressure 90. 91 Blower, Electric. Hot Air.... 88 Blowers, Foot 88 Blowers, Hand 88 Blowers, Power 89-92, 269 Blowers, Pressure 89-92. 269 Blower and Vacuum Pump Combined 89-92 Page Blowers. Water Pressure.... 92 Blowpipes, All Kinds 92, 93. 121. 189 Blowpipe, Alcohol 121 Blowpipe. Oxyhydrogen .... 93 Blowpipes for Zoological Work 189 Blowpipe Apparatus 93. 94 Blowpipe Capsules 93 Blowpipe Charcoal 93 Blowpipe Forceps 94. 256 Blowpipe Goods 93. 94 Blowpipe Hammers !»4. 303 Blowpipe Lamps 94 Blowpipe Matrasses 94 Blowpipe Mouthpieces 92 Blowpipe Platinum Mips.. 93. 408 olowpipe Reagents 94 iiiowpipe Set 94 Blowpipe Tips 93, 123. 408 Blowpipe Tubes for Bunsen Burner 123 Blue Glass Goggles 298 Blue Glass Plates 407. 408 Blue Green Hones 354 islue Print Paper 390 Board, Asbestos 17 Board, Botanical Mounting.. 95 Board, Drawing 201 Boards, Insect Spreading.... 326 Board of Health Tubes 141, 487. 488 Boats, Combustion 161, 162 Boats, Combustion, Clay.... 162 jboats. Combustion. Fused Sil- ica 162 Boats, Combustion, Platinum 408 Boats, Combustion, Porcelain 162 Boats, Combustion. Quartz... 162 Boats, tillering. Platinum... 408 Bobs. Plumb 412 UOCKIUS Measuring Bottle... 100 Boggs Coagulometer 83 toners, Agateware 329 toilers (Saucepans) 130 Boiling Flasks 244. 245 Boiling Point Apparatus. 400. 401 Boiling Point Tuoes 400. 401 Boland's Flour Tester 252 Bolting Cloth. Silk 255. 441 tolling Cloth Disks 520 Bomo Calorimeters for Coal and Oils 126-128 Eomb Calorimeter. Parr's, Adiabatic Oxygen 128 Bomb Calorimeter, Parr's, Oxygen 127 Bomb Calorimeter, Parr's. Standard 126 Bomb Furnace, Carius 270 Bomb Furnace, De Khotinsky 270 Bomb Tubes. Glass 297 Bone Ash Cupels 182 Bone-Cutting Forceps 189 Bone Mills 177. 178 Bone Saw 190 Books, Chemical Label 330 Books, Litmus 390, 391 Boots Specific Gravity Bottle 104 Borers, Charcoal 93 Borers, for Cork 167 Borers, Soil 452. 453 Boring Machine for Corks... 167 Boston Board of Health Ster- ilizer 469 Bostrom Level 483 Botanical Absorption Paper.95, 96 Botanical Adhesive Tape.... 95 Kotanical Collecting Case. ... 95 Botanical Drying Paper.... 95. 96 Botanical Genus Covers 95 Botanical Herbariums 96 Botanical Mounts, Riker's.... 95 Botanical Mounting Board... 95 Botanical Mounting Paper... 96 Botanical Plant Press 95. 96 Botanical Pressing Paper.... 96 Botanical Species Covers.... 96 Botanical Supplies 95, 96 Botanical Vasculum 95 Bottles, All Kinds 97-107 Bottles. Acid 98,366 Bottles, Aluminum Screw Cap 103, 106, 357 Bottles, Aspirator 98, 99. 445 ! Bottles, Balsam 99 Bottles, Bockius Measuring. . 100 Bottle, Butter Testing. . .357, 358 Bottles, Ceresine 106 Page Bottles. Combination Acid for Milk Testing ........... 356 Bottles, Cream Testing. . .357, 358 Bottle, Cyanide ............. 100 Bottles, Dropping .......... 99 Bottles. Ether .............. 105 Bottles, Gas, Cubic Foot ..... 292 Bottles, Gas Generating ..... 287 Bottles, Gas Washing ....... 294 Lotties, Graduated ...... 183, 31 Bottles, Gutta Percha ....... 103 Bottles, Hard Rubber ........ 103 Bottles. Homeopathic ....... Bottles, Immersion Oil ...... 1 Bottles, Insect ............. 100 Bottle, Measuring, Bockius.. 100 Bottles, Mechanical Analysis 446 Bottles, Milk Testing ---- 367. 358 Bottles. Mixing ......... 183. 327 Bottles, Oil Sample .......... 100 Bottles. Percolator ......... 3 Bottles, Pipette ............ 4 Bottles, Pressure ........... 100 Bottles, Reagent ........ 101-103 Bottles, Sample .......... ... 105 Bottles, Screw Cap ....... 103. 357 Bottles, Serum ............. 103 Bottles, Shaking ............ 455 Bottles, Shell Vials ......... 103 Bottles, Show .............. 104 .. . . 104. 105 Bottles, Specific Gravity for Cement ............... 104. 105 Bottles, Specific Gravity. Hubbard's ................ 104 Bottles, Specimen. . ..105, 327. 328 Bottles, Sputum ............ 141 Bottles, Tubulated ........ 98-107 Bottles, Vaccine ............ 103 Bottles, Volatile Liquid ...... 105 Bottles, Washing ---- 105, 106. 294 Bottles, Water Sample ....... 106 Bottles. Wax ............... 106 Bottles, Weighing ...... 106.107 Bottles. WoulflTs ............ 1 Bottle Brushes .......... 108, 109 Bottle Caps, Lead ........... 187 Bottle Caps, Reagent ........ 1 Bottle Forceps ............. 2 Bottle Rack. Babcock's ...... 3 Bottle Rest ................. 107 Bottle Shaking Apparatus... .............. 438-440, 454, 455 Bottle Trunnion, Acid ....... 356 Bougies for Filtering ---- 237, 238 Bourdon & Bourdet Hydroti- meter .................... SI! Bowen's Potash Bulb ........ 413 Bowls, Porcelain ........ 107. 263 Boxes, All Kinds ............ ........... 20, 107, 108, 241, 264 Boxes. Aluminum ....... 107. 187 Boxes, Cubic Inch ........... 252 Boxes, Tin ............... 20. 108 Boxes, Wood ............... 108 Boxes for Culture Dishes.... 181 Boxes for Filter Paper ....... 241 Boxes for Germinating. . .299, 300 Boxes for Micro Slides ....... 349 Boxes for Paraffine Embed- ding ...................... 354 Boxes, Pasteboard ..108, 241. 254 Boxes for Pipettes ........... 406 Boxes, Resistance ....... 220-222 Boxes. Slide ............. 108. 349 Box Form Electroscope ...... 42i Boxwood Measures .......... 435 Boxwood Rules ............. 435 Boyce Acme Safety Burner. . 118 Boyce Adjustable Burner.... 118 Brace, for Bits .............. 81 Brady's Sulphur Apparatus. . 8 Bramwell Penetrometer .... 133 Brass Blowpipes .......... 92. 93 Brass Condenser ............ 165 Brass Connecting Tubes ..... 506 Brass Crucible Tongs ........ 5 Brass Forceps ............ 62. 256 Brass Gauze ................ 523 Brass Rod .................. 524 Brass Sheet ................ 524 Brass Sieves ............. 440-442 Brass Stop-Cocks ....... 470. 471 Brass Strip ................ 524 Brass Wire ................. 521 Braun Acid Feeder .......... 251 Braun Blast Burners.119. 12S. 269 Braun Crucible Furnaces.264, 268 Braun Crushers ..... 175, 176, 181 532 CENTRAL, SCIENTIFIC CO., CHICAGO, U. 8. A. Page Braun Electrolytic Outfits... 229 Braun Flotation Machine. . . . 251 Braun Muffle Furnaces. .268. 269 Braun Oil Feeder 251 Braun Pulverizers 181 Braun Sample Grinders 176 Braun Samplers 433 Braun Vulcan Non-Blast Burners 119. 269 Brazing Blowpipe 93 Breast Drills 203 Breeding Cages, Insect 326 Bridges, Conductivity 222, 223, 403, 455 Bridge, Slide Wire 403 Bridges, Wheatstone 222, 223, 403. 455 Bridge Form Clamp Support 151 Briggs' Filtering Apparatus. 236, 237 Briggs-McLane Centrifuge... 447 Brinell Ball Testers 303, 304 Brinell Hardness Testers. 303. 304 Brinell Machines 303, 304 Brinell Magnifiers 304 Brinell Meter 304 Brinell Microscope 304 Briquette Mold, Asphalt..... 23 Briquette Molds for Cement. . 131 Briquette Mold Brushes 131 Briquette Rammer for Ce- ment 133 Bristles, Shoemakers' 189 Bristol Board 129 Brix Sugar Hydrometers.... 316 Brodie-Russell-Boggs Coagu- lometer 83 Bromwell Fusel Oil Appara- tus 271 Brown-Duvel Moisture Appa- ratus 301. 302 Brown Evaporator 22 Brown Oil Still 378 Brown's Pyrometers 417-419 Brown-Sharpe Calipers. . .125. 391 Brushes, All Kinds 108, 109, 131, 453, 459 Brushes for Briquette Molds. 131 Brushes, Sampling Tube. 109, 453 B. S. Tubes for Oil 140. 374 Buerker's Counting Chamber 84 Buck's Iron Mortar 367 Bucket for Waste 390 Bucking Boards 175 Bucking Board Brushes 103 Buechner's Funnels 268 Buffing Wheels. Muslin 412 Bulbs, Absorption 8, 9, 160, 161, 371, 413, 414 Bulbs for Constant Blast.... 88 Bulbs for Connecting, Kjel- dahl's 371 Bulbs, Drying. . .124, 413, 414, 424 Bulbs for Gas Apparatus.... 110 Bulbs, Glass 8. 9, 63, 110, 160, 161, 371, 413, 414 Bulbs, Leveling for Gas Bu- rettes 110 Bulbs, Nitrogen 371 Bulbs, Pipette 428 Bulbs, Potash 413, 414 Bulbs, Rubber 279. 428 Bulbs, Vapor Density 63, 510 Bulbs for Weighing Gases... 63 Bulb Connecting Tube for Marshall's Urea In Blood Apparatus 87 Bulb Expander 431 Bulb Tubes 199, 200, 427 Bulb Tube, KJeldahl's 371 Bulls-Eye Condenser 345 Bunsen Alkalimeter 129 Bunsen Barometer 65 Bunsen Battery 66 Bunsen Blast Lamp 119 Bunsen Burners.. 113-116, 118, 119 Bunsen Burners for Gasoline Gas 118 Bunsen Carbon Dioxide Ap- paratus 129 Bunsen Clamps 146. 148 Bunsen Condenser Clamps... 146 Bunsen Eudiometers 230 Bunsen-Fresenlus Chlorine Absorption Apparatus 145 Bunsen Funnels 257 Bunsen Oas Absorption Ap- paratus 145 Bunsen Measuring Tubes.... 289 Bunsen Photometers 290. 291 Page Bunsen Screw Clamp 148 Bunte Gas Burettes 282 Bureau of Mines Flash Point Testers 376 Bureau of Mines Gas Analy- sis Apparatus 276. 277 Bureau of Mines Gasoline Distillation Apparatus .... 374 Bureau of Soils Sieves 441 Bureau of Standards Sieves.. 441 isurtttes, All Kinds 111-113, 282, 283, 356, 363 Bui cues, Acid 356 Burettes. Automatic. 112, 356, 3tiJ Burettes, Caliorating 112 Burettes, certified 112, 113 Burettes, Dispensing 112 curettes. Gas Analysis. . .282, 283 .burettes. Precision 112, 113 Burette, Weighing 112 Burette Accessories 113 tiurettu Attachments 113 Burette Brush 108 Burette Caps 113 Burette Clamps 146 iiurette Funnel 113 Burette Pinchcocks i47 Burette Keader 113 tiurette Stop-Cocks 472 curette Supports 478 Burette Tips 113 Burrell's Gas Apparatus 278 Burker-Neubauer Haemacy- tometer 84 Burners, All Kinds 113-122, 264, 269 Burner, Acetylene 113 Burner, Acme Safety 118 Burners, Adjustable 118. 119 Burners, Alcohol 120, 121 Burners, Argand 114, 116 Burners, Barthel 120 Burners, Blast. . .119-122, 264, 269 Burners, Boyce 118 Burners, Braun Vulcan Non- Blast 119. 269 Burners, Bunsen. .113-116, 118, 119 Burner, Carpenter's Metro- politan Argand 292 Burner, Cary's Gasoline Blast 122. 269 Burners, Central Draft 114 Burner, Chaddock's 114 Burners, Coal Gas 113-120 Burner, Combustion Tube.... 116 Burner, Concentric (Radial) . 116 Burner, Dangler 122 Burner, Detroit 118 Burner, Evaporating 116 Burners, Fletcher's 116, 120 Burner, Fletcher's Blast 120 Burner, Gas Flame Testing. . 376 Burners for Furnaces. .. .264, 269 Burners, Gas Stoves 117 Burners for Gaseous Fuel. 113-120 Burners for Gasoline 121, 122, 264, 269 Burners, Gauze Top 116, 117 Burners, Glass Blowers' 117 Burner, Greenman 117 Burners, High Temperature. 119 Burners, Hot Plates for Gas. 117, 310 Burners, Hydro-Carbon 122, 264, 269 Burners, Illuminating 117 Burners, Kerosene 122, 264 Burners, Koch Safety 114, 115 Burners for Liquid Fuels.... 120-122, 264, 269 Burner, Low Temperature.. 116 Burners, Meker 115, 120 Burners, Micro 114 Burners, Multiple Tube ...115, 116, 119 Burners, Oil 122, 264 Burner, Pilot Light 113 Burner, Porcelain 114 Burner, Ring Form 118 Burner, Ring, for Tar Testing 20 Burner, Scimatco 119 Burner, Soldering Iron 118 Burner, Solid Flame 116 Burner, Spectrum 366 Burner, Teclu 118 Burner, Tlrrill's 118 Burner, Wiesnegg Blast 120 Burner Attachments 123 Burner Blowpipe Tubes 123 Burner Chimneys 114, 115, 123 Page Burner Crown Top 123 Burner Fork 123 Burner Gauze Top 123 Burner Guard 123 Burner Star 123 Burner Supports 123 Burner Tips 123 Burner Tripod 123 Burner Tubing 117, 430. 431 Burner Wicks 120 Burner Wing Tops 123 Burning Spoons 184 Burrell's Gas Apparatus 278 Butter Analysis Apparatus.. 356, 357, 361, 363. 364 Butter Fat Oil Tubes. .. .364, 488 Buttermilk Test Bottles 357 Button Balances 37. 38 Button Brush 93. 108 Button Forceps 94. 256 Button's Nippers or Pliers... 412 Button Weights 57 Cabinets, Desiccating 185 Cabinet, First Aid 243 Cabinets for Micro Slides 349 Cabinets, Proofing 254 Cabinets, Tool 503, 504 Cadmium Normal Elements. 397 Cages for Animals 12, 13 Cages for Insect Breeding... 326 Calcium Chloride Cylinders.. 124, 160 Calcium Chloride Drying Tubes 124, 160. 161 Calcium Chloride Holder for Balances 61 Calcium Chloride Jars and Tubes 124, 160. 161 Calcium Chloride Salometer (Hydrometer) 313 Calcium Chloride Tubes 124, 160. 161 Calculating Chart (Nomon) . 373 Calculator (Chemists' Slide Rule) 444 Calculi's Specimen Jars 328 Caldwell's Crucible 172, 174 Calibrallng Apparatus... .112, 404 Calibrating Buretles 112 Calibraling Pipettes, Ost- wald's 404 Calipers, All Kinds 125 Calipers, Micrometer 125 Calipers, Vernier 125 Caliper Rule 432 Calomel Electrodes 397 Calorimeters and Accessories 126-128, 283-285 Calorimeter, Mahler 127 Calorimeter, Parr's Adiabatic Oxygen Bomb 128 Calorimeter, Parr's Oxygen Bomb 127 Calorimeter, Parr's Standard 126 Calorimeter Press 128 Calorimeter Thermometers... 126, 127, 284, 494 Calorized Steel Pyrometer Tubes 421 Camel's Hair Brushes 109 Camera for Color Comparator Tubes 154 Camera Lucida, Abbe 343-344 Camp's Absorption Tube.... 8 Camp's Color Comparison Tubes 153 Camp's Shaking Apparatus.. 438 Campbell-Hurley Colorimeter 154 Canada Balsam Botlles 99 Candles, Photometric 292 Candles, Standard 292 Candles, Turbidimeter 507 Candle Balance 292 Candle Power Determination Apparatus 290, 291 Cane Sugar Mills 179. 181 Cans, Aluminum 107. 187 Cans, Soil Sample 107, 454 Capillarity Tubes for Soil.457. 458 Capillarity Tube Supporl 458 Capillary Eleclrode Tubes... 398. 399 Capillary Electrometers. .398, 399 Capillary Glass Tubing 297 Capillary Pipette 404 Capillary Stop-Cocks 471, 472 Capillary Tubing 297 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 533 Page Caps for Burettes 113 Caps for Reagent Bottles 102 Caps, Rubber, for Test Tubes 428 Caps, Tin 357 Capsules, Alundum 162 Capsules, Blood, Wright's... 82 Capsules, Clay Capsules, Combustion ...1211. 1 Capsules, Lead-Tin Foil 187 Capsules, Milk Analysis. .129, 358 Capsules, Porcelain 129, 187 Capsules, Silica 162 Capsule Spoon * Carbon, Granulated »24 Carbons for Arc Lamp 346 Carbon Apparatus, Parr's.... 126 Carbon Baths 513, 514 Carbon Blocks for Blowpip- ing Carbon Clamps 93 Carbon Combustion Appara- tus 160, 161. 409 Carbon Combustion Bulbs... 8,9 Carbon Comparison Tubes.. 153 Carbon Cylinder for Blowpip- ing 93 Carbon Determination Appa- ratus 160, 161, 409 Carbon Dioxide Apparatus, Frederlcia 82 Carbon Dioxide Apparatus, Van Slyke's 83 Carbon Dioxide Determina- tion Apparatus 129 Carbon Dioxide Freezing At- tachment for Microtomes.. 354 Carbon Dioxide and Methane Determination Apparatus.. 276 Carbon Dissolving Tubes.487. 488 Carbon Filament Lamps 331 Carbon Filter Tubes 257 Carbon Residue Flasks 247 Carbon Resistance Furnace.. 271 Carbon Rheostats 224 Carbon Rod 524 Carbon Sheet 524 Carbon Tubes 153 Carbon Tube Support 154 Carbonic Acid Apparatus.... 129 Carbonic Acid Determinaton Apparatus 129 Carbonic Acid Flasks 247 Carbonic Acid Gas 274 Carbonic Acid Generating Apparatus 287 Carborundum Paper 390 Carboys, Glass 129 Carboy Inclinator 129 Carboy Pumps 9 Carboy Stands 129 Carboy Tilter 129 Cardboard 129 Carius Explosion Furnace... 270 Carius Tubes 297 Carnot Funnel 258 Carnotite 425 Carpenter's Metropolitan Ar- gand Burner 292 Carpenters' Work Bench 523 Cartilage Knife 190 Cartilage Shears 193 Cartridges, Extraction. . .232. 233 Cartridges for Oxygen Gener- ator 288 Gary's Furnaces 269 Gary's Gasoline Blast Burner 122, 269 Gary's Hydro-Carbon Furnace Burners 122, 269 Cases for Blood Counters.... 85 Cases for Dissecting Instru- ments 193 Cases, Filter 241 Cases for Haemacytometers. 85 Cases, Mailing for Samples.. 254 Cases, Mailing for Slides 350 Cases for Pyrometers 419-420 Casein Tubes 138, 141. 358 Caslte Cupels 182 Casseroles, All Kinds 129-130 Casseroles, Agateware 130 Casseroles, Porcelain ....129-130 Casseroles, Silica 130 Cassia Flask 246 Cast Iron Crucibles 427 Catalase Apparatus 358 Cathodes. Platinum 410 Cavity Plates 408 fedar Oil Bottles 100 Cedarwood Oil. Immersion... 345 Page Cells, Battery 66-73 Cells for Calomel Normal Electrodes 397 Cells, Conductivity 396 Cells for Gas Electrodes 398 Cells for Half Elements 399 Cells for lonization 403, 399 Cells for Micro Slides 349 Cells, Porous 66,68 Cells, Selenium 438 Cells, Slide Mounting 349 Cells, Standard 70 Cell, Weston Standard 70 Celluloid Rule 432 Celluloid Strips 457, 458 Cement, Alundum 130 Cement, Asbestos 17 Cement, DeKhotinsky Labo- ratory 130 Cement, Liquid Porcelain.... 130 Cement, Loxol liO Cement, yuixo 130 Cement, Detractory Alundum 130 Cement, Kuober 429 Cement Briquette Molds 131 Cement Indenting Needles... 132, 133 Cement Molds 131-133 Cement Mold Brush 131 Cement Mold Tamper 132. 133 Cement Pan 132 Cement Scales 46 Cement Sieves 441 Cement Testing Apparatus.. 131-133. 135 Cement Testing Balances... 46 Cement Testing Machines... 131, 133 Cement Testing Molds 131-133 Cement Testing Sand, Stand- ard 132 Cement Testing Scales 46 Cement Testing Sieves 441 Cement Testing Trowels.... 133 Cenco Ammeters and Volt- meters 209 Cenco Analytical Balances.. 36 Cenco Blowers 89 Cenco Blower and Vacuum Pump 89 Cenco Electric Heater for Volatile Fluids 233. 305 Cenco Electric Motors 216 Cenco-Nelson Pumps 415 Cenco Polar Stills 196, 197 Cenco Rheostats 224 Cenco Stencils 463 Centigrade Thermometers, All Kinds 490-499 Central Draft Bunsen Burn- ers 114 Centrifugal Machines ....141-143 Centrifuges and Accessories 19. 134- 143, 359. 360, 373, 374, 446, 447 Centrifuges for Asphalt Test- ing 19 Centrifuges, Electric 19, 135-140, 359, 360, 374, 446, 447 Centrifuges, Hand and Wa- ter Motor 134, 373 Centrifuges for Mineral Ag- gregate 19 Centrifuge, Moisture Equiva- lent 447 Centrifuges for Oil Testing.. 373, 374 Centrifuges, Soil 446. 447 Centrifuge Heads 134, 136, 138-142.439 Centrifuge Tubes 134, 135, 138, 140, 141, 374, 446 Centrifuge Tube Balance 143 Ceresine Wax Bottles 106 Certified Burettes 112. 113 Certified Cylindrical Gradu- ates 183 Certified Thermometers. . .491-495 Certified Volumetric Flasks. 250 Certified Volumetric Pipettes 406 Chaddock Beaker and Dish Clamps 146 Chaddock Burette Support... 478 Chaddock Burner 114 Chaddock Clamps 146, 147 Chain Vernier Balances 30 Chain Tapes 484 Chalk Line 165 Chamberland-Pasteur Pres- sure Filters 236.237 Page Chambers, Moist 181 Chamois Skins 144 Chancel's Gas Apparatus.... 281 Chapman's Filter Pumps 242 Charcoal, Blowpipe 93, 144 Charcoal Borers 93 Charcoal Capsules 93 Charcoal Holders 93 Charcoal Squares 93 Charcoal Sticks 93. 144 Chardin Filter Paper 238 Charging Cap 424 Charging Rod for Electro- scopes 424 Chargometer (HydromeWr).. 313 Chart, Cross Section 169 Charts, Element 144 Charts. Frost's Gasometer. . . 235 Charts, Lecture Room 144, 145, 169 Charts, Metric 145 Charts. Milk Record 358 Charts, Spectrum 145 Charts, Wall 144, 145. 169 Cheese Cloth 145 Chemical Centrifuges ....134-143 Chemical Labels 330. 331 Chemical Stencils 463 Chemical Ta"bles 144 Chemical Thermometers. .490-492 Chemists' Slide Rule 444 Chests of Tools 503, 504 Chidlow Expansion Jar 252 Chldlow Gas Collecting Jar.. 253 Chimneys, Argand 114, 145 Chimneys for Burners 114, 115, 123, 145 Chimney, Star Support for... 123 Chimneys, Student Lamp. 145. 458 Chipmunk Crushers 175, 176 Chisels 145 Chisel Blade Microtome Knife 355 Chloride of Calcium Cylin- ders 124, 160. 161 Chloride of Calcium Holder for Balances 61 Chlorine Absorption Appara- tus 145 Chlorine Gas, Liquefied *74 Chlorine Generators 287 Chlorine Tube 145 Chopper, Meat 178, 179, 181 Chrome Steel Crushers. 175 Chromel Triangles,. Hoskins'. 505 Chronometer 473, 474 Churns, Dasey 358 Circular Saws 412 Claissen Distillation Flask.. 246 Clamps, All Kinds. .. 146-152, 403 Clamps, Battery 76 Clamps, Culture Jar 327 Clamp, Meter Stick 160 Clamps, Watch Glass 148 Clamp Fasteners 148 Clamp Holders 148 Classen's Platinum Dish for Electrolytic Separation 409 Classen's Platinum Electrode 4 Claw Hammer 303 Clay Capsules Clay Combustion Boats 162 Clay Combustion Tubes 163 Clay Covers for Petrl Dishes. 181 Clay Crucibles 93, 170. 171 Clay Pipes 404 Clay Plates. Porous 408 Cleaners, Beaker 108 Cleaners, Burette 108 Cleaners, Test Tube 110 Cleveland Fire Tester 375 Clinical Microtome 351. 352 Clinical and Physiological Apparatus 82-87 Clinical Thermometer for Veterinary Use 494 Clinometer, Abney's 482 Clinostat 407 Clips. Spring 152 Clips, Watch Glass 148 Clock, Interval Timer 152 Clocks. Laboratory 152 Closets. Glass for Drying.... 185 Cloth. Emery 230 Cloth, Cheese 145 Cloth, Cotton 152 Cloth, Rubber 429 Cloth for Sampling 433, 454 Cloth, Silk Bolting 255,441 Cloth, Tracing 162 Cloth Counting Glass 334 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. P:-p-e (.loth Oil Tester 379 Cloth Tape 95, 486 Cloth Testing Machines 489 Coagulators for Blood Serum Coagulometers 83 Coal Ashing Dishes 162, 188 Coal Calorimeters 126-128 Coal Crushers 175-181 Coal Gas Burners 113-120 Coal Grinders 176 Coal Oil Pyrometers 422 Coal Samplers 432. 433 Coats, Laboratory 14 Cobalt Glass Plates 407 Coils, Cooling for Water Baths 517 Coils, Induction 208, 399 Coils, Resistance 223 Coll Heaters, Electric 306 Coll System for Galvanome- ters 206 Coke Grinders 176 Cold Chisels 145 Cold Test Thermometers.... 496 Collars, Hook 149 Collecting Apparatus for Bacteria 10 Collecting Case, Botanical... 95 Collecting Needles, •Wasser- mann 83 Collecting Trowel 506 Collecting Tubes for Blood. 83, 84 Collecting Tubes for Gases.. 286 Collections, Mineralogical. . . 364, 365 Collodion Balloons 63 Colony Counting Apparatus. . 168, 169 Color Comparators 153-159 Color Comparison Tubes 153 Color Comparison Tube Cam- era 154 Color Dissolving Tubes.. 487, 488 Color Reaction Plates 408 Color Testing Apparatus. .153-159 Color Tray for Soils 457 Color and Turbidity Determi- nation Apparatus 159, 507 Colored Glass Goggles 298 Colored Glass Plates 407. 408 Colorimeters 154-159 Colorimetric Determination Apparatus 153-159 Colorless Lacquer 330 Combination Pliers 411 Combination Saw 434 Combination Square 463 Combined Acid Bottle, for Milk Testing 356 Combustion Apparatus.. . .160-163 Combustion Boat Lining. . . . 162 Combustion Boats 161, 162 Combustion Boats, Platinum 408 Combustion Boat Shells 162 Combustion Capsules. 129, 162, 187 Combustion Crucibles, Plati- num 408. 409 Combustion Furnaces. 116, 260-262 Combustion Furnace, Fletch- er's 262 Combustion Furnaces, Gas Heated 262 Combustion Furnace, Glaser's 262 Combustion Furnaces. Hos- kins 260 Combustion Furnaces, Multi- ple Unit Electric 261 Combustion Spoons 184 Combustion Tester 278 Combustion Train, Johnson's 160 Combustion Train, Vanier's. . 161 Combustion Tubes. ..163, 297, 408 Combustion Tubes. Platinum. 408 Combustion Tube Burner. . . . 116 Combustion Tubing, Glass... 297 Comer's Automatic Pipette.87, 404 Compacting Machines. .. .447, 448 Comparators, Color 153-159 Comparison Tubes, Color. 153. 154 Comparison Tube Support... 154, 159 Compartment Incubators .... 321 Compartment Ovens 387, 388 Compasses, Drawing. 163, 201. 202 Compasses, Magnetic 164 Compasses, Pencil 163 j Compound Blast Burner 120 Compressed Air Burners, Me- ker 120 Compressed Cork Mats 168 Page Compressed Cork Rings 168 Compressed Gases £74. 275 Compression Pumps for Gases 89-91, 414 Compression Testing Machine for Cement 131 Compressors, Air 89-91, 414 Compressors, Clamp Screw.. 148 Compressor Screw for Rubber Tubing 148 Concave Slides 349 Concentric Rings 428 Concentric Ring Tripod 505 Condensed Milk Hydrometers 314 Condensers, All Kinds 165, 230-232, 369 Condenser, Bulls-Eye 345 Condenser for Extraction Ap- paratus 230-232 Condensers, Kjeldahl 369 Condenser, Substage 343 Condenser, Tar Testing 375 Condenser Clamps 146, 147 Condenser Supports 478 Condenser Trough, for Tar Testing 20 Condenser Tubes 166 Condenser Tube for Urea, Fo- lin 508 Conducting Cord 623 Conductivity Apparatus .... 448 Conductivity Bridges 403, 465 Conductivity Cells 396 Conductivity Cell Support... 397 Conductivity of Electrolytes Apparatus and Accessories. 396-403 Conductivity Lecture Appa- ratus 332, 333 Conductivity Vessel Clamp... 397 Cones, Filtering, Alundum... 237 Cones, Filtering, Platinum.. 408 Cones, Filtering, Porcelain. .. 238 Cones, Measuring 273 Cones, Steel 273 Cone of Wood 408 Configuration Atom Models.. 366 Congo Test Paper 390 Conical Beakers 246 Conical Glasses 487 Conical Graduates 299 Connecting Bulbs, Kjeldahl.. 371 Connecting Tubes 506 Connecting Tubes for Mar- shall Urea in Blood Appa- ratus 87 Connectors for Batteries.... 76 Connectors, Hose 308 Connectors for Stop-Cocks... 471 Constant Level Water Tank.. 285 Constant Pressure Regulator 274, 275, 294 Constant Temperature Baths. 401-403, 516-519 Constant Temperature Ovens 383-385 Constant Temperature Regu- lators 500, 501 Contact Goniometers, Pen- field's 298, 299 Contact Keys 228, 229 Containers or Bins 81 Converters, Rotary 226 Co-ordinate Paper 169 Coplin's Staining Jar 328 Coppers, Soldering 460 Copper Analysis. Braun Elec- trolytic Outfit for 229 Copper Assay Flasks. .. .246, 248 Copper Beakers 78 Copper Crucibles 171 Copper Condenser 165 Copper Determination Flask 248 Copper Distilling Flasks 248 Copper Drying Ovens 386-388 Copper Fermentation Tube Support 235.478 Copper Flasks 246, 248 Copper Flasks for Moisture Test 248 Copper Funnels 258 Copper Gas Holder 288 Copper Gauze 523 Copper Measures 336 Copper Oxide Flasks 246 Copper Paraffine Embedding Baths 392, 393 Copper Retorts 427 Copper Rings 428 Copper Rod 525 Page Copper Sheet 525 Copper Stills 195-199, 204 Copper Test Tube Supports. 480 Copper Tubing 526 Copper Water Baths 513-520 Copper Wire Gauze 523 Cord, All Kinds 17, 165 Cord, Asbestos 17 Core Baking Oven 390 Corks 166, 167 Corks, Rubber 301, 429 Cork Borers 167 Cork Borer Sharpener 167 Cork Boring Machine 167 Cork Extractors 167. 168 Cork Files 235 Cork Gage 168 Cork Knife 168 Cork Mats 168 Cork Plates 168 Cork Press 168 Cork Rings 168 Cork Sheet 168 Corkscrews 168 Corn Test Sieves 302, 441 Cornet Cover Glass Forceps.. 256 Coronary Artery Scissors.... 192 Corper-DeKhotinsky Staining Apparatus 464 Corrosive Sublimate Tablets. 363 Cots, Finger 243 Cottle Extraction Apparatus. 231. 232 Cotton, Absorbent 8 Cotton for Plugging Test Tubes 8 Cotton Cloth 162 Cotton Thread 501 Cotton Twine 507 Coulometer, Washburn's Io- dine 397 Counter, Hand Tally 168 Counters, Thread 334 Counter Balance 47 Counter Brush 108 Counterpoised BalanceScoops 61, 62 Counterpoised Support for Weighing Bottles 62 Counterpoised Watch Glasses 61. 512 Counterpoised Weighing Scoops 61, 62 Countershafts for Motors. 216, 416 Counting Apparatus for Bac- teria 168, 169. 520 Counting Apparatus for Blood 84, 85 Counting Chambers 84. 85 Counting- Pipette for Bacteria in Milk 404 Counting Plates 168, 169 Couplings for Filter Pumps.. 242 Cover for Balances 61 Covers for Beakers 20, 407 Covers, Botanical Genus 95 Covers, Botanical Species.... 96 Covers. Earthenware for Pe- tri Dishes 181 Covers, Porous Clay 181 Covers and Receivers for Sieves 441 Cover Glasses for Haemacy- tometers 84, 85 Cover Glasses, Micro 350 Cover Glass Forceps 256 Crash Towelling 504 Crayons. Wax 395 Cream Bottle Brushes 109 Cream Pipettes 362 Cream Test Balances. .41, 47. 357 Cream Test Bottles 357. 358 Cream Testing Apparatus. 359-361 Cremator, Electric 169 Creosote Flasks, Hempel 246 Creosote Funnels 257. 259 Creosote Sulphonation Test Funnel 259 Creosote Testing Apparatus. 18-25 Crooke's Radiometer 426 Crosscut Saws 434 Cross Section Chart 169 Cross Section Paper 169 Crowell Blast Apparatus .. .90, 91 Crowell Positive Pressure Blower 90, 91 Crowell Rotary Air Pumps. 90, 91 Crowell Vacuum Pumps.... 90. 91 Crowfoot Batteries 68 Crown Rolling Mills ISO CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 535 Page Crown Top for Bunsen Burn- er 123 Crucibles, All Kinds 13, 20, 93. 170-174 Crucibles, Alundum 170 Crucibles, Assay. 13, 170, 171. 1 Crucibles, Black Lead 172 Crucibles, Caldwell 172. 174 Crucibles, Clay 13, 93. 170. 1 Crucibles. Copper 171 Crucibles, Denver 170, 171 Crucibles. Filtering, Alun- dum 170 Crucibles, Filtering, John- son's 171 Crucibles, Iron 171. 174 Crucibles, Melting, Alundum 170 Crucibles. Nickel 171 Crucibles, Normal School.... 174 Crucibles, Platinum 408. 4i Crucibles. Plumbago 172 Crucibles. Porcelain. .20. 172. 173 Crucibles, Porcelain, Gooch for Asphalt 20, 173 Crucibles, Quartz 1 Crucibles, Rose's 1 Crucibles, Sand 173 Crucibles, Silica 174 Crucibles, Sliver 174 Crucibles, Skidmore 174 Crucibles for Sulphur Deter- mination in Coal and Coke 1' Crucibles. Transparent Quartz 173 Crucible Furnaces, All Kinds 263-265. 268 Crucible Furnace, Braun's... 264 Crucible Furnace. Case Melt- ing 264 Crucible Furnaces, Fletcher's 264, 265 Crucible Furnaces, Hoskins.. 263 Crucible Furnaces, Multiple Unit Electric 263 Crucible Holders 174 Crucible Supports 1 Crucible Tongs 502. 503 Crucible Tubes, Rose's 173 rrurible Tubing. Rubber 431 Crude Fiber Flask 249 Crushers, All Kinds 175-181 Crushers. Ice 3 Crushers, Ore 1 Crusher Brushes 109 Crushing. Grinding and Pul- verizing Apparatus ....175-18 Gyroscopes 400 r-rvsta'lization Dishes 188 Cube Molds for Asphalt 23 Cube Molds for Cement 132 Cubic Foot Gas Bottles 2P2 Cubic Inch Box 252 Culture Apparatus, Anaero- bic 11 Culture Dishes 181 Culture Dish Holders 181 Culture Flasks 182 Culture Jars 11 Culture Slides -349 Culture Tubes 487, 488 Culture Tube. Keldel Vacuum for Blood 84 Culture Tube Baskets 481 Cups. Annealing IS Cup, Blickfan's Wet 81 Cups, Embryological 18! Cups, Porcelain 25! Cups or Cells, Porous for Batteries 66,6! Cups, Swimming 484 Cup. Water Retention 46( Cupels 182 Cupels, Bone Ash 182 Cupels. Caslte 18! Cupel Holders 94. 182 Cupel Machines 182 Cupel Molds 182 Cupel Rake 182 Cupel Shovel 182 Cupel Tongs 503 Cupel Tray 182 Current Rectifiers 217-219 Current Slide. Holman 349 Cut-off Clamps 147 Cut-out Plug 227 Cutter. Bagasse 179 Cutters, Glass, All Kinds. 295, 296 Cutters. Glass Disk 295 Cutters, Glass Tubing 295. 296 Butter. Potato 414 Cyanide Bottles for Insects.. 100 Page vlinders. All Kinds 124. 153, 183, 237, 238, 252. 274, 275 ylinders. Ammonia Test.... 153 'ylinders. Baking 252 Cylinders, Calcium Chloride. 124 Cylinders, Filter 237, 238 Cylinders, Gas, for CO* OTV- gen. etc 274. 275 ylinders, Glass 183 Cylinders. Graduated Preci- sion 183 'ylinders, Hehner*s 153 i Cvlinders, Hvdrometer 183 i vlinders. Mixing 183 vlinders, Mixing. Precision. 183 vlinders for Moisture Test- ers 183 Cvlinders, Porous Filtering.. 237. 238 Cylinders for Nessler Ammo- nia Test 153 vllnders. Steel for Gases. 274. 275 Cylinder Brushes 108. 109 ^vlinder Tongs 255. 503 r-vlindrlcal Graduates 183 Cylindrical Shelf for Pneu- matic Troughs 506 n D ' Arsonval Galvanometers and Accessories 205-207 Dairy Cattle Score Cards.... 363 Dairy Thermometers 364 Daland Haematokrlt 134 Dam, Rubber 421 Dangler's Gasoline Burner. . 122 Dangler Lamps 122 Danlell's Battery 66 Dark Field Condensers 344 Dasey Churns 358 Davy Safety Lamp 332 Day Spring Pinch Cock 147 Daylight Lamps ....155. 345-347 Decade Dial Resistance Boxes 221 Decalescent Outfit 410 Decimal Balances 47 Decimal Stop Watches. . .473-47J Decimeter Rules 435 Decomposition of Water Ap- paratus 332 Deflagration Globes 184 Deflagrallon Spoons 184 Dehydrating Apparatus for Tar and Creosote Oils t* DeKhotlnsky Cement 130 DeKhotlnsky Cremator, Elec- tric 169 DeKhotinsky Drying Ovens. . 383-385 DeKhotlnsky Hot Air Steril- izers 466 DeKhotlnsky Immersion Heaters 307 DeKhotlnsky Incubators. Tri- ple Wall 318-319 DeKhotlnsky Laboratory Ce- ment 130 DeKhotlnsky Staining Appa- ratus 464 DeKhotlnsky Thermo-Ree-u- lators 383. 500 DeKhotlnsky The r m o s t a t Baths 401-403 DeKhotlnsky Tube or Bomb Furnace 270 DeKhotlnsky Water Baths.. 515. 516. S18 Delivery Bulb Tube 371 Demonstration Ammeter .... 213 Demonstration Balance Demonstration Galvanometer 213 Demonstration Lecture Ar>- paratus 332, 3 Demonstration Microscope... 3 Demonstration Thermometer. 49fi Demonstration Voltmeter ... 213 Dennlson Labels 329. 33C Dental Dam 429 Denver Fire Clay Crucibles.. 17». 171 Denver Fire Clav Muffles.... 367 Denver Fire Clay Roasting Dishes Denver Fire Clav Scorlflers.. 43f Depth Cutling Saw 434 Depth Gage. Automatic 3-5 Haematokrit ........... • • . • • If 4 Haematology, Apparatus for.82-87 Haemoglobin Standard. Kutt- ner ....................... Haemoglobinometers ........ 85 Haessler-Newcomer Haemo- globlnometer ............. Hair Hvgrometers ......... . 315 Half Elements for Physical Chemistry ................ 8 Half Meter Sticks ........... 435 Half Round Files ............ 2 Hall's Purlnometer .......... 5 Hammers ................ 94. 3 Hammers. Blowpipe ...... 94. 3< Hance Mills ................ 177 Hand Balance ............... Hand Blowers .............. Hand Drills ........ 203, 204. 295 373 346 * 335 3 4 1 168 512 235 355 291 488 427 103 107 258 461 506 526 94 305 304 481 358 142. Hand Feed Arc Lamp ........ Hand Level ................ Hand Magnifiers ........ 334. Hand Microtome ............ Hand Samplers for Coal. etc. Hand Screw Clamps ......... Hand Tally ................. Hand Vises ................ Handles for Files ............ Handle for Microtome Knives Harcourt Pentane Lamp ..... Hard Glass Test Tubes. . . .94. Hard Glass Tubes for Blow- piping .................. 94. Hard Rubber Bottles ........ Hard Rubber Bottle Rest ---- Hard Rubber Funnels ....... Hard Rubber Spatulas ....... Hard Rubber Tubes ......... Hard Rubber Tubing ........ Hardness Scale ............. Hardness Testers ........ 303 Hardness Test Measuring Mi- croscope .................. Hardwood Supports ...... 477 Hart's Casein Tube.. 188, 141. 540 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. Page Harvard Trip Balance 64 Hasselbalch Gas Electrode.. 398 Hatchet 306 Heads for Centrifuges 134, 136. 138-142 Heat Absorption Apparatus.. 446 Heat Gages 417-423 Heat Treating Furnaces. 263. 271 Heaters, Electric, All Kinds 233, 234. 305-310. 360 Heaters, Electric (Hot Plates) 308-310 Heaters, Electric Coll 306. 307 Heaters. Electric for Milk Testers 360 Heaters, Extraction Appara- tus 233. 234 Heaters for Flasks 250 Heater for Flasks, with Hot Plate 306 Heaters for Soldering Irons. . 118 Heaters, Water, Instantane- ous 307. 308 Heating Devices for Incuba- tors 321. 322 Heating TTnits, DeKhotinsky Standard 307 Heating Wire 260. 261, 263, 266, 267, 522 Heavy Beakers 78 Heeren's Ploscope 362 Hehner's Color Comparator.. 153. 520 Hehner's Color Tubes. .. .153. 520 Hehner's Cylinders 153, 520 Helm's Animal Cage 12 Hempel Distillation Flask... 246 Hempel Distilling Tube for Tar 200 Hempel Gas Burettes. .. .282, 283 Hempel Gas Palladium Tube. 290 Hempel Gas Pipettes 293. 294 Hempel-Tutweiler Gas Bu- rette 283 Hempel-Wlnkler Gas Burette 282 Hennlnger-Le Bell's Distill- ing Tubes 200 Herbariums 96 Herman Electrolytic Outfit.. 229 Hess-Ives Tint Photometer. . 156 Hlggln's Water Proof Ink... 201 High Range Thermometers.. 491 High Resistance Pyrometers 417-419 High Speed Turbine Stirrers 470. 517. 518 High Temperature Burners.. 119 Hlerh Temperature Drying Oven 387 High Temperature Furnace.. 271 Hierh Vacuum Pumps 415 Hildebrand's Calomel Elec- trode 397 Hildebrand's Gas Electrode.. 398 Hind's Gas Generators 287 Hinman-Jenklns Gas Appara- tus 282 Hlrsch Funnels 258 Hlstologlcal Apparatus for Embedding 354. 392-395 Hitrhens Svrlnge 486 Hoffmann Clamps 146. 148 Hoffmann Lecture Apparatus. 332 Hoffmann Water Bath 517 Hogarth Specific Gravity Bot- tle 104 Hoist for Soil Tubes 454 Holders, Animal 12, IS Holders for Charcoal 93 Holders for Conductivity Cells 397 Holders for Crucibles 174 Holders for Culture Dishes.. 181 Holders for Cupels 94 Holders for Dishes 181 Holders for Extension Clamps 148 Holders for Gas. .282. 285, 286, 288 Holders for Microtome Knives 365 Holders for Needles 190. 326 Holders for Petrl Dishes.... 181 Holders for Slides 256,350 Holders for Test Tubes 146, 147, 480. 481 Holders for Tools 503, 504 Holders for Triangles 605 Hollard's Platinum Electrodr 410 Holman's Current Slide 349 Holman's Siphon Slide 349 Homeopathic Vials 99 Hones 354 Honing Backs 855 Page Hooks and Chains 190 Hooks, Collar 149 Hooks, Screw 438 Hopkins Connecting Bulb Tube 371 Hopkins Distilling Tube 371 Hopkins Kjeldahl Connecting Bulbs 371 Hopkins Limestone Tester. . 460 Hopkins Reflux Condenser. . 165 Hopkins Vaccine Tubes ..138, 141 Horismascope 608 Horn, Gold Washing 298 Horn Pan Balance 48 Horn Scoops 436 Horn Spatulas 461 Horn Spoons 462 Hortvet Distilling Apparatus 199 Hortvet Tube 475 Hose, Rubber 430,431 Hose Connectors 308 Hosklns Chromel Triangles 606 Hoskins Electric Combustion Furnaces 260 Hosklns Electric Crucible Furnaces 263 Hosklns Electric Hot Plates 309, S10 Hoskins Electric Muffle Fur- naces 263. 266 Hosklns Pyrometers 421 Hot Air Blast, Electric 88 Hot Air Ovens 383-388 Hot Air Sterilizers 466-4BS Hot Blast Blowpipes 93 Hot Plates. Electric 308-310 Hot Plate with Flask Heater. 30* Hot Plates, Gas 117, 310 Hot Plates, Sand 434 Hot Water Funnels 25» Hour Glasses 434 Household Still 195 Household Thermometers . . . 494 Hubbard Specific Gravltv Bottle 24, 104 Huber Warming Table S^n Hughes Electric Ovens 382 Hulett Mercurv Still 191 Huyghenlan Eyepieces 344 Hydro-Carbon Burners .... 121. 122, 264, 260 Hydrogen Balloons 63 Hydrogen Determination Ap- paratus 277 Hydrogen Gas 274 Hydrogen Gas Generators 287, 288 Hydrogen Ion Concentration Apparatus 86 Hydrogen Ion Determination Apparatus 277 Hydrogen Sulphide Genera- tors 287 Hydrogen Sulphide Testers. . 281 282 Hydrometers,' All Kinds.'. 311-315 Hydrometers, Acid 311-313 Hydrometers, Asphalt 23 Hydrometers, Battery ....71, 813 Hydrometers, Milk 313, 314 Hydrometers. TTrlne 510 Hydrometer Carrying Case.. SI 4 Hydrometer Jars 183, 610 Hydrone 2 Hydrostatic Balance 357 Hydrotimeter 315 Hvgrodelk 316 Hvgrograph 317 Hygrometers 315-317 Hygrometers, Recording 317 Hygrometers (Sling Psych- rometers) 317 Hygrometer Wicks, Silk 317 Hypodermic Needles 486. 486 Hypodermic Syringes . . . .484, 485 Ice Bag 317 Ice Machines 3 Ice Shaver 817 Ideal Wire 622 Ignition Capsules ...127, 129, 162 Ignition Tubes 163, 427 Tier Cupel Machine 182 Illinois Butter Test Bottle. . . 367 Illinois Steel Co.'s Collecting Tube 286 Illinois Steel Co.'s Gas Bu- rette 283 Page Illinois Steel Co.'s Sulphur Rack 476 Illuminating Apparatus, Mi- croscope 345-347 Illuminating Burners ....117. 366 Illuminating Lamps.. 117, 345-347 Illuminator, Bull's-Eye Con- denser 345 Illuminators. Dark Field.... 344 Immersion Electric Heaters. 306, SOT Immersion Electrodes 397 Immersion Oil. Cedarwood... 34.ri Immersion Oil Bottles 100 Imperial Ammeters and Volt- meters 210 Incandescent Burners 117 Incandescent Gas Micro Lamp 117 Incandescent Lamps. .331, 345-347 Incineration Dish, Alundum. 162 Incineration Pan, Platinum.. 162, 409 Inclinator for Carboys 129 Incorridible Laboratory Bur- ner 114 Incubators, Bacteriological.. 318-325 Incubators and Parafflne Ovens 393-395 Incubator for Microscopes... 346 Incubator Heaters 321-322 Incubator Thermometer 495 India Rubber Tubing 430. 431 Indicator, Polarity 228 Indicators, Speed 462 Indicators for Speed of Cent- rifuges 135, 138. 141 Induction Coils 208. 399 Infusion Kettles 329 Injection Needles for Syr- inges 485 Injection Syringes 485, 486 Injector Burner 119 Ink, Waterproof Drawing.. 201 Ink for Writing on Glass.... 185 Inoculating Needles 326 Inocul'tin-r Needle Holder ..326 Insect Bottles 100 Insect Breeding Cages 326 Insect Nets 32« Insect Spreading Boards.... 328 Insect, Perforated, for Water Baths 480, 519 Insplssators, Gas 83 Instantaneous Water Heaters 307, 308 Instruments, Dissecting. . .189-194 Instruments, Drawing ...201-203 Instruments, Electrical, All Kinds 66-76, 205-229, 233, 234, 254, 260, 261, 263. 266, 267, 270, 271, 305-310, 403, 455 Instrument Cases. Dissecting 193 Instrument Sterilizers 465 Insulated Wire 521, 523 Insulating Tape 229 Insulators, Pyrometer Tube.. 420, 421 Interchangeable Electroscope, Lind 423 Internal Revenue Hydrome- ters 312 International Atomic Weights 144 International Electric Centri- fuges. .139-141, 142, 360, 446, 447 Interval Clock 152 Interval Timer 152 Invertebrate Dissecting Scis- sors 192 Inverted Specimen Jars .... 104 Iodine Coulometer, Wash- burn's 397 Iodine Number Determina- tion Flasks 248 Ions, Apparatus for the De- termination of the Migra- tion of 399 lonization Cell, Smith-Hale.. 399 Iron Chimney 123 Iron Crucibles 171, 174. 427 Iron Dishes 298, 433 Iron Evaporating Dishes.... 433 Iron Gauze 623 Iron Gold Washing Pans 298 Iron Levels, Mechanics' 333 Iron Machine Screws 436 Iron Molds 132. 366 Iron Mortars 367 Iron Ore Grinders 175-177 Iron Plumb Bob 412 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 541 Page Iron Retorts 174. 438 Iron Rings 428 Iron Rod 625 Iron Sand Baths 433. 4J4 Iron Scoops 432. 435 Iron Sheet 625 Iron Stands 477. 478. 480 Iron Supports 477. 478 Iron Triangles 504, 608 Iron Tripods 477. 505 Iron Weights 69. 60 Iron Wire 622 Iron Wire Gauze 623 Iron Wire Triangles 504. 505 Iron-Clad Relay 500 Jackson Specific Gravity Ap- paratus 133 Jackson Turbldimeter 507 Jam Jars 328 Japanese Lens Paper 333 Japanned Frame Thermome- ters 495 Jars. All Kinds 9. 11. 13. 16. 66-70. 72, 79. 80. 104. 105, 124, 153, 183. 326- 329 451 Jars. Acid • Jars. Anaerobic Culture 11 Jars. Animal 13 Jars. Aquaria 16 Jars, Battery 66-70, 72. 326 Jars. Bell 79. 80 Jars, Brain 327. 328 Jars. Calcium Chloride. . .124. 160 Jar. Chldlow Expansion 252 Jar. Chidlow Gas Collection.. 253 Jars, Culture 11 .Tirs. Dressing 327 Jars, Drying 124. 160 Jars. Expansion 252 Jars. Hydrometer 183 Jars, Inverted Specimen 104 Jars. Jam 328 Tars. Jellv 329 Jars. Lightning 328 Jars. Mixing 183. 327 Jars, Museum 327, 328 Jars. Nessler 153 Jar, Organic Matter 461 Jqr=. Percolator 327 Jars. Precipitating 327 .T^rs. Sample 103. 105. 328. 357 Jars. Screw Cap 103, 105, 357 Jars. Specimen 103, 105, 327. 328. 357 .Tqrs. Staining 328 .Tars. Stoneware 329 .Tqrs, Snre Seal 328 Jars. Waste 329 Jar Brushes 108, 109 Jetfer's Counting Plate 169 Jellv Jars 329 Jennine-s Kjeldahl Connect- ing- Bulb 371 .Tewplers' Rlowpines 92. 93 Jewelers' Screw Driver 437 Jewelers' Soldering Copper. . 460 Jewell Stills 196. 197 .Tewett's Reagent Bottles.... 103 Johnson Combustion Appara- tus 160 Johnson Combustion Boats.. 162 Johnson Combustion Train.. 160 Johnson Combustion Tubes. . 163 Johnson Combustion Tube Connectors 163 Johnson Digestion Apparatus 370 Johnson Drying Jar 160 Johnson Filtering Crucible.. 171 Johnson Flask 249 Johnson Kjeldahl Digestion Shelf 370 Johnson Milling Machine.... 160 Johnson Potash Bulb 160. 413 Johnson Rule 432 Johnson Sulphur Flask 249 .Toilet Flasks 248 Jones Boiling Point Appara- tus 401 Jones Sampler 432 Julian Color Comparison Tubes 153 Julian Crucible Tongs 508 Junkr-rs Gas Calorimeter . 2S4. 2SS K Page Kahlenberg's Gas Measuring Tube 289 Kalteyer's Forceps 256 Kawin Nickel Crucible 171 Keidel Blood Collector 83 Keldel Vacuum Culture Tube 84 Kekule Water Level 387 Kekule-Von Baeyer Atom Models 366 Kent Laboratory Shaking Ap- paratus 440 Kerosene Heated Furnace... 265 Kerosene Hydro-Carbon Burn- er 122 Kerosene Stove 122 Kerosene Testers. .. .314. 374-376 Kettles. Granlteware 130. 329 Keys. Contact 228. 229 King's Soil Tube 463 Klpp Gas Generator 287 Klrkbride Slide Forcep 256 Kirshbraun Adhesion Machine 18 Kit. Emergency 243 KItasoto Animal Holder 13 Kjeldahl Apparatus for the Determination of Nitrogen. 369-371 Kjeldahl Condensers 369. 370 Kieldahl Connecting Bulbs... 371 Kjeldahl Digestion Shelves.. 369-371 Kjeldahl Distilling Apparatus 370. 371 Kjeldahl Distilling Flasks... 248 Kjeldahl Flask Heater. Elec- tric 305 Knives. All Kinds 168. 190, 203, 253. 296. 329. 351. 355 Knife, Cartilage 190 Knife. Cork 168 Knife. Dough Mixing 253 Knife. Draw 203 Knife, Glass 296 Knives, Microtome 351. 355 Knives. Sectioning 351. 355 Knife Holders for Microtome Knives 353. 355 Knight Distilling Tube 200 Knorr Alkalimeter 129 Knorr Carbonic Acid Appara- tus 129 Knorr Extraction Flasks.... 230, 231. 247 Kober's Nephelometer 158 Koch Hot Water Funnel 258 Koch Safety Burners 114. 115 Koch Serum Oven Kohlrausch Conductivity Cells 396 Koblrausch Volumetric Flasks 250 Kolle Culture Flasks 1 Kuttner Micro-Colorimeter... 156 Kuttner Standard Color Tubes 85, 157 Kymograph 329 Labels. Dennlson 330 Labels, Micro Slide 330. 350 Label Books 330 Labelled Bottles 101-103 Laboratory Aprons 14 Laboratory Cement, DeKho- tinsky 130 Laboratory Clocks 152 Laboratory Gas Meters 284, 285. 289 Laboratory Grinders and Crushers 175-181 Laboratory Knives 329 Laboratory Lamps 94. 117. 120, 291, 331. 332. 345-347 Laboratory Microtomes 352 Laboratory Mills 177-181 Laboratory Scales 30-55 Laboratory Sleeves 14 Laboratory Sponges 462 Laboratory Tubing.. 117, 430. 431 Labruco Rubber Tubing.. 430. 431 Lacquer, Colorless 330 Lacquer. Gold 330 Lacquer Brush 109 Lactic Acid Funnel, Straus.. 259 Lactometers (Hydrometers).. 313 I^adenburg Distillation Flask 247 Ladle. Melting 330 Lamps, All Kinds 94. 117. 120, 155. 291. 331. 332. 345-347 Page Lamps, Alcohol .............. 1ZO Lamps, Blast ............ 119-12Z Lamp, Blowpipe ............ Lamp. Dangler .............. 1 Lamp, Davy's Safety ........ 332 Lamp. Daylight ..... 155. 345-347 Lamps, Glass Blowers' ....... 1 Lamp. Harcourt Pentane .... Lamps, Microscope ....... 345-34 Lamp, Pentane ............. 2 Lamp. Photometer Standard. 2 Lamp Chimneys ......... 114. 146 Lamp Cord ................. 621 Lamp Wicks. Alcohol ........ 120 Lancets for Blood ........... 86 Lautenschlaeger Hot Air Ster- ilizers ..................... 468 Leach Separatory Funnel Support .................. 479 Lead Assay Crucibles ---- 170. 1 Lead Capsules .............. 1 Lead Crucibles (Plumbago). 1 Lead Dishes ................ 1*7 Lead Pipe .............. 370. 525 Lead Sheet .................. 626 Lead Sl.ot .................. 332 Lead Shot for Cement Testers II Lead Tubing ................ 625 Lead Wire .................. 622 Leather Belting ............ 332 Leather. Evaporators for ..... 514 Leather Extraction Appara- tus ....................... 232 Le Bel-Hennlnger Distilling Tubes .................... 200 LeChateller Cement Bottle... 104 LeChateller Soundness Test Anparatus for Cement ..... 133 LeChateller Specific Gravity Bottle .................... 104 LeClanehe Batteries ......... ' Lecture Apparatus ...... 332. 8 Lecture Room Charts. .. .144. 145 Lecture Table Balance ...... 49 Lecture Table Galvano-Volt- Amm°ter ............... 2 Leeds Diamond Mortar ...... 366 . Lenses. Objectives .......... 8 Lenses. Pocket .......... 334. 335 Lens Holders ............... 1 Lens Paper. Japanese ....... 8 Le Page's Glue .............. 29S Lewis Instrument Sterilizer. 46! Lewis Paraffine Bath ........ 392 Letters, Steel ............... 1 M Letters. Stencil ............. 4«S Levels ....... 61. 333. 334, 482. 48S Level. Water, for Ovens ..... 387 Leveling Bulb for Gas Bu- rettes ................... '. 1 Leveling Screws ............ 3 Lever Action Air Pump ..... . 4 Levigated Alumina ......... 838 Levy Haemacytometers ..... 84 Library Paste .............. 3 Llebig Condensers .......... 165 Llebler Potash Bulb .......... 418 Lleblg-Dlttmar Potash Bulb. 413 Life Box. Slide .............. 349 Lifters. Section ............. 193 Lighter. Gas ................ 288 Lightning Jars .............. 328 Lie-tuning Sifter ............ 443 Lillie Parafflne Embedding Ovens ................. 394, 395 Lime Cylinders ............. 93 Limestone Testers ....... 129. 450 Lime-SulDhur Hydrometers.. 313 1 Lincoln Burette Clamp ...... 146 Lind Electroscopes ....... 423-425 Line. Fish .................. 165 Line. Mason's Chalk ......... 165 Linen Cord ................. 1 Linen Tape Measures ........ 486 Linen Testers ............... 334 Linen Thread ............... 501 Linen Twine ..... ........... 507 Lintner Pressure Bottle ..... 100 Lineman Capillary Electrode Tube ..................... 398 Liquid Measures ............ 336 List of Blowpipe Apparatus.93. 94 Liter Flasks ................ 249 Litmus Paper ........... 390. 391 Litmus Pencils .............. 395 Loaf Volume Apparatus ..... 255 Loeb and Nernst Migration Tube ...................... S99 542 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Page Logwood Paper 391 Lohnstein Saccharometers. . .. 509 Long Gas Electrode 398 Low Flask for Copper Deter- mination 248 Low Resistance Pyrometers.. 418-421 Low Temperature Burners... 114. 116 Low Temperature Incubators 324. 325 Low Temperature Thermome- ters 491 Low Temperature Thermo- stat 500 Low's Copper Assay Flasks.. 248 Loxol Cement 130 Lubrication Tester 377 Luer Syringes 484, 485 Lummer-Brodhun Photometer Sight Box 290 Lunge Apparatus.107, 247, 279, 372 Lunge Distillation Flask 247 Lunge Nitrometers 372 Lunge Tar Flask 247 Lunge Weighing Bottle 107 Luther Capillary Electrome- ter Tube 398 Luther Platinum Electrode.. 398 Machines, Cement Testing.... 131. 133 Machines, Centrifugal 141-143 Machines for Compression Tests on Cement 131 Machine, Cork Boring 167 Machines, Cupel 182 Machines for Making Gaso- line Gas 289 Machines, Sampling 432. 433 Machines, Shaking 438-440 Machine Screws 436 Mackey's Oil Tester 379 Magnalium Balance 40 Magnet 205 Magnet Wire 621 Magnetic Compasses ....164, 482 Magnification Table 348 Magnifiers, All Kinds 61, 169, 304, 334, 335 Magnifier for Balances 61 Magnifier for Brinell Tester.. 304 Magnifier for Colony Count- Ing 169 Magnifier Stands, Adjustable. 342 Mahler Bomb Calorimeters.. 127. 128 Mailing Cases for Micro Slides 350 Mailing Cases for Samples... 264 Mailing Tubes 336 Mallets 335 Manganese Determination Ap- paratus 153, 164 Manganese Tubes for Color Comparison, Camp's 153 Manila Rope 428 Mannheim Slide Rule 444 Mann-Junkers Gas Calorime- ter 286 Manometers 272. 273 Mantles for Berkefeld Filters 236 Manual for Petroleum In- spectors 377 Marchand Calcium Chloride Tubes 124 Marchand Drying Tubes 124 Marine Glue 298 Marker, Signal 501 Market Cream Score Cards... 363 Marking Gage 272 Marschall Acid Tester 356 Marschall Rennet Tester 362 Marsh's Arsenic Apparatus... 16 Marshall Apparatus for the Determination of Urea in Blood 87 Martin, Pennock and, Cru- cible 171 Mask, Face, Respirator 427 Masons' Chalk line 165 Mason's Fruit Jars 328 Mason's Hygrodeik 316 Mason's Hygrometer 316 Mason's Water Color Tube. . . 164 Massachusetts Institute Blast Burner 119 . Page Matches, Safety 336 Mats, Asbestos 17 Mats, Cork, "Suberlte". 168 Matthews Gas Machine 289 Matrass Holders 94 Mauls 335, 459 Maximum and Minimum Ther- mometers 495. 497 Mazda Incandescent Lamps.. 331. 345-347 McCall Aspirator 445 McCall's Capillarity Tubes 457 McCall's Mulch Cylinder 450 McCall's Percolation Appara- tus 451 McCoy Molecular Weight Ap- paratus 401 McLeod's Vacuum Gage 273 Measures, All Kinds 125 183, 272-274, 299. 336, 356, 432. 435, 486. 487 Measures for Acid in Milk Test 356 Measures. Caliper 125 Measures, Glass 183, 299 Measures, Graduated ....183, 299 Measures, Liquid 338 Measures. Meter and Yard... 432. 435 Measures, Rain 273 Measures, Tin 336 Measures. Wire 274 Measuring Appliances 125, 183, 272-275, 289, 299, 304, 336, 432, 435. 486 487 Measuring Bottle, Bockius... 100 Measuring Microscopes 343 Measuring Cones 273 Measuring Scales for Hard- ness Tester 304 Measuring Tapes 486. 487 Measuring Tubes for Gas. . . . 289 Meat Choppers 178, 179, 181 Mechanics' Levels 333 Mechanical Analysis Bottle.. 446 Mechanical Drawing Instru- ments 201-203 Medicine Droppers 4 Megohm Boxes 222 Meker Blast Burner 120 Meker Burners 115 Melting Crucibles ...170-172. 173 Melting Furnaces 264. 266 Melting Ladles 330 Melting Point Apparatus.... 18, 23. 336 Melting Point Apparatus for Tar and Pitch 18, 23 Melting Point Flask 248 Melting Point Testers for Wax 377, 378 Melting Point Tube 336 Mendele.leff Charts of the Elements 144 Meniscus Reader for Burettes 113 Manzles' Molecular Weight Apparatus 401 Mercurial Barometers ....64. 65 Mercury Distilling Apparatus 199, 427 Mercury Manometers 273 Mercury Pipettes 405 Mercury Plumb Bob 412 Mercury Reservoirs 110 Mercury Retorts 427 Mercury Still. Hulett 199 Mercury Wells for Armored Thermometers 492 Metal Cases for Thermome- ters 492 Metal Frame Thermometers. . 496 Metal Model Sextant 438 Metal Resistance Table 528 Metal Scale Thermometers... 495 Metal Testers, Hardness. .303-305 Metal Travs 604 Metallic Tapes 486, 487 Metallic Thermometer 49« Metallic Tubing, Flexible 431 Metallographlc Apparatus.... 337, 338 Metallographlc Emery Paper. 3 Metallographlc Grinders .... 337 Metallographlc Hack Saw. . . . 337 Metallographlc Polisher 337 Metallographic Polishing Alumina 338 Meteorological Set 338 Meteorological Shelter 338 Meters, Air 12, 285, 289 Pase Meters, Electric 209-213 Meters, Gas 284, 285. 289 Meters, Gas, for Junkers Ca- lorimeters 284, 285, 289 Meters, Turbidity 159. 507 Meter Measures 432, 436 Meter Sticks 435 Meter Stick Clamps 150 Methane Determination Ap- paratus 27fi Metric Charts 145 Metric Measures, Liquid 336 Metric Rules 432 Metric Tables 145 Metronomes 338 Metropolitan Argand Burner, Carpenter's 292 Meyer Bulb Tubes 8. 476 Meyer Sulphur Apparatus.... 476 Meyer Vapor Density Appa- ratus 511 Mica Chimney 114 Mica Sheet 525 Mice Holders 13 Micro Burners, Bunsen's 114 Micro-Colorimeter 156 Micro Cover Glasses 350 Micro Labels for Slides.. 330. 350 Micro Lamps 345-347 Mlcro-Saccharimeter 86 Micro Slides 348. 34fl Micro Slide Boxes 349. 350 Micro Slide Cabinets 349 Micro Slide Labels 330. 350 Micro Slide Mailing Cases. . . . 350 Micro Slide Trays 350 Micro Warm Stages 350 Micrometers, Eyepiece. .. .347. 520 Micrometer, Stage 347 Micrometer Calipers 125, 391 Micrometer Gages 125. 391 Micrometer Microscopes. .304. 343 Micrometer Oculars 344 Microscopes and Accessories. 339-351 Microscope, Demonstration. . . 341 Microscopes, Dissecting. . 341, 342 Microscopes, Measuring. .304, 343 Microscopes. Micrometer. 304. 343 Microscope, Simple 341 Microscope Eyepieces 344 Microscope Illuminators. . 344. 345 Microscope Incubator. Elec- tric 345 Microscope Lamps 345-347 Microscope Lamp Distribut- ing Box 347 Microscope Micrometers 347 Microscope Nosepieces 348 Microscope Objectives, Achro- matic 348 Microscope Support 343 Microscopic Slide Boxes 349 Microscopic Slide Forceps.... 256 Microscopic Slide Mailing Cases 350 Microscopical Cover Glasses. . 350 Microscopical Labels ....330. 350 Microscopical Object Slides. . 348. 349 Microscopical Slide Boxes.... 34^> Microtomes and Accessories.. 351-355 Migration of Ions, Apparatus for 39!) Migration Tubes 399 Milk Analysis Apparatus. . 35R-364 Milk Analysis Bottles 357, 358 Milk Bottle Brushes 109 Milk Capsules 129. 187 Milk Centrifugal Machines... 359-361 Milk Dishes 129, 187, 358. 409 Milk Dish. Platinum 409 Milk Extraction Apparatus.. 358 Milk Hydrometers 313. 314 Milk Jar (Bottle) 357 Milk Pipettes 362 Milk Pipette for Counting Bacteria 404 Milk Record Charts 358 Milk Test Bottles 357. 358 Milk Test Brushes 109 Milk Tester or Pioscope, Hee- ren's 362 Milk Testers, Centrifugal. 359-Sfil Milk Testing Apparatus. .35(5-364 Milk Testing Balances. 41, 47, 357 Milk Tube for Centrifuge 135, 138. 141 CENTRAL SCIENTIFIC CO., CHICAGO. U. S. A. 543 Page Mills, Assayers' 175-181 Mills. Grinding 175-181 Mills. Rolling 180 Mill, Sugar Cane 179. 181 Miller Parafflne Bath 393 Mllliammeters and Ammeters 209-213 Milling Machine, Johnson.... 160 Millivoltmeters and Voltme- ters 209-213 Mine Air Analysis Apparatus 276. 277 Mine Air Testers 276 Miner's Horn 298 Miner's Lamp 332 Miner's Washing Pan 298 Minerals for Blowpiping. . . . 94 Minerals. Radio-Active...425. 426 Mineral Collections 364. 365 Mineral Oil Distillation Ap- paratus 374, 378 Mineral Specimens 364, 365 Mineralogical Collections.364. 365 Mineralogical Hammers. . .94. 303 Mineralogical Specimen Trays 365 Miniature Incandescent Lamps 331 Miniature Microscope Lamp. . 346 Minimum Thermometers. 495, 497 Minot Micro Slide Cabinet... 349 Minute Glasses 434 Miquel Culture Flasks 182 Mirrors for Galvanometers.. 207 Mitre Box, Olmstead's 366 Mitscherlich Eudiometer .... 230 Mitscherlich Potash Bulb 413 Mittens, Asbestos 297 Mixing Bottles 183, 327 Mixing Cylinders, Precision.. 183 Mixing Jars 183. 327 Mixing Pipettes for Haemacy- tometers 85 Mixing Scoops 432. 435 Models, Atom 366 Models, Valence, Mead's 366 Mohr's Alkalimeters 129 Mohr's Burettes 111. 112 Mohr's Carbon Dioxide Appa- ratus 129 Mohr's Clamps 147 Mohr's Pinchcocks 147 Mohr's Pipettes 405. 406 Mohr's Potash Bulb 413 Moist Chambers 181 Moisture Absorption Appara- tus 445 Moisture Balances. . .42, 49, 54. 55 Moisture Determinator for Gas 285 Moisture Dishes 187 Moisture Equivalent Centri- fuge 447 Moisture Flasks 248 Moisture Graduates 183. 301 Moisture Ovens 383-388 Moisture Scales 42, 49. 54, 55 Moisture Test Cylinders. 183. 301 Moisture Testers 301. 361 Moisture Tester Thermome- ters 302. 492 Molds for Asphalt 23 Molds, Briquette, Asphalt.... 23 Molds, Briquette, Cement.... 131 Molds for Cement 131. 132 Molds, Cubical for Asphalt.. 23 Molds, Cubical for Cement... 132 Molds, Cupel 182 Molds, Pitch 22. 23 Molds. Pouring 366 Molds for Soil 451 Molding Machines, Cupel.... 182 Molecular Weight Determina- tion Apparatus 400, 401 Monkey Wrenches 523 Monochromatic Illuminators. 366 Morse Calibrating Burettes.. 112 Mortars, All Kinds 366. 367 Mortar Grinder, Steel 177 Motors, Electric. .126, 128, 214-216 Motors, Variable Speed 126, 128, 214, 373 Motors, Water 368 Motor Countershaft 216 Motor Generators 217. 218 Motor Speed Reducing Gear. 216 Mounts, Riker Botanical 95 Mounts. Riker Specimen 461 Mounting Boards. Botanical. . 95 Mounting Cells, Slide 349 Page Mounting Paper, Botanical. . 95 Mouse Jars 13 Mouth Pieces for Blowpipes.. 92 Muencke Blast Apparatus. . . 92 Muencke Blower 92 Muencke Filter Pump 242 Muencke Gas Analysis Appa- ratus 279 Muencke Gas Washing Bottle 294 Muffles, All Kinds 265-269. 367 Muffles, Alundum 367 Muffles, Clay 367 Muffles, Silica 367 Muffle Furnaces 263. 265-269 Muffle Furnace, Gary's 269 Muffle Furnaces. Fletcher.... 265 Muffle Furnaces, Hoskins Electric 263. 266 Muffle Furnaces, Multiple Unit Electric 267 Muffle Furnace, Wlessnegg. . 269 Muffle Scrapers 436 Mulch Cylinders 450 Mullen's Paper Tester 391 Multiple Tube Burners 115, 116. 119 Multiple Unit Electric Com- bustion Furnaces 261 ' Multiple Unit Electric Cru- cible Furnace 263 Multiple Unit Electric Hot Plates 310 I Multiple Unit Electric Muffle Furnaces 267 i Multiple Unit Electric Organ- ic Combustion Furnace.... 261 Multiplex Slide Holder 350 Multiplex Slide Rule 444 Murrill's Gas Pressure Regu- lator 294 Museum Jars 327. 328 Muslin Buffing Wheels.. .412. 413 Muter's Oil Tube 378 Myers Colorimeter 157 Nafis' Acid Dippers 356 Nafis' Acid Tester 356 Nafis' Salt Tester 363 Nafis1 Stirring Rod 357. 363 Nafis' Tester for Test Bottles 363. 364 Nail Sets 368 Naples Jars 328 Naples Paraffine Bath 393 Naples Staining Jars 328 National Fuller Battery 68 National Rheostats 224 Natural Gas Analysis Appa- ratus 277 Natural Gas Burners 118 Nead's Valence Models 366 Nebraska Soil Auger 452. 453 Needles, Dissecting 190 Needles, Gilmore 132 Needles, Hypodermic ....485. 486 Needles. Inoculating 326 Needles, Syringe 485. 486 Needle Apparatus, Vicat 133 Needle Holders 190. 326 Nernst Migration Tube 399 , Nesbitt Carbon Combustion Bulbs 8, 9 Nessler Cylinders 153 Nessler Cylinder Support.... 154 Nessler Tubes 153 Nessler Tube Support 154 Nets for Foot Blowers 88 Nets for Insects 226 Neubauer-Bfirker Haemacy- tometer 84 New York Board of Health Distilling Apparatus 520 New York Testing Labora- tory Drying Ovens 21 New York Testing Labora- tory Penetrometers 24 Nicholson Hydrometers 316 Nlchrome Triangles 505 Nichrome Wire Gauzes 523 Nickel Alloy Wire 522 Nickel-Chrome Gauze 523 Nickel Chromium Triangles.. 505 Nickel Chromium Pyrometer Protecting Tubes 420 Nickel Crucibles 171 Nickel Crucible Tongs 502 Nirkel Dishes 187 Nickel-Plated Copper Beakers 78 Page Nickel Tongs 602 Nickel Weighing Scoop 62 Nickel Wire 522 Nickel Wire Gauze 523 Nickeled Burette Clamp 146 Nicol Specific Gravity Tube. . 104 Ninhydrin 82 Nippers 411 Nipples for Air Pumps 471 Nitrogen Apparatus, Van Slyke's 372 Nitrogen Bulbs 371 Nitrogen Determination Ap- paratus 153. 369-373 Nitrogen Filled Thermome- ters 491 Nitrogen Gas 275 Nitrogen, Urea and Ammonia in Urine, Folin Apparatus for 608. 509 Nitrometers 371. 372 Nitrous Oxide Gas 275 Nixtamal Grinding and Pul- verizing Mill 178 Nodon Valve 219 Non - Corrodible Laboratory Burner 114 Non-inductive Resistances... 227 Normal Burettes 112. 113 Normal Differential Ther- mometers. Beckmann's .... 493 Normal Elements, Cadmium. 397 Normal Flasks 250 Normal Graduates 183 Normal Mixing Cylinders.... 183 Normal Pipettes 406 Normal School Crucibles. Skidmore's 174 Normal Solution Flasks 250 Norris Potash Bulb 413 Norris Sulphur Apparatus... 476 Nosepieces for Microscopes.. 848 1 Novy Anaerobic Culture Ap- paratus 11 Novy Cover Glass Forceps... 256 Novy Culture Jars 11 Numbers, Steel 186 Objectives, Achromatic 348 Objectives for Microscopes. . 348 Ocular Micrometers 344 Ocular Micrometer Disks.... 347 Oil of Cedar 345 Oil for Pumps 416 Oil Burette 378 Oil Burners 122 Oil Cans 37S Oil Decanting Tube 378 Oil Distilling Apparatus. 374. 378 Oil Feeder for Flotation Ma- chine 251 Oil Freezer, Tagliabue 377 Oil, Fusel, Determination Ap- paratus 271 Oil Heated Parafflne Ovens . . 394. 395 Oil Measuring Device, Auto- matic 302 Oil Sample Bottles 100 Oil Samplers 379 Oil Sampler and Water Indi- cator 380 Oil Stills 198. 199, 374, 378 Oil Stones 373 Oil Tables. Tycos 378 Oil Testing Apparatus. .. .373-380 Oil Testing Machine, Thurs- ton 377 Oil Thermometers. . . .495. 496, 497 Oil Tubes for B. S. in Petro- leum 135. 140. 374 Oil Tubes for Centrifuges... 135, 140, 374 Oil Tube. Muter's 378 Oiled Silk 443 Ointment Pots 328 Oldberg's Percolators 395 Olmstead's Mitre Box 366 Olsen's Testing Machines for Cement 131. 133 Opaque Fused Silica Arsenic Tube 17 Opaque Fused Silica Capsules 162 Opaque Fused Silica Carbon Flask 247 Opaque Fused Silica Casse- roles 130 544 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Page Opaque Fused Silica Combus- tion Boats ................ 162 Opaque Fused Silica Combus- tion Tubes ................ 163 Opaque Fused Silica Cru- cibles ..................... 174 Opaque Fused Silica Evapo- rating Dishes ............. 186 Opaque Fused Silica Flasks.. ...................... 246, 247 Opaque Fused Silica Rods... 443 Opaque Fused Silica Sugar Dish ...................... 188 Opaque Fused Silica Tannin Dish ..................... 188 Opaque Fused Silica Test Tubes ................. 163. 488 Opaque Fused Silica Tubing. 163. 443 Optical Pyrometer, Scimatco 421. 422 Optical Pyrometer, Shore's.. 422 Ore Crushers 175 Ore Grinders 176-177 Ore Samplers 432. 433 Ore Sampling Pans 433 Organic Analysis Furnace.. 261 Organic Combustion Furnace 261 Organic Matter Determina- tion Apparatus 450 Organic Matter Jar 461 Orsat Gas Analysis Appara- tus 277, 279-281 Orsat Gas Bulbs 279. 428 Orsat-Fischer Gas Analysis Apparatus 279 Orsat-Lunge Gas Analysis Apparatus 279 Orsat-Muencke Gas Analysis Apparatus 279 Osborne's Lecture Apparatus. 333 Osmosemeter 401 Ostwald Apparatus ..396-399, 403 Ostwald Calomel Normal Electrode 397 Ostwald Capillary Electrom- eter Tubes 399 Ostwald Conductivity Cell... 396 Ostwald Gas Electrodes 398 Ostwald Pipettes 403-405, 508 Ostwald Pipette for Folin Apparatus 508 Ostwald Toluol Regulators.. 501 Ostwald Viscosity Determina- tion Outfit 403 Outfit for Blowpipe Analysis 94 Ovens for Asphalt Testing... 21, 23, 387 Ovens, Baking 381. 382 Ovens, Constant Temperature 383-385 Ovens, Drying 383-388 Oven for Melting Point of Hard Pitch 21. 23 Ovens, Paraffine Embedding. 393-395 Ovens, Vacuum Drying 388 Oven Thermometer, Bake... 255. 493 Overflow Pipettes 404 Oversleeves 14 Oxone 288 Oxygen Bomb Calorimeters. 127. 128 Oxygen Bomb Calorimeter. Adiabatic 128 Oxygen Cylinders 276 Oxygen Determination Appa- ratus 277, 279-283. 293, 294 Oxygen Flasks 248 Oxygen Gas 275 Oxygen Gas Generators. .288. 427 Oxygen Generating Appara- tus 288, 427 Oxygen Generating Retorts. . 427 Oxygen Tanks 275, 288 Oxygen Tank Gages 275 Oxyhydrogen Blowpipes 93 Ozonator, Electric 389 Ozone Apparatus, Siemen's... 390 Ozone Tube 390 Page Palm Glass 414 Palm Oil Soap 354 Palmquist Gas Analysis Ap- paratus 279 Pans for Balances 61 Pans, Baking 263 Pan for Briquettes (Cement Testing) 132 Pan, Cement 132 Pans, Dissecting 190 Pan, Gold Washing 298 Pan, Grain Sample 302 Pans, Incinerating, Platinum 409 Pans for Ore Samples 433 Pans, Sample 302 Pans, Sifting 441, 442 Pans, Soil 445, 461. 455 Pans, Washing 253. 298 Pantograph 390 Paper, All Kinds 17, 95, 96, 169. • 185, 202, 228, 230, 238-241, 329, 333, 337, 361, 380, 390. 391 Paper, Adams Fat Extracted. 390 Paper, Asbestos 17 Paper. Blue Print 390 Paper, Carborundum ........ 390 Paper, Congo Ked 390 Paper, Cross Section 169 Paper, Dialyzing 186 Paper, Drawing 202 Paper, Drying, Botanical. . .95. 96 Paper, Emery 230 Paper, Emery, Metallographic 337 Paper, Fat Extracted for Milk Analysis 241, 361 Paper, Filter 238-241 Paper, Glazed 390 Paper, Glazed for Kymograph 329 Pads, Asbestos 17 Pail for Waste 390 Pails, Weighing 284 Palladium Tube for Gas Anal- ysis 290 Paper, l_,ens, Japanese ....... 333 Paper, Litmus ........... 390, 391 Paper, Logwood ............ 391 Paper, Mounting, Botanical.. 96 Paper, Paraffine ............ 391 Paper, Parchment .......... 391 Paper, Plant Description ..... 96 Paper, Pole indicating ....... 228 Paper, Pressing, Botanical. 95, 96 Paper, Sand ................ 391 Paper, Turmeric ............ 391 Paper, Water Indicating ..... 38U Paper, Wrapping ........... 391 Paper Bags ................. 391 Paper Boxes ............ 108, 241 Paper Racks ................ 391 Paper Scales ................ 435 Paper Scale Thermometers.. 496 Paper Shears ............... 440 Paper Tester. Mullen ........ 391 Paper Testing Machines. .391, 489 Paper Thickness Gages.. .391. 392 Paraffine Candles ........... 507 Parafnne Embedding Baths.. ...................... 392, 393 Paraffine Embedding Box ---- 354 Paraffine Embedding Ovens.. ....................... 393-395 Paraffine Embedding Table.. 354 Paraffine Receptacle for In- cubators .................. 39i Paraffined Paper ............ 390 Parallel Jaw Clamps ........ 150 Parallel Rules .............. 202 Parker's Deflagration Spoon. 18< Parker's Glass Cutting Tool. 295 Parr Adiabatic Calorimeter.. 12i Parr Carbon Apparatus ...... 12( Parr Coal Calorimeters. . .126-128 Parr Gas Calorimeter ........ 283 Parr Oxygen Bomb Calorime- ter ........................ 12 Parr Standard Calorimeter.. 121 Parr Sulphur Photometer.... 121 Parr Weighing Bottle ....... 10' Paste, Library .............. 334 Paste, Soldering ............ 46 1'aste Board Boxes ....... 108. 241 Pasteur-Chamberland Filter Cylinders ................. 237 Pasteur - Chamberland Pres- sure Filters ........... 236. 23 Pasteur Dishes ............. 18 Pasteurizing Outfit .......... 36 Pasteurizing Thermometer . . 36 Pastille Press ........... 128. 414 Pauli's Calomel Electrode... 397 Pauly's Receiver ............ 426 Payne's Platinum Dish ...... 409 Pebble Mills ............ 179, 180 'eerless Automatic Water Stills 195 'eligot Calcium Chloride Tubes 124 eligot Potash Bulb 413 ellet Press for Calorimeter Work 128, 414 'ens, Drawing 202 'encils, All Kinds 202. 395 'encils, Drawing 202 encils, Litmus 395 'encils. Wax 395 'encil Brushes 109 'encil Compasses 163 'encil Sharpener 395 'enetration Needle, Asphalt. 24 'enetrometers, All Kinds.... 24, 25, 133. 451 ^enetrometers, Asphalt ...24. 25 enetrometer. Schutte 25 ^enetrometer. Soil 451 enetrometer, Vicat's for Ce- ment 133 enfield Application Goniom- eters 298, 299 enfield Contact Goniometers 298, 299 ennock and Martin Crucible 171 ennock and Martin Sulphur Apparatus 171 Pensky-Martin Flash Point Tester 376 ensky-Martin Oil Tester.... 376 Dentane Lamp, Harcourt.... 291 Pentane Thermometer for Low Temperatures 491 Peptone, Silk 82 Pepys-Berzelius Gas Holders. 288 Dercentage Scale for Cement 46 Percentage Tube for Haemo- tokrit 134 Percolation Apparatus, Mc- Call's 451 Percolators 395 Percolator Bottles 327 Percolator Jars 327 Perforated Disks for Caldwell Crucibles 172 Perforated Porcelain Plates for Funnels 238 Periodic System Chart 144 Pestle, Rubber 451 Petterson-Palmquist Gas Ap- paratus 279 Petri Dishes 181 Petri Dish Covers. Porous Clay 181 Petri Dish Holders 181 Petroleum Inspectors' Man- ual 377 Petroleum Testers 373-380 Petrological Collections. .364, 365 Phenol Tube 259 Phenol-Sulphone - Phthalein Ampoules 156 Phillips Beakers 246 Phosphor Bronze Ribbon.... 525 Phosphor Bronze Sheet 525 Phosphorescent Minerals . . .. 426 Phosphoric Acid Flask, Volu- metric 250 Phosphorus Determination Apparatus 134-141, 248, 427 Phosphorus Electric Centri- fuges 135-141 Phosphorus Flasks 248 Phosphorus Tubes. Blair's Reductor 427 Phosphorus Tubes, Goetz.135. 141 Photographic Trays 504 Photometers and Accessories. 126, 155, 290. 291 Photometers. Gas 290. 291 Photometer, Hess-Ives 155 Photometer, Sulphur, Parr... 126 Photometer Sight-Box 290 Photometer Standard Incan- descent Lamp 331 Photometric Candles 292 Physical Balances. ...44, 49, 61-55 Physical Chemistry Appara- tus 396-403 Physiological and Clinical Apparatus 82-87 Piano Wire 522 Picks, Mining 303 Pincnometers 24. 104. 105 Picture Wire 522 Pill Boxes 108 Pillsbury Boxes 349 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 545 Paee Pilot Flame Burner 113 Pins, Insect 326 Pins, Ordinary 404 Pincers 256 Pinch Clamps 147 Plnchcocks. Mohr's 147 Pinning Forceps 2 Pioscope, Heeren's 362 Pipe, Block Tin 526 Pipes. Clay 404 Pipe. Lead 370. 625 Pipe Stem Triangles 503. 504 Pipe Wrench. Stillson's 523 Pipettes. All Kinds 85, 87, 107. 134, 279. 293. 294, 366, 362, 404-406. 475. 508 Pipette, Acid. Automatic 356 Pipettes. Automatic 87. 404 Pipettes, Blood. Wright's.... 87 Pipettes. Blood Counting 85 Pipette for Centrifuge 134 Pipettes, Certified 406 Pipette, Comer's Automatic. . 87. 404 Pipettes, Dropping 87. 404 Pipettes, Explosion 293. 294 Pipettes, Gas 293. 294 Pipette, Glucose 404. 476 Pipettes, Haemacytometer. . . 86 Pipettes, Mercury 405 Pipettes, Milk, Babcock 362 Pipettes, Orsat 279 Pipette, Ostwald Calibrating. 404 Pipette, Ostwald for Folin Apparatus 508 Pipette. Ostwald Viscosity... 403 Pipettes, Serological 405 Pipettes. Sugar 404. 475 Pipettes, Transfer 405 Pipettes. Viscosity 403 Pipettes, Volumetric 405 Pipettes, Weighing 107 Pipette Bottle 406 Pipette Boxes 406 Pipette Brush 109 Pipette Electrode 397 Pipette Rest 406 Pipette Support 406 Pitch Molds 22. 23 Pitch Testers 18-25 Pitchers. Acid 9 Pitot Tube 272 Planes 406 Plant Bell Jars 79. 80 Plant Description Paper 96 Plant Physiology Apparatus.. 407 Plant Presses 95. 96 Plantamour's Hot Water Fun- nels 258 Plasticity Apparatus 451 Plates. All Kinds 16. 94. 132, 168. 169. 175. 181. 185. 203, 238. 253, 255, 299, 300. 306. 308-310, 407, 408, 416 Plates for Air Pumps 416 Plate. Arsenic 16 Plates. Beaker Covers 407 Plate. Cement 132 Plate. Color Reaction 408 Plates. Colored Glass 408 Plates, Cork 168 Plates. Counting Bacteria... .168. 169 Plates, Crushing 175 Plates for Desiccators 185 Plate. Draw 203 Plates, Germinating 299. 300 Plate. Glass, for Cement 132 Plate. Glass, for Slick Test.. 253 Plate. Gluten 255 Plates. Hot. Electric. 306. 308-310 Plates, Hot. with Flask Heat- er 306 Plates. Hot. Gas 117. 310 Plates, Perforated, Porcelain for Funnels 238 Plates, Petri, Culture... 181 Plates. Porcelain 185. 238. 253 Plates, Porous 299. 408 Plates, Streak 17. 94 Plates, Suberlte 168 Plates. Zinc 255 Plate Glass Plates 132. 407 Plate Rheostats 226 Plate and Rubber. Iron 175 Platinoid Wire 522 Platinum Wire 93. 256. 408-411. 502 Platinum Blowpipe Tips 93 Platinum Crucibles 408, 409 Page Platinum Electrodes SSI. 410 Platinum Electrode Dishes.. 409 Platinum Forceps 94. 256 Platinum Holders 326 Platinum Needles 386 Platinum Weights 55-57 Platinum-Rhodium Couples for Brown Pyrometers 420 Platinum Thermo-Couples. . . 420 Platinum Tipped Forceps. 94. 256 Platinum Tipped Tongs 502 Platinum Wire for BIowplp- ing 94. 411 Plattner Blowpipes 93 Plattner Blowpipe Apparatus 93. 94 Plattner Diamond Mortar. . . . 366 Plattner Hammer 94 Plattner Scale 94 Pliers 411. 412 Plotting Paper 169 Pings for Electrical Connec- tions 227. 228 Plugs. Fuse 227 Plumb Bob. Iron 412 Plumbago Crucibles 172 Plunge Batteries 69 Pneumatic Troughs 506 Pocket Ammeters and Volt- meters 209 Pocket Carrying Case. Hy- drometer 314 Pocket Flash Lamp 331 Pocket Hand Book of Blow- pipe Analysis 94 Pocket Knives 329 Pocket Level. Brass 333 Pocket Magnifiers 334. 336 Pocket Rules 432. 436 Pocket Screw Driver 437 Pocket Thermometers 492. 494. 497 Polar. Cenco-, Water Stills.. 196. 197 Polar Co-ordinate Paper 169 Polarity Indicators 228 Policemen. Rubber 429 Polisher for Metal Specimens 337 Polishing and Grinding Ma- chines 336. 337 Polishing Heads 412. 413 Polishing Material ?3fl. 336-338, 368. 390. 412. 413 Polishing Wheels. Felt... 412. 413 Porcelain Acid -Dishes 185 Porcelain Arsenic Plate 16 'Porcelain Rail Mills 179.180 Po-velain Rails for Mills 180 , Porcelain Beakers 78 Porcelain Bowl 107.253 Porcelain Burner 114 Porcelain Capsules. . .129. 162. 187 Porcelain Casseroles ....129. 130 Porcelain Combustion Boats.. 161 Porcelain Combustion Cap- sules 129. 162 Porcelain Combustion Tubes. 1S3 Porcelain Cones 238 Porcelain Crucibles. . .20. 172. 173 Porcelain (^ups 253. 484 Porcelain Desiccator Plates. . 185 Porcelain Evaporating Dishes 186. 187 Porcelain Filter Cones 238 Porcelain Filter Cvllnders... 238 Porcelain Filter Disks 238 Porcelain Filter Flasks 237 Porcelain Funnels 258 Porcelain Jars for Ball Mills. 179. 180 Porcelain Mills 179.180 Porcelain Mortars 367 Porcelain Pipette Rest 406 Porcelain Plates. 1S5. 238. 253. 408 Porcelain Plate for Color Re- actions 408 Porcelain Plates for Desicca- tors 1«5 Porcelain Plates for F""nels. 23S Porcelain Pyrometer Tubes.. .421 Porcelain Rings 428 Porcelain Soatulas 461 Porcelain Spoons 462 Porcelain Swimming Cups... 484 Porcelain Tubes 163. 421 Porous Covers for Petri Dishes 181 Porous Cups, Battery 6fl. 68 Porous CUDS or Cells 66. 68 Porous Filters 237. 238 Porous Plates 408 Page Portable Ammeters and Volt- meters 209-212 Portable Electric Testing Set 2 Portable Galvanometers .... 206 Porter's Electric Motors..... 214 Posts, Binding 75 Potash Bulbs 413. 414 Potato Culture Tubes 488 Potato Cutter. Ravenel 414 Potentiometers 222. 223 Pots, Acid 9 Pouring Molds 366 Power Mills and Grinders... 175-181 Power Sieve Shakers. .. .442. 443 Precipitating Jars 327 Precision Burettes 112. 113 Precision Flasks. Volumetric 250 Precision Graduates 183 Precision Hydrometers ...311-31 Precision Microtome 353 Precision Mixing Cylinders.. 183 Precision Pipettes 406 Precision Thermometers. .491-^95 Precision Urlnometers 510 Preparation Dishes 188 Preparation Jars 326-328 Prescription Balances 39. 40. 42. 43. 47. 51. S4 Prescription Weights Preservation Jars 326-328 Press for Calorimeter Work. 128. 414 Press. Filter 248 Presses. Flower 95. 96 Press for Herbs 414 Press. Laboratory 414 Press. Pastille 128. 414 Pr»ss. Pellet for Calorimeter Work 128. 414 Presses. Plant 95. 9S Press. Tincture 414 Pressing Paper. Botanical. .95. 96 Pressure Blowers 89-9? Pressure Bottles 100 Pressure Cookers. Sterilizers 28 Pressure Filter Apparatus... 236. ?37 Pressure Oages 272-27 Pressure Gas Bags 282 Pressure Pumps. . .89-92. 414. 424 Pressure Regulators. Gas.... 28. 274, 276. 284. 294. 501 Pressure Regulator. Gas. for Thermo-Regulators 294 Pressure Sterilizers 26-29 Pressure Tanks 90, 92. 414 Pressure Tube. Osmotic 401 Pressure Tubing 431 Primarv Batteries 66-70 Prince Rupert's Drops 4 Probang 110 Probes 193 Proofing Cabinets ?! Prospectors' Hammers ....94. 303 Protecting Cases for Pyrome- ters 419. 420 Protecting Pyrometer Tubes. 420. 421 Protractor and Goniometer. Penfield 298 P=vf-hrom"ters. Sline 317 Pudding Trav for Soils 4K7 Pukal. Filter Balloon 237 Pulleys on Support for Trans- mission 216 Pulp Balances 39. 40 Pulse or Palm Glass 414 Pulverizers 17S-181 Pulverizing. Grinding and Crushing Apparatus ...175-181 Pumns. All Kinds ..9. 89-0'. 242. 243. 414-416. 424 Pumps. Acid 9 Pum^s. Air. Mechanical. 89-91. 414 Pumps. Blast 89-9? Pumps. Compression for Gases 414 Pumps. Filter 242. 243 Pumps.' "Pressure. .89-92. 414. 424 Pumns. R'iction. .242. 243. 414-416 Pumps. Suction and Pressure 89-92, 414. 424 Pumps. Vacuiiti 89-92. 24? 243, 414-416. 424 Pumns. Water P.last 99. Pumps. Water Filter 242. 243 Pump Oil 416 I Pump Platf-s. Air 416 i Purlnometer, Hall's 508 546 CENTBAL SCIENTIFIC CO., CHICAGO, U. 8. A. Push Buttons for Electric Bells 81 Pycnometers 24, 104, 105 Pyrex Glass Combustion Tubes 163. 297 Pyrex Glass Combustion Tub- ing 297 Pyrex Glass Flasks 244-249 Pyrex Glass Test Tubes 488 Pyrometers, All Kinds. .. .417-423 Pyroscope, Shore's Pyrometer 422 Quadrant 483 Quadruple Microscope Lamp. 347 Qualitative Filters 238-240 Quantitative Filters 240. 241 Quartz Apparatus, Transpar- ent 17, 78, 162. 163, 173, 187, 249. 421. 42R. 488 Quartz Arsenic Tube 17 Quartz Beakers 78 Quartz Combustion Boats. . . . 162 Quartz Combustion Tubes. . 163 Quartz Crucibles 173 Quartz Dishes 187 Quartz Flasks 249 Quartz Laboratory Utensils.. 78. 162. 163, 173, 187, 249. 421. 428. 488 Quartz, Pyrometer Tubes 421 Quartz Retorts 428 Quartz Test Tubes 488 Quartz Triangles 505 Quartz Tubes 163, 488 Quevenne Lactometers (Hy- drometer) '. . 313 Quill Handle Brushes 109 Quinine Bottles 97 Qulxo Cement 130 R. R. Alundum 162 Racks, All Kinds 243, 350, 362. 391, 476. 477, 479-481, 517, 519 Racks, Filter 243 Racks, Paper 391 Racks for Soil Tubes 460 Racks for Staining Slides... 350 Rack for Sulphur Apparatus. 476 Racks for Test Bottles 362 Racks for Test Tubes 480, 481. 517. 519 Radial Burners, Fletcher.... 116 Radiation Pyrometers, Thwlng 422. 423 Radio-Active Apparatus. .423-426 Radio-Active Minerals... .425. 426 Radio-Chemistry Apparatus.. 423-426 Radio Microscope Lamps.... 345 Radiometer 426 Radioscope 426 Radium Apparatus 423-426 Radium Electroscopes ...423-425 Radium Sninthariscope 426 Rafter's Counting Apparatus 520 Rain Gages 273 Rake, Cupel 182 Ralston's Still 195 Rammer for Briquettes (Ce- ment Testing) 133 Rare Metal Pyrometers. . .417-419 Rat Tail Files 235 Ratchet Screw Driver 437 Rauvier's Dropping Bottles. 99 Ravenel Culture Dish Holder 181 Ravenel Potato Cutter 414 Raw Materials 524-526 Rawhide Mallet 335 Razors. Section 355 Razor Strops 355 Reaction Plate 408 Reader for Burette Meniscus. 113 Reading Devices for Ther- mometers 126, 284. 500 Reading Glasses 61. 335 Reading Glass for Balances. . 61 Reading Lenses for Colony Counting 168. 169 Reading Lens, Thermometer. 126. 500 Reagents for Abderhalden's Dialyzlng Method 82 Reagents for Rlowpipiner. ... 94 Reagents for Kuttner Micro- Colorimeter 156, 167 Page Reagent Bottles 101-103 Reagent Bottle Caps 102 Recalescence Point Apparatus 263, 271, 417-422 Receivers for Air Pumps.... 79, 80, 90, 92. 414 Receivers, Bell Glass 79. 80 Receivers and Covers for Sieves 441. 442 Receiver for Distillation in Vacuum 426 Receiver, Paulv's 426 Receivers for Pressure Blow- ers 90, 92. 414 Receivers for Retorts 426 Receptacles for Electrical Connections 228 Reckoner, Nomon 373 Record Charts for Milk 358 Recorder for Sunshine 476 Recorders, Temperature .... 419. 498. 499 Recording Barometer 65 Recording Drum 329 Recording Pyrometers 419 Recording Thermometers. 498. 499 Rectifiers, Electric 219 Red Fiber Blocks 354 Red Rubber Tubing 430. 431 Reducer, Brass 506 Reducing Gages 274, 275 Reducing Gear 216 Reduction Factors for Gas. . . 284 Reduction Tubes 427 Reductors. Blair's 427 Reed's Extraction Apparatus. 231 Referees' Gas Apparatus. .11. 282 Reflecting Level. Hand 482 Reflux Condensers 165 Refractory Cement. Alundum 130 Registering Hygrometer .... 317 Registering Thermometers... 495. 497-499 Regulators, Electric 318, 320. 500-502 Regulator. Gas for Auto- claves 28 Regulators, Gas Pressure.... 294 Regulators, Gas Tank.... 274. 275 Regulator. Gas Time 294 Ree-ulators. Pressure for Gas Cylinders 274. 275 Regulators. Temperature, Electric 318, 320, 500. 501 Regulators, Tolul 501 Reichert Gas Regulators 501 Reichert Thermo-Regula tors. 501 Reimann's Thermometer Bodv 51 Relay. DeKhotinsky Iron Clad 500 Renal Functional Apparatus. 156 Rennet Tester. Marschall . . . . 362 Repairs for Galvanometers. . 207 Repairs for Milk Testers 361 Reservoir for Pressure Ttlow- er 90. 92. 414 Resistances. Cenco 224 Resistances, Dodge 226 Resistances. Non-Inductive . . 227 Resistances. Standard 223 Resistance Poxes 220-222 Resistance Bridges 222, 223, 403, 455 Resistance Coils 223 Resistance of Metals Table.. 528 Resistance Spools 223 Resistance Wire 522 Resistance of Wire Table. . . . 527 Respirators 427 Rests for Balances 61 Rests for Bottles 107 Rests for Pipettes 406 Retention Cur,. Water 460 Retorts, All Kinds 25. 174. 198. 199. 427. 428 Retort for Creosote Oil Distil- lation 25 Retorts. Glpss 427 Retorts, Kkidmore's 174 Retorts. Transparent Quartz. 428 Retort Adapters 9 Retort Clamps 146 "Retort Connectors 9 Retort Receivers 426 Retort Rings 428 Retort Stands 477 Retort Supports 477 Revolution Counters 135, 138. 141, 462. 474 Revolving Nosepleces 348 Page Rheostats ..214, 224-226, 260. 263, 266. 346 Rheostats, Battery 214 Rheostats for Electric Fur- naces 260. 263. 266 Rheostats for Micro Arc Lamps 346 Ribbed Funnels 257 Ribbon, Galvanometer Sus- pension 207 Ribbon Carrier for Micro- tomes 353 Richards Filter Pumps 242 Richmond Slide Rule 363 Rickard's Sputum Shaker.... 439 Riders for Balances 56 Rider Weights 51. 56 Riffle Samplers 432. 433 Right Angle Clamps 148-150 Riker Botanical Mounts 95 Riker Plant Press 96 Rlker Specimen Mounts 461 Rings, Concentric 428 Rings, Copper 428 Rings, Filter 19 Rings, Iron 428 Rings for Micro Slides 34fl Rings, Porcelain 428 Rings, Retort 428 Rings. Suberlte 168 Rings for Supports 428 Ring Burners 20, 118 Ring Supports 477 Rip Saw 434 Ripper's Weighing Burette.. 112 Road Material Testers 18-25 Roasting Dishes 188 Rock Crushers 175 Rock Crystal Apparatus ..162, 163. 173, 187, 249. 428. 488 Rock Grinders. . .176, 177, 179-181 Rod, Carbon 524 Rod, Charging for Electro- scopes 424 Rod, Fiber 525 Rods, Gage for Oil 377 Rod, Glass 29fi Rod, Metal, All Kinds 524-526 Rod, Rubber 626 Rods, Silica 443 Rods, Stirring of Glass.. 296, 470 Rods. Stirring, Nafls' 357. 363 Rod Clamp 403 Rod Table, Weight of 528 Roehrig Extraction Tube. 233. 358 Roger's Ring Burner 118 Roger's Sphygmomanometer.. 87 Rolling Mills 180. 181 Rope, Manila 428 Rorrison Oil Thief 379 Rose Crucibles 173 Rose Top (Crown) for Bun- sen Burner 123 Rosettes 228 Ro-Tap Sieve Shaker 443 Rotarex, Dulln 19 Rotary Air Pumps 89-91 Rotary Compressors 89-91 Rotary Converters 226 Rotary Microtomes. Spencer's . .. .' 352. 353 Rotating Anode and Stirring Apparatus 229 Rotators, Electric 229, 470 Rothe Double Automatic Pip- ette 404 Round Levels 333. 334 Roux Culture Tube 48S Roux Gas Regulator 501 Roux Thermo-Regulator. Bi- metallic 501 R. R. Alundum 162 Rubber Bags 279. 282. 428 Rubber Balloons 63 Rubber Bands 428 Rubber Battery Syringe.. 71. 313 Rubber Block for Platinum Combustion Boats 40S Rubber Bottles 103 Rubber Bottle Rests 107 Rubber Bulbs 88, 279, 428 Rubber Bulbs for Constant Blast 88 Rubber Bulbs for Dropping Bottles 428 Rubber Bulbs for Gas Appa- ratus 279. 428 Rubber Bulb Expander 431 Rubber Caps for Test Tubes. 428 Rubber Cloth Aprons 14 CENTRAL SCIENTIFIC CO., CHICAGO, U. S. A. 547 Page Rubber Cloth Balance Covers 61 Rubber Cloth Sleeves 14 Rubber Covered Wire 521 Rubber Crucible Holders 174 Rubber Dam 429 Rubber Disks for Foot Blow- ers 88 Rubber Extraction Appara- tus 231 Rubber Finger Cots 243 Rubber Funnels 258 Rubber Gas Bags 279, 282. 428 Gaskets for Filter 237 Rubber Cones Rubber Gasket for Filter Dish 238 Rubber Gloves 297. 298 Rubber Goggles 298 Rubber Goods 428-431 Rubber Hose 430. 431 Rubber Pestle 451 Rubber Policemen 429 Rubber Rod 526 Rubber Scraper 429 Rubber Sheet 429. 526 Rubber Sheet for Bellows.... 88 Rubber Sheet Covers for Bal- ances -61 Rubber Spatulas 481 Rubber Sprinklers 463 Rubber Stoppers 103, 301. 429 Rubber Stoppers for Moisture Testers 301 Rubber Stoppers for Serum and Vaccine Bottles 103 Rubber Testing Machine 489 Rubber Tips for Glass Rods. 429 Rubber Tissue 429 Rubber Tube Expander 431 Rubber Tubing, All Kinds 430, 431. 526 Rubber Tubing Stretcher.... 431 Ruby Glass Plates 408 Rudolf Coagulometer 83 RuedorfTs Gas Apparatus. . . . 282 Ruhemann's Uricometer .... 509 Ruhmkorff Induction Coils.. 208 Ruhstrat Type Rheostats... Rules, English and Metric... Page Sampler, Milling Machine 160 Sampler and Scoop 432 Sampling Bulbs for Gas Ap- paratus 279. 428 Sampling Cloth 433. 454 Sampling Dishes 433 Sampling Machine 160 Sampling Mailing Cases.. 254. 335 Sampling Pans 302, 433. 461 Sampling Scoops 432. 435 Sampling Shovels 432. 435 Sampling Tray 432 Sampling Tubes. 286, 453, 454. 457 Sampling Tube Brush 453 Sand, Berkshire 620 Sand, Sea 438 Sand, Standard, for Cement Testing 132 Sand Baths 433. 434 Sand Crucibles 173 Sand Glasses 434 Sand Paper 391 Sand Scale 46 Sand Sieves 441 Sand Thermometers 492 Saponification Flask. Volu- metric 250 Sargent Automatic Gas Ca- lorimeter 284 Saucepans 130 Saws, All Kinds. 190. 337, 412. 434 Saw, Automatic Hack 337 Saw, Bone 190 Saw, Circular 412 Saw, Crosscut 434 Saws, Hack 337 434 Saw, Rip 434 Saybolt Universal Viscosime- ter 380 Scales, All Kinds 436 Scale, Bakers' 64. 252 Scale, Cement 46 Scale of Hardness 94 Scales, Measuring, for Hard- ness Tester 304 I Scales. Percentage. . .41, 42, 46. 49 09. Scale, Planner's 94 Scale, Seed or Grain 300 Rules, Parallel 202 Rule, Richmond Slide 363 Rules, Slide 363, 432. 444 Ruled Counting Plates. . .168. 169 Rupert's Drops 432 Saecharimeters, Polariscopes. 412 Saccharometers 315. 509 Saccharometer, Balling's .... 316 Saccharometers, Brix 315 Saccharometer, Elnhorn's . . . 509 Saccharometers, Fermentation 509 Saccharometers, Hydrometers 315 Saccharometer. Lohnstein's. . 509 Saccharometrie Flasks. . .250. 475 Safety Burners, Koch 114. 115 Safety La'mp. Davy's 332 Safety Matches 335 Safety Pipettes 405 Safety Tubes 259 Sahli Haemometer 85 Salinometers 313. 314 Salleron's 'Distilling Appara- tus 199 Salleron's Ebulliometer 204 Salometers 313, 314 Salt Hydrometers 314 Salt Mouthed Bottles 97. 98, 101. 102 Salt Tester for Butter 363 Sample Bottles. .100. 103, 105. 106 Sample Bottles for Oil 100 Sample Bottles for Water... 106 Sample Boxes 20 Sample Cans for Cement 108 Sample Carrying Outfit 454 Sample Grinders. Braun 176 VlV 43S i Scale, Slide, for Milk.363, 432, 444 * 7"*T Sj, .-lie. T^vlnnmil*.** -I .. O Si-ale, Triangular 203 Scale, Turbidity 159. 507 Scale Pan Brushes 109 Scalpels 191 Scheibler Desiccators 184 Schellbach Burettes 111. 112 Schellbach Support 477 Schiff's Burette ". . . 372 SchifFs Nitrometer 372 Schonjahn Grain Germinator. 300 Schreiner's Colorimeter 159 Schroedter Alkallmeter 129 Schroedter Carbon Dioxide Apparatus 129 Schultz Wassermann Bath... 519 Schumann Cement Bottle.... 105 Schumann Specific Gravity Bottle 105 Schuster Dropping Bottle.... 99 Schutte Penetrometer 25 Schwartz Calcium Chloride Tubes 124 Scimatco Burner 119 S imatco Optical Pyrometer. 421 Scissors, Dissecting 192 Scissors. Shears 440 Screw Adjustment Support Clamp 151 Screw Compressor Clamps... 148 Screw Drivers 437 Scleroscope 305 Scoops, All Kinds.. 61, 62, 432, 435 Scoops, Agateware 435 Scoops. Aluminum for Bal- ances 61 Scoop, Cope Weighing 62 Scoops with Counterpoise. . . 54, 61, 62. 252 Scoops, German Silver Weigh- ing 62 Scoops, Glass Weighing 62 Sample Jars 105, 327. 328 Scoops. Horn 435 Sample Oil Bottles 100 Scoop, Nickel Weighing 62 Sample Pans 302. 433 Scoops. Weighing 61. 62 Sample Polishing Machines. . j Score Cards 363 .337. 338 Scoriflers 436 435 435 Sample Shovels 432. Samplers 302. 432, 433. Samplers. Bag 302 Scorifler Molds 366 Scorifier Tongs 503 Sampler, Cement 432 Samplers. Grain and Seed.... 302 Scott Glue Tester 298 Scott Oil Tester 380 Scott Viscosimeter 380 Scrapers, Muffle 435 Scrapers, Rubber for Beakers 429 Screws, All Kinds 75. 334. 436 Screws, Binding 75 Screws. Cork 168 Screws, Leveling 334 Screw Calipers 126 Screw Cap Jars 105 328 Screw Capped Bottles .... _ • 103, 105, 328. 357 Screw Compressors for Rub- ber Tubing i4g Screw Dies 436. 437 Screw Die Stocks 436 437 Screw Drivers 437 Screw Eyes ' 437 Screw Hooks ' 438 Screw Pitch Gage Screw Taps 438 Screw Tap Wrench . 438 Sea Sand 438 Sealing Tubing of Glass 297 Sealing Wax Seco Cork Gage .' 168 Section Knives 351 355 Section Lifters 193 Section Razors 355 Sectional Capillarity Tubes.. 458 Sedgwick-Rafter Apparatus . 5">0 Sedgwick-Rafter Funnel 520 Sediment Glasses 487 Sediment Tester for Milk... 363 Sediment Tubes for Centri- fuges.134, 135, 138, 140. 141. 374 Seekers 193 Selenium Cells " 438 Self Registering Measure 125 Separating Device for Grain. 302 Separatory Funnels ..20, 258. 259 Separatory Funnel for Creo- sote 20 Separatory Funnel for Tar. . . 20 Serological Apparatus .... 82-87, 405. 484-486, 488. 617-519 Serological Pipettes 405 Serological Syringes 484-486 Serological Test Tubes 488 Serological Test Tube Sup- „ Ports 480, 481. 517. 519 Serological Water Baths. 517-519 Serraflnes (Artery Forceps).. 189 Serum Bottles 103 Serum Bottle Stoppers 103 Serum Drying Apparatus .... 83 Serum Filters 236-'38 Serum Ovens 83 Sets of Blowpipe Reagents.. 94 Sets of Dissecting Instru- ments 194 Set of Pure Resistances for Electrolytic Work 223 Sets of Tools 503 504 Sextant 433 Shades of Glass. . . .79. 80, 114 145 Shafts, Counter, for Motors '16 Shaking Apparatus • • •• • • -438-440. 442. 443. 454. 455 Shaking Apparatus for Sieves ••• 442. 443 Shaking Funnels 258 259 Shaking Machines . „,_ 438-440, 442, 443, 454. 455 Sharpener for Cork Borers 167 Sharpener for Pencils.... 395 Sharpies Centrifugal Ma- chines 142. 143 Shaver for Bagasse 17.q Shaver for Ice 317 Shears. AH Kinds 193 440 Shears, Cartilage 193 Shears. Paper 440 Shears. Tinners' Snips. 440 Sheet Carbon 594 Sheet Cork leg Sheet Fiber Sheet Metal. All Kinds 524-526 Sheet Metal Table, Weight of 528 Sheet Rubber 88, 429 5'6 Sheet Rubber for Bellows. . 88 Shelves, Digesting. KJeldahl. -•-..... ^fiQ ^**1 Shelf for Pneumatic Troughs 506 Shells. Extraction 232 233 Shell Vials . 103 Shelter, Meterological . 338 Shields for Centrifuge Tubes ,,.•.••••••-•••135, 138. 140. 141. 374 Shields for Combustion Boats 16' Shimer's Platinum Crucible.. 409 Sho-Gro Germination Testers 300 548 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. Shore's Hardness Tester 306 Shore's Pyrometers 422 Shot, Lead 332 Shovel, Cupel 182 Shovels, Sample 432, 435 Show Bottles 104 Shrinkage Apparatus, Soil... 455 Shunts for Demonstration Galvanometers 213 Shunts for Galvanometers... 206 Shuster Dropping Bottles.... 99 Side Neck Flasks 246. 247 Slemen's Ozone Apparatus... 390 Siemen's Ozone Tube 390 Sieves, All Kinds 302, 440-442 Sieve Bolting Cloth 255. 441 Sieve Frames 255. 441 Sieve Shakers 442. 443 Sieve Sifting Machines. . .442. 443 Sifter, Lightning 443 Sifting Pans 441, 442 Sight-Boxes, Photometer 290 Sight Compasses 164, 482 Signal Marker 501 Silica Beakers 78 Silica Boats 162 Silica Capsules 162 Silica Casseroles 130 Silica Combustion Boats 162 Silica Combustion Tubes 163 Silica Crucibles 174 Silica Dishes 186. 188 Silica Distilling Flasks 246 Silica Evaporating Dishes... 186 Silica Flasks 246, 247. 249 Silica Muffles 367 Silica Rods 443 Silica Test Tubes 488 Silica Triangles 505 Silica Tubes 163 Silica Tubing 443 Silk. Oiled 443 Silk Bolting Cloth 255. 441 Silk Fish Line 165 Silk Peptone 82 Silk Thread 501 Silver Crucibles 174 Silver Dishes 188 Silver Foil 94 Simpler Ore Crushers 176 Simplified Rotary Microtome. Spencer's 352 Single Wall Incubators, De Khotinsky 319 Siphons 443 Siphon Gages 272 Siphon Slide, Holman's 349 Siphon Tubes for Extraction Work 230-232 Six's Maximum and Minimum Thermometer 495 Skidmore's Crucibles 174 Skidmore's Retorts 174 Skim Milk Bottles 367 Skins, Chamois 144 Skin, Goldbeaters' 298 Sleeves 14 Slick. Flour 252 Slides, Culture 349 Slides, Current 349 Slides, Microscopical 348, 349 Slides, Object 348.349 Slide Boxes for Micro Slides. 349 Slide Box for Tar Testing... 26 Slide Cabinet 349 Slide Carriers for Staining Apparatus 464 Slide Cover Glasses 350 Slide Forceps 256 Slide Holders '.. 350 Slide Labels 330. 350 Slide Mailing Cases 350 Slide Mounting Cells 349 Slide Rules 363. 444 Slide Rules, Richmond's 363 Slide Scale for Milk 363 Slide Trays 350 Slide Wire Bridge 403 Sliding Resistances 224, 225 Sling Hygrometers 317 Sling Psychrometers 317 Smith Ductility Machines 21 Smith Fermentation Tubes.. 234 Smith and Hale lonization Cell 399 Smith's Platinum Crucible.. 409 Smoking Pipes 404 Snap Switches 229 Snips 440 Soap, Green Oil 444 Soap, Palm Oil 354 Sockets for Electrical Con- nections 228 Sodium Monochromatic Burn- er 366 Sodium Spoons 462 Soil Acidity Tester, Truog. . . 456 Soil Analysis Apparatus 236, 237, 247, 249. 445-460 Soil Analysis Flasks. 247, 249, 449 Soil Analysis Sieves 441 Soil Augers 452, 463 Soil Balances 43,51 Soil Borers 462. 453 Soil Centrifuges 446. 447 Soil Filters 236. 237 Soil Flasks 247. 249. 449 Soil Grinders and Mills. . .177-181 Soil Pans 445 Soil Sieves 440-442 Soil Thermometers 499 Soil Tubes 457-459 Soil Tube Auger 460 Soil Tube Brushes. . .109, 453. 469 Soil Tube Hoist 454 Soil Tube Rack 460 Solder 460 Soldering Coppers 46C Soldering Irons 460 Soldering Iron Heaters 118 Soldering Outfits 460 Soldering Paste 460 Solidimeter 315 Solution Heaters, Electric... 306. 307 Solution Scales 42, 43, 51. 54 Sommer's Hydrometers for Asphalt 23 Soundness Test Apparatus for Cement 133 Soxhlet Condenser 165 Soxhlet Extraction Appara- tus 231. 232 Soxhlet Extraction Tubes... 231 Soxhlet Flasks 231, 247 Spark Coils 208 Spark Metal Renewal 288 Spatulas, All Kinds.. 255, 410. 461 Spatulas, 1'latinum 410 Spatulas, Steel 255. 461 Specie Jars 328 Species Covers, Botanical.... 96 Specific Gravity Apparatus for Cement 133 Specific Gravity Apparatus for Gas, Chancel's 281 Specific Gravity Apparatus, Jackson's 133 Specific Gravity Balances.... 46, 51, 52 Specific Gravity Balances, Jolly Spring 62 Specific Gravity Balance, Tor- sion 46 Specific Gravity Balance, Westphal 51 Specific Gravity Bottles 24, 104, 105 Specific Gravity Bottles, Bar- rett-Hubbard 24. 104 Specific Gravity Hydrometers 311-313. 315 Specific Gravity Pan. A.S.T.M. 25 Specific Gravity Tubes 104, 105, 133. 459 Specific Heat Apparatus for Soils 456 Specific Resistance Table 628 Specimen Bottles 103-105 Specimen Forceps 256 Specimen Jars... 104, 105, 327, 328 Specimen Mills 179 Specimen Mounts, Riker 461 Specimen Tubes 103. 487 Specimen Vials 99, 100. 103 Spectrum Burner 366 Spectrum Charts 145 Spectrum Lamp 366 Speed Counters.. 135, 138, 141. 462 Speed Indicators for Centri- fuges 135, 138, 141 Speed Reducing Gear for Mo- tors 216 Spence's Lactometer (Hy- drometer) 313 Spencer Immersion Flask. . . . 475 Spencer Lamps 345-347 Spencer Microscopes 339-342 Spencer Pipettes 404. 475 Spencer Ribbon Carrier 353 Page Spencer Rotary Microtomes. . 362, 353 Sperm Candles 292 Spherical Condenser 165 Sphygmomanometer, Roger's. 87 Spinthariscope 426 Spiral Anodes 410 Spiral Condensers 165 Spirit Hydrometers 312 Spirit Lamps 120, 121 Spirit Levels 61, 333, 334 Splints 462 Sponges 410.46:: Sponge, Platinum 410 Spoons, All Kinds... 184, 410. 462 Spoons for Blowpiping. 184 Spoons, Combustion 184. 410 Spoons, Deflagration 184, 410 Spoons, Platinum 410 Spoons, Sodium 462 Spreading Boards, Insect.... 326 Sprengel's Specific Gravity Bottle 105 Springs, Watch 512 Spring Back for Microtome Knives 355 Spring Balances 52, 53 Spring Board Compactor.... 448 Spring Clamps » 146. 147 Spring Clips 152 Spring Divider 200 Spring Gages 272. 273 Sprouting Apparatus, Schoen- jahn's 300 Sprouting Cup 300 Sprouting Media 302 Sputum Bottles 141 Sputum Dish 463 Sputum Shaker 439 Sputum Tray 463 Sputum Tubes for Centrifuge 134 Squares 203. 463 Squibb's Automatic Burette.. 112 Squibb's Separatory Funnel.. 259 Squibb's Ureometer 509 Squibb's Urinometers 510 Stages, Warm, for Micro- scopes 350 Stage Cable Wire 522 Stage Micrometers 347 Staining Apparatus, Electric 464 Staining Dishes 188 Staining Jars 328 Staining Racks 350 Staining Tray 188 Stalls, Finger 243 Stamps, Steel 186 Stands, Wood, for Test Tubes 480. 481 Standard Balls for Hardness Testers 304 Standard Bars for Hardness Tester 304 Standard Calorimeter, Parr... 126 Standard Candles 292 Standard Cells 70 Standard Cell, Weston 70 Standard Clamps 150 Standard Color Tubes for Kuttner Calorimeter ....85. 157 Standard Fermentation Tubes 235 Standard Hygrometer 316 Standard Incandescent Lamps 331 Standard Milk and Cream Test Bottles 358 Standard Paper Thickness Gage 392 Standard Photometric Can- dles 292 Standard Pressure Gage 273 Standard Resistances 223 Standard Sand for Cement Testing 132 Standard Sieves 441. 442 Standard Vacuum Gage 273 Standardized Burettes 112 Standard! zed Cylindrical Graduates 183 Standardized Thermometers. . 491-495. 499 Standard! zed Volumetric Flasks 250 Standard! zed Volumetric Pipettes 406 Star Support for Bunsen Burner 123 Steam Funnels 258 Steam Heated Stills 197, 198 Steam Heated Water Baths. . 513. 614 CENTBAL SCIENTIFIC CO., CHICAGO, U. S. A. 549 Page Steam Jet Filter Pump 243 Steam Pressure Sterilizers (Autoclaves) 26-29 Steam Pumps 243 Steam Stills 197. 198 Steam Sterilizers. Arnold.... 469 Steam Water Baths 514 Steaming Apparatus for Ce- ment 133 Steel Analysis Apparatus 153. 154. 159. 160-163 Steel Balls for Hardness Tester 304 Steel Bars for Hardness Tester 304 Steel Clamps 149 Steel Crucible Tongs. 255, 602. 503 Steel Dies 186 Steel Dishes 433. 434 Steel Dissecting Needles 190 Steel Figures 186 Steel Forceps 256 Steel Letters 186 Steel Measures 125. 272-274 Steel Mortars 177. 366 Steel Needles for Dissecting. 190 Steel Pyrometer Tubes 421 Steel Rod, All Kinds 526 Steel Spatulas 255. 461 Steel Stamps 186 Steel Tape Measures 486. 487 Stt-t-1 Test Tube Support 481 Steel Tubing. Flexible 431 Steel Wheel Glass Cutters... 295. 296 Steel Wire 522 Stencils 463 Slender Dishes 188 Step-Up Transformers 227 Sterilizers. All Kinds 465-469 Sterilizers, Arnold, Steam.... 469 Sterilizers, DeKhotinsky Elec- tric 466 Sterilizers, Hot Air 466-468 Sterilizers, Steam 469 Sterilizers, Steam Pressure Autoclaves 26-29 Sterilizer for Syringes, Dis- secting Instruments, etc... 469 Sterilizer Attachment 469 Sterilizer Bottles 455 Sterilizer Boxes for Pipettes 406 Stevenson and Schaub Mulch Cylinder 450 St.-u- Pans 329 Stewart Counting Apparatus. 168 Strwart Cover Glass Forceps 256 Stk-ks, Charcoal 93, 144 Sticks, Meter and Yard 435 Still. Brown Oil 378 Still. Mercury, Hulett 199 Stills, Tar Testing 20, 21 Stills, Water 195-198 Still. Wine 199 Still Heads 199.200 Stillson's Pipe Wrench 523 Stirrers, Glass 296. 470 Stirring Apparatus 229, 470, 517. 518 Stirring Rods of Glass... 296. 470 Stirring Rods, Nafls' 357. 363 Stocks, Screw Die 436. 437 Stoddard's Clamp Holder 148 Stoddard's Funnel Supports.. 479 Stokes Stills 198 Stones. Oil 373 Stone Jars 329 Stone's Tension Clamp 152 Stoneware Gas Generator.... 287 Stoneware Jars 329 Stoneware Mortars 367 Stoneware Pitchers 9 Stoneware Water Bottle 329 Stop-Cocks, All Kinds.282. 470-472 Stop-Cocks for Gas Bag.. 282, 471 Stop-Cock Grease 472 Stoppers, Cork 166. 167 Stoppers, Rubber ...103, 301. 429 Stoppers, Rubber for Serum and Vaccine Bottles 103 Stop-Rite Time Switches. 443. 502 Stop-Watches 473. 474 Storage Batteries 70-73 Storage Batteries. Edison.... 73 Storage Battery Chargers. 71. 313 Storage Battery Hydrometers 71 Storage Battery Jars 70-72 Storage Battery Testers. . .71, 313 Storage Tank 329 Stoves, Alcohol 120. 121 Page Stoves, Electric 306. 308-310 Stoves, Electric Heating, for Incubators 322 Stoves, Gas 116-118. 310 Stoves, Gasoline 121. 122 Stoves, Kerosene 122 Stoves, Liquid Fuel 120-122 Straight Edge 474 Straus Lactic Acid Funnel... -5.' Straus Separatory Funnel... 259 Streak Plate 16. 94 Stretcher for Rubber Tubing. 431 Strip, Brass 524 Strops, Microtome Knife 355 Student Microtome . — 351 Students' Mineral Collection. 365 Suberite Mats 168 Suberite Kings 168 Sub-Q Safety Syringes 485 Substage Condenser, Abbe... 343 Sucrose Pipettes 405. 475 Suction Filters 242. 243 Suction Pumps 89-92, 242, 243, 414-416 Sugar Analysis Apparatus... 62, 179. 181. 188, 409. 475 Sugar Analysis Dishes, Fused Silica 188 Sugar Analysis Funnel 257 Sugar Analysis Platinum Dishes 409 Sugar Beet Press 414 Sugar Beet Shredding Mill.. 181 Sugar Cane Mills 179. 181 Sugar Capsules 188 Sugar Dishes, Fused Silica.. 188 Sugar Dishes, Platinum 409 Sugar Dish for Weighing... 62 Sugar Flasks 250 Sugar Hydrometers 315 Sugar Pipettes 404. 476 Sugar Presses 181. 414 Sugar Thermometer 496 Sugar Tube, Hortvet's 476 Sugar Weights 57 Sulphonation Test Funnel... 259 Sulphur Apparatus 126, 171, 249, 302, 475. 476 Sulphur and Ammonia Deter- mination Apparatus for Gas Analysis 11,281,282 Sulphur Bulb Tubes 476 Sulphur Crucible 171 Sulphur Determination Appa- ratus.126, 171, 249. 302, 475, 476 Sulphur Dioxide Gas 275 Sulphur Flasks 249 Sulphur in Grain Apparatus. . 249, 302. 476 Sulphur in Oil Apparatus... 476 Sulphur Photometer. Parr... 126 Sulphur Rack 476 Sulphur Turbidimeters ..126. 507 Sulphurated Hydrogen Gas Generators 287 Sulphuric Acid Drying Tube, Vanier 161. 204 Sulphurous Acid Condensers. 165 Sulphurous Acid Gas 275 Sunshine Recorder 476 Supply Tank for Soils 460 Supports, All Kinds 61, 62, 123, 154, 159. 168, 185, 229, 233-235, 343, 397, 398, 406, 458. 477-481. 506 Supports, Adjustable 477-480 Support, Beehive 506 Supports, Burette 478 Supports, Burner 123 Support for Capillarity Tubes 458 Supports for Carbon Tubes. . 159 Supports for Condensers. 477. 478 Supports for Conductivity Cells 397. 398 Supports for Desiccators 185 Supports, Electrolytic 229 Supports for Fermentation Tubes 235 Support for Flasks 168 Supports for Funnels. .. .478. 479 Supports, Glass, for Balance Leveling Screws 61 Support with Heaters for Ex- traction Apparatus ....233, 234 Supports for Microscopes.... 343 Supports for Nessler Tubes.. 154 Supports for Pipettes 406 Supports with Rings 477 Supports for Test Tubes. 480. 481 Support for Weighing Bottles 62 Page Support Levels 833. 334 Support Rings 428 Support Tables 123, 479, 480 Surface Tension Apparatus.. 401 Surveying Compasses . . . .164. 482 Surveying Instruments ...482-484 Surveyors' Arrows 484 Suspensions for Galvanome- ters 207 Suspension Ribbon for Gal- vanometers 207 Swedish Safety Matches 335 Swift B Drug Mill 180 Swimming Cups 484 Switch. Time " 502 Switches for Electrical Work 228. 229 Switchboard for Motor Gen- erator 218 Switchboards for Pyrometers 420 Switchboard Ammeters and Voltmeters 210. 212 Swivel Clamps 151 Swivel Clamp Holders 148 Sy's Extraction Apparatus... 231. 247. 370 Sy's Extraction Flask 247 Sy's Fumeless Digestion Ap- paratus 370 Syracuse Water Glasses 512 Syringes, All Kinds 71. 313. 484-486 Syringes, Battery 71. 313 Syringes, Hypodermic ...484-486 Syringe Needles 485. 486 Syrup Hydrometer 315 Syrup Tube 475 T-Clamps 151 T-Squares 203 T-Tubes 506 Table for Animal Operations 13 Table for Embedding 354 Table, Feet per Ib. of Wire.. 527 Table of International Atomic Weights 144 Table of Magnifications 348 Table of Mendelejeffs Period- ic System of the Elements 144 Table for Microtome 353 Tables for Oil, Tycos 378 Table for Parafflne Embed- ding 354 Table. Resistance of Metal... 528 Table, Turn 350 Table, Warming 350. 351 Table, Weight of Rods 528 Table, Weight of Sheet Metal 528 Table, Wire Gage 627 Table Clamp 151 Table Microtomes 351 Table Supports 479. 480 Tablets, Alkaline, Farring- ton's 357 Tablets, Corrosive Sublimate. 363 Tachometer 486 Tacks, Thumb 501 Tagliabue's Melting Point Tester 377 Tagliabue's Oil Freezer 377 Tallquist Haemogloblnometer 85 Tallquist Haemoglobin Scale 86 Tally, Hand Counter 168 Tank for Air 414 Tank, Evaporation 449 Tanks for Gases 274 Tank, Supply, for Soils 460 Tanks for Water 329, 449. 456 Tank Outfit for Gasoline 122 Tannin Dish, Silica 188 Taps, Screw 438 Tap Drill Scale 435 Tap Sets, and Screw Dies. . . . 437 Tap Wrenches, Screw 438 Tape, Adhesive. Botanical. 95. 486 Tape, Insulating 229 Tapes, Measuring ..484, 486, 487 Tapes, Surveyors' Chain 484 Tape Measures 486, 487 Tapers, Wax 521 Tapered Connectors for John- son's Tubes 163 Tar Determination Apparatus for Gas 285 Tar Flasks, Lunge 247 Tauber's Drying Apparatus.. 204 Teas Extraction Apparatus.. 232 Teclu Burner 118 550 CENTRAL SCIENTIFIC CO., CHICAGO, TJ. S. A. Page Telescope Clamp 151 Temper Drawing Oven, Elec- tric 390 Temperature Bulb for Folin Apparatus 508 Temperature Indicators (Py- rometers) 417-423 Temperature Recorders 419 Tenaculums 193 Tension Apparatus, Surface.. 401 Tension Clamp 152 Tenth Megohm Boxes 222 Terrapin Separator 259 Test Bottles, Milk and Cream 357. 358 Test Bottle Brushes 109 Test Bottle Rack 362 Test Bottle Tester, Nafls.363. 364 Test Clips 76 Test Glasses 487 Test Meters for Gases 284, 285, 289 Test Paper 390, 391 Test Solutions 508 Test Tubes, All Kinds 364, 487, 488 Test Tubes, Butter Pat Oil . . 364, 488 Test Tubes, Transparent Quartz 488 Test Tube Baskets 480. 481 Test Tube Brushes 110 Test Tube Caps, Rubber 428 Test Tube Clamps 146. 147 Test Tube Cleaners 110 Test Tube Filling Attachment 488 Test Tube Racks. 480, 481. 517. 519 Test Tube Rubber Caps 428 Test Tube Stands.480, 481, 517, 619 Test Tube Sterilizer 469 Test Tube Supports I.. .480, 481, 517, 519 Tester, Air, Wolpert 10 Testers, Cement 131, 133 Testers, Cloth and Paper 489 Testers, Fire and Flash Point 22, 375, 376 Tester, Glue, Scott's 298 Testers, Grain 300 Testers, Hardness 303-306 Testers, Linen 334 Testers, Oil 373-380 Tester for Paper, Mullen's... 391 Testers, Rubber 489 Testers for Test Bottles. Na- ns' 363, 364 Tester for Yarn 489 Testing Apparatus for Blood82-87 Testing Apparatus for Ce- ment 131-133, 135 Testing Apparatus, Electrical 205-229 Testing Apparatus for Glue.. 298 Testing Apparatus for Grain 299-302 Testing Apparatus for Hard- ness 303-305 Testing Apparatus for Milk. . • 356-364 Testing Apparatus for Oil. 373-380 Testing Apparatus for Paper, Yarns, Rubber, Cloth, etc.. 489 Testing Machines for Cement 131. 133 Testing Machines for Oil. 373-380 Testing Machines for Rubber 489 Testing Sieves 302. 440-442 Thelco Low Temperature In- cubators 325 Thermit 490 Thermo-Couples for Brown Pyrometers 420 Thermo-Electrlc Pyrometers. 417-423 Thermographs 498. 499 Thermometers, All Kinds.... 18, 20. 126, 127. 255. 302. 364, 490-499 Thermometers. Alarm 493 Thermometers. Armored .... 492 Thermometers. Asphalt Test- ing 18. 20, 492 Thermometer. Bake Oven. 2",5. 493 Thermometers, Beckmann . . . 493 Thermometers, Calorimeter.. 126. 127, 494 Thermometers for Creosote Oil 18, 20. 492 Thermometers for Cryoscopes 493 Thermometers, Dairy 364 Page Thermometer, Dough Testing 255. 494 Thermometers, Gas Calorime- ter 126, 127, 494 Thermometer for Incubators. 495 Thermometers, Low Tempera- ture 491 Thermometers, Maximum and Minimum 495, 497 Thermometers for Moisture Testers 302 492 Thermometer, Pasteurizing.. 364 Thermometer for Pitch Test- ing 18. 20, 492 Thermometers, Precision. .491-495 Thermometers, Recording . . _„ 498. 499 Thermometers, Soil 499 Thermometer, Titre Test.... 492 Thermometers for Viscosime- _ ters 380. 497 Thermometer Charts ....498 499 Thermometer Clamp 148 Thermometer Plummets .... 51 Thermometer Reading De- vices 126. 284, 500 Thermometer Tubes 492, 493 Thermometer Tubing 297 Thermo-Regulators 500. 601 Thermo-Regulator, Ostwald . 501 Thermos Bottles 510 Thermostat Baths 401-403 Thermostats (Incubators) . . . 318-320, 323-325 Thermostats for Low Tem- peratures 401-403, 516, 618 Thermostats (Thermo-Regu- lators 500. 501 Thickness Gages for Paper Testing 391, 392 Thieves for Oil 379 Thief Glasses 379 Thiele's Melting Point Tube.. 336 Thimbles, Extraction ....232. 233 Thimbles, Filter 232, 233 Thistle Tubes 259 Thoma Haemacytometer .... 84 Thoma Mixing Pipettes 85 Thorp Gage 286 Thread, All Kinds 601 Thread Counters 334 Three-Scale Thermometer ... 499 Thumb Tacks 501 Thurston's Oil Testing Ma- chine 377 Thwing Total Radiation Py- rometers 422, 423 Tiles for Combustion Fur- naces 262 Tilter, Carboy 129 Time Clocks 152 Time Glasses 434 Time Marker, Electric 501 Time Regulator 294 Time Switches, Stop-Rite.443. 502 Timer, Interval 152 Tin Boxes 20. 108 Tin Caps 357 Tin Foil Dishes 187 Tin Frame Sieves 442 Tin Measures 336 Tin Pipe 526 Tin Plate Scoop 436 Tin Sheet 526 Tin Tubing 526 Tincture Bottles 97, 98 Tincture Presses 414 Tinned Iron Test Tube Sup- ports 481 Tinned Iron Wire Gauze 523 Tinners' Shears 440 Tinsel Wire 523 Tint Photometer 165 Tintometer, Hess-Ives 155 Tips for Blowpipes 93. 408 Tips for Burettes 113 Tips, Rubber 429 Tirrlll Burner 118 Tissue, Rubber 429 Titre Test Thermometer 492 Titre Tubes 488 T. K. Dropping Bottles 99 Toluol Regulators. Ostwald.. 601 Tongs, All Kinds. 255, 411, 502, 503 Tongs, Cupel 503 Tongs, Crucible 255, 602, 503 Tongs, Cylinder 255, 503 Tongs, Gas 411 Tongs. Scorifler 503 Tool Cabinets 503. 504 - Tool Holders 503. 504 Tool Sets 503. 504 Tool Steel Mortars 366 Tops for Burners, Gauze.... 123 Tops for Burners, Wing 123 Torches, Gasoline 121 Torches, Laboratory 121 Torsion Balances 41-46 Torsion Balances for Cream Test 41 Torsion Balance, Specific Gravity 4$ Total Carbon Apparatus 126 Towelling, Crash 504 Towers, Calcium Chloride 124 Tracing Cloth 152 Trains, Combustion 160. 161 Tralle Hydrometers 312 Transfer Pipettes 405. 406 Transference Tubes, Wash- burn 403 Transformers for Charging Storage Batteries 217. 218 Transformers, Electric. . .226. 227 Transparent Adhesive Tape.. 95. 48C Transparent Quartz Appara- tus 78, 162, 163, 173, 187, 249, 428. 488 Transparent Quartz Beakers 78 Transparent Quartz Combus- tion Boats 249 Transparent Quartz Combus- tion Tubes 163 Transparent Quartz Crucibles 173 Transparent Quartz Dishes.. 187 Transparent Quartz Flasks.. 249 Transparent Quartz Retorts. 428 Transparent Quartz Test Tubes 488 Transplanting Trowel 506 Traveling Outfits (Milk Test- ers) 360. 361 Tray, Cupel 182 Trays, Filtering 237 Trays, Germinating 299, 300 Trays, Micro Slide 360 Trays, Mineralogical Speci- men 365 Trays, Photo 504 Trays, Sampling 432 Trays, Soil 457 Trays, Staining 188 Triangles, All Kinds 185, 203, 504. 505 Triangles, Drawing 203 Triangles, Glass 185 Triangles, Platinum 411 Triangles, Silica 505 Triangle Holder 505 Triangle Support 185 Triangular Desiccator 185 Triangular Files 235 Triangular Scale 203 Trip Scales 54 Triple Aplanatic Magnifiers. . 335 Triple Wall Incubators. . .318, 323 Tripods 505 Tripod for Bunsen Burner... 123 Tripod for Desiccators 186 Tripod Magnifier 336 Troughs, Pneumatic 506 Trowels, All Kinds 133, 506 Trowels for Cement Testing. 133 Troy Weights 69 Trunnion, Acid Bottle 356 Truog Soil Acidity Tester. . . . 456 Try Squares 463 Tube Gages 272, 273 Tubes, All Kinds 506. 607 Tubes, Absorption 8, 9, 124, 145, 160, 161, 371, 413. 414 Tubes. Air Thermometer .... 10 Tubes, Alundum 261 Tubes, Ammonia Test 11. 153 Tubes, Arsenic 17 Tubes, Barometer 65, 297 Tubes for Blowpiping 94 Tubes, Board of Health 141, 487. 488 Tubes, Boiling Point, for Molecular Weight Determi- nation Apparatus 401. 402 Tubes, B. S. for Oil 140. 374 Tubes, Bulb Connecting for Marshall's Urea in Blood Apparatus '87 Tubes, Butter Fat Oil 364 Tubes, Calcium Chloride 124 Tubes, Capillary 297 CENTRAL SCIENTIFIC CO., CHICAGO, U. 8. A. 551 Page Tubes, Capillary Electrome- ter 398. 399 Tubes, Capillarity 457. 458 Tubes, Carbon Filter 257 Tubes, Carius Bomb 297 Tubes, Casein 138. 141. 358 Tubes, Centrifuge 134, 135, 138, 140, 141 Tubes, Chloride of Calcium.. 124 Tube, Chlorine 145 Tube. Chlorine Absorption... 145 Tubes. Color 153. 154 Tubes, Combustion 163. 297 Tubes. Combustion. Platinum '408 Tubes, Comparison 153 Tubes, Condenser 165 Tubes, Connecting, for Gas.. 506 Tubes. Connecting, for Mar- shall's Urea in Blood Appa- ratus 87 Tubes, Cream 364. 488 Tubes, Culture ..487. 488 Tube, Dissolving 195 Tubes; Distilling 199. 200 Tubes, Drying 124. 204 Tubes, Eggertz 153 Tubes. Extraction 230-233 Tubes, Fat Extraction. Roeh- rig 233 Tubes, Fermentation ....234, 235 Tubes. Filter 257 Tubes, Folin for Marshall's Urea In Blood Apparatus. . 87 Tubes, Fractionating^. .. .199, 200 Tube. Freas Dissolving 195 Tubes, Freezing, for Molecu- lar Weight Determination Apparatus 400 Tubes, Funnel 257. 259 Tubes, Gas Collecting 286 Tube, Gas Filter 287 Tubes. Glass, Annealed Ends 296. 297 Tubes, Glass, for Blowpiping 94 Tubes. Goetz Phosphorus. 135, 141 Tubes, Gooch Filter 257 Tubes for Haematokrlt 134 Tubes. Hard Glass 94, 427. 488 Tube, Hortvet's 476 Tubes, Ignition 427, 488 Tubes. Liebig Drying 204 Tubes for Mailing 254. 335 Tubes, Manometer 273 Tubes. Marchand's Calcium Chloride 124 Tubes, Melting Point, Thiele's 336 Tubes, Migration 399 Tubes, Milk for Centrifuge... 135. 138. 141 Tubes. Nessler 153 Tubes. Oil 140. 374 Tube. Ozone. Siemen's 390 Tubes. Palladium for Gas Analysis 290 Tubes, Pelligot's Calcium Chloride 124 Tubes, Percentage, for Haem- atokrit 134 Tubes. Percolation of Air.... 459 Tubes, Phosphorus. Blair's.. 427 Tube, Platinum 408 Tubes. Porcelain 163 Tubes. Pyrometer 420. 421 Tubes, Quartz 163 Tubes. Reduction 427 Tubes, Roehrig Extraction.. 233 Tubes. Safety 259 Tubes, Sample 103. 105. 286 Tubes. Schwartz Calcium Chloride 124 Tubes, Sealing 297 Tubes. Sediment for Centri- fuges 134. 135, 140. 141. 374 Tubes. Silica 17. 163 Tubes. Siphon, for Extraction Work 230-232 Tubes, Soil 457-459 Tubes. Soxhlet 231 Tubes, Specific Gravity . .104. 105 Tubes. Specimen. 103, 105. 487. 488 Tubes, Sputum for Centrifuge 134 Tubes, Sugar 475 Tubes, Sulphur 476 Tubes, Syrup 475 Tubes. T 506 Tubes, Test 487. 488 Tubes, Thermometer ....492. 493 Tubes, Thistle 259 Tubes, Transference, Wash- burn 403 Page Tubes, U 124. 506 Tubes, Urine 134, 135 Tubes, Vaccine 138. 141 Tubes. Vacuum BIO Tubes, Viscosity 403 Tube, Volume Weight 459 Tubes, Water Analysis 153, 164. 620 Tubes. Water Holding Capac- ity 459 Tubes, Weighing 106. 107 Tubes. Y 506 Tube Balance, Centrifuge... 14! Tube Brushes 108-110. 459 Tube Brush for Burettes.... 108 Tube Brushes (Test Tube) . . 109 Tube Clamps 146-148 Tube Furnace. Carius 2 Tube Furnace, DeKhotinsky.. 2 Tube Furnace. Hoskins 260 Tube Furnaces. Multiple Unit 2«1 Tube Gages 125. 272. 273 Tube Support Stands 154, 159. 480. 481, 517, 519 Tuberculin Syringes, Luer.. 484. 486 Tubing, Barometer 65. 297 Tubing. Brass', for Burner... 117 Tubing. Burner 117. 430, 431 Tubing. Combustion 163. 297 Tubing. Fiber 526 Tubing. Flexible Metallic.117. 431 Tubing, Glass 296. 2! Tubing, Lead 626 Tubing. Metallic. All Kinds. ......... . 524-52 Tubing. Rubber 430. 431 Tubing, Silica 163. 443 Tubing. Thermometer 2 Tubing. Transparent Quartz. 163 Tubing Connections 506 Tubing Gages 272. 2 Tubing Gage. Micrometer . . . 126 Tubing Stretcher 431 Tuerk Counting Chamber.... Tumblers. Glass 329. 458. S07 Tungar Rectifiers 2 Turmeric Paner S Tungsten Filament I>amps. .. 3: Turbidimeters 1R9. 507 Turbidimetpr. Sulphur ...12fi. 507 Turbidity Scale 169. 507 Turbine. High Speed 470 Tiirk Haemacvtometer 84 Turkev Red Cloth.... 1 Turned Wood Boxes 1 Turn-Table 350 Tutweiler Modification of Hemnel Gas Burette ? Twaddle Hydrometers S Tweezers -• , - 256 Twine 17. 165. 507 Twist Drills 204 Twisted F1<»T Co'd 165 Two-Wav Stop-Cocks ...471. 472 Tycos OH Tables 378 I' Tubes 124. R06 T-bhelnhde Viscosimeter 379 T'. G. T. Gas Apparatus 2 U. G. I. Gas Ptoette 294 T*. G. I. Heat Value Computer 2R4 Ukena's Color Comparator. .. 1 Umpire Ore Samplers 433 Underwriters' laboratories Extraction Apparatus 232 U. S. Bureau of Mines Flash Point Testers 376 U. S. Bureau of Mines Gas Analvsls Apparatus ...276. 277 tT. S. Bureau of Mines Gas Collecting Tubes 286 V. .S. Bureau of Mines Gaso- line Distillation Apparatus. 374 T" S. Bureau of Mines Oil Testers 374. 376 V. S. Customs House Alcohol Hvdrometer 312 P. P. Department of Agricul- ture Hvdrometers 313 U. S. Geological Survey Colo- rimeter 159 U. S- Geogolical Survey Tur- btdiTtieter 159. 507 t" S. P. Green Oil Soap 444 t". S. Signal Service Barome- ter 64 U. S. Steel Gas Apparatus... 280 Page Universal Clamps and Clamp Holders 148 Jnlversal Compound Rotator 2 Jnlversal Hose Connectors.. 308 Universal Hydrometer 3 Jniversal Meteorological Set 338 Universal Motor 214 Universal Sampler. Braun's.. 433 Jnlversal Shunts for Galvan- ometer 206 Universal Viscosimeter, Sey- bolt 380 Universal Wax 521 Ure Eudiometers 23