Master Track Scales. Of the 19 master track scales in operation in various sections of the United States, 15 were tested during the fiscal year, and the remaining 4 were tested shortly after July 1 and will be included in the next yearbook. The condition of the equipment has been found very satisfactory. Thirteen of the scales were found to be accurate within the "maintenance tolerance" of approximately 0.02 per cent of the values of test loads applied. As the two remaining scales had been overhauled or modified before this test, the maintenance tolerance did not apply. The scales were adjusted as necessary and all were left within the "adjustment tolerance," about 0.01 per cent. RUBBER Floor Tile.-Investigations conducted during the year resulted in a comprehensive report on the properties of rubber floor tile. This report has been discussed at various conferences with manufacturers and users of this material, and further work suggested by them is planned. It is desired to obtain and to make available definite information regarding the physical properties desirable in rubber floor tile, and the conditions of service to which this material is best adapted. Sponge Rubber.-A survey of the manufacture of sponge rubber has been made. Samples of sheet sponge of various types have been obtained from several sources and are being studied with reference to the following properties: Hardness, porosity, strength, permanent set, water absorption, buoyancy, hysteresis under compression, cushioning properties, and heat insulation. A report giving the more valuable information now available on this material has been prepared. Deterioration of Rubber.-An oxygen bomb for accelerated aging of rubber compounds in oxygen under pressure has been installed, and data are being obtained to show how this test compares with the aging test now in use, the object being to develop a more dependable means for predicting the life of rubber goods. Abrasion Tests. Based on abrasion tests of various kinds made at the bureau and on the published results of investigations conducted elsewhere, a new abrasion machine for rubber has been designed and built. Data on the performance of this machine are being obtained with a view to establishing a standard abrasion test suitable for use in specifications. Effects of Temperature and Humidity. The research fellowship established by the rubber division of the American Chemical Society has been continued, and the investigation of the effects of humidity and temperature upon the stress-strain relation, and upon the abrasive resistance of rubber have been completed, and reports published. With the intention of establishing a standard procedure, a detailed study of the methods used in the preparation and testing of samples in various rubber laboratories throughout the industry has been begun. Publications. Importance of Temperature and Humidity Control in Rubber Testing, Part I, Stress Strain and Tensile Properties, Rubber Chemistry and Technology, November, 1928; Part II, Abrasive Resistance, Industrial and Engineering Chemistry, Analytical Number, July, 1929. SAFETY CODES A new edition of Handbook No. 4, containing a discussion of the National Electrical Safety Code, has been issued; it is a companion volume to the fourth edition of the code itself (Handbook No. 3). Work has continued upon a pictorial edition of the code. Letter Circular No. 261, showing the extent to which the code is applied by State authorities and bringing up to date information of this character reported in detail in the 1929 Yearbook, has been prepared. Assistance in preparing new electrical rules has been given State commissions in Nevada and Wisconsin. Miscellaneous Publication No. 92, containing a code for protection against lightning, has been issued and used in the preparation, for the National Fire Protection Association, of a report on protection against lightning. A companion volume dealing with the protection of electrical lines and equipment is now in press, and will constitute Miscellaneous Publication No. 95. Data collected by the Western Actuarial Bureau regarding damage to property of electric utility companies have been analyzed by members of the bureau. Work has continued on the revision of the Elevator Safety Code, and a portion of a handbook for elevator inspectors-that dealing with routine reinspections-has been completed. Much work has been done in cooperation (1) with a committee of the American Engineering Council on street-traffic signs, signals and markings, and (2) with a committee of the National Conference on Street and Highway Safety on a model traffic ordinance for cities. Both projects have been completed. The bureau's section of safety standards has taken an active part in the work of committees preparing or revising industrial safety codes. Of these codes the following have been completed: (1) Mechanical refrigeration; (2) textile safety; (3) window washing; (4) floor openings, railings, and toe boards; (5) woodworking safety; and (6) factory lighting. The following codes are still incomplete: (1) Walkway surfaces; (2) conveyors and conveying machinery; (3) cranes, derricks, and hoists; and (4) colors for gas-mask canisters. Members of the section participated actively in the preparation of the 1929 edition of the National Electrical (Underwriters) Code. A 1929 edition of a combined electrical code, covering both accidentprevention and fire-prevention rules, has also been drafted. A report on dry-cleaning and dyeing establishments has been prepared for the National Safety Council. The Safe Practices Pamphlets of the National Safety Council were reviewed before promulgation. The bureau has severed its connection with the Safety Code for Aeronautics. PuNications—Discussion of the National Electrical Safety Code, B. S. Handbook No & 1928 Code for Protection Against Lightning, B. S. Mise. Pub. No. 92, 1929. SIMPLIFIED PRACTICE Recommendations Completed. In the 1929 edition of this yearbook, those simplified practice recommendations were listed as completed, which had been considered by a general conference. In this edition only those recommendations which have been sccepted by organizations representing 80 per cent of the total volume of prodier of the industry are sted as completed. Because of this change in classification, certain recommendations included in the 95 sted last year as completed prior to July 1, 1928, are repeated in this year's total of 98. The latter figure includes all recommendations on which a satisfactory volume of acceptance was received prior to July 1, 1929. Twelve new simplified practice recommendations were completed last year. They are as follows: New simplified-practice recommendations completed during the fiscal year ended June 30, 1929 1 General conference held prior to July 1, 1928, therefore listed in previous yearbook as completed. ? Establishes clearance dimensions and terminology for skid platforms. Establishes 5 standard weights with maximum dimensions. • Figures not available. Approximate. Recommendations in Process of Acceptance. Thirteen simplifiedpractice recommendations and one regional recommendation are in process of acceptance. 1 Establishes basic and uniform standards for pyroxylin-coated fabrics. Figures for, not yet available. Screen sizes and terminology. 168 22 87 2220 8 8 60 93 Regional Recommendations. Recently the division of simplified practice has been developing a new service to industry in the form of regional recommendations. Hitherto the work has been confined to projects which from their inception were national in scope. It has, however, become increasingly evident that the division has a large field of service in assisting to develop programs covering only a part of the United States. Obviously some limit must be set up beyond which the division can not be expected to go, and for the present it has been decided to limit this new activity to (a) natural products or commodities, and (b) to programs which hold forth a definite promise of ultimately developing into national recommendations. Progress. A comparison of the progress for the past year with that of the previous year shows an increase of 24 per cent in the number of simplified-practice recommendations adopted by general conferences. It is also interesting to note that the number of individual accepters increased 113 per cent during the past year. Progress for the fiscal year ended June 30, 1929 Adherence to Recommendations. Regular periodic surveys of the various industries that have adopted simplified-practice recommendations are made to determine the degree of adherence these industries are giving to the recommendations. The results of these surveys, as shown in the table below, indicate that during the fiscal year 1929, 86 per cent of the total output of the accepters was made in accordance with the simplified schedules. Revisions and reaffirmations for the fiscal year July 1, 1928, to June 30, 1929, supported by survey Revisions and reaffirmations for the fiscal year July 1, 1928, to June 30, 1929, supported by survey--Continued In addition to those shown above, the following simplified practice. recommendations were reviewed during the past fiscal year: Structural slate, roofing slate, blackboard slate, plow bolts, cotton duck, steel lockers, grinding wheels, cut tacks and small cut nails, carbon brushes and brush shunts, rotary cut lumber stock for wirebound boxes, hospital and institutional cotton textiles, binder's board, kalamein doors, and hacksaw blades. A comparison of adherence from year to year is included so as to present an adequate picture of industry's conformity to existing recommendations. Savings. During the past fiscal year an effort was made by the division to evaluate the savings which have accrued to the various industries concerned, due to simplified-practice recommendations now in effect. Data of a tangible nature were impossible to secure. However, estimates of the value of simplified practice by responsible mem |