INDUSTRIAL A N D ENGINEERING CHEMISTRY
528
(111) Periodicals abstracting chemical patents (selected list) : 1-Chemical Abstracts, 1907 to date (numerical indexes 1912-14 only). 2-Journal of the Society of Chemical Industry, 1882 to date (numerical indexes of British patents since 1901, and of others since 1916). 3-Chemisches Zentralblatl (has numerical indexes of German patents; five-year collective indexes from 1897 on). 4-Chemisches Reperlorium (abstract section of Chemiker-Zeitung until replaced by Chemisch-technischc Ubersicht) gave fairly complete number list of patents for all the principal nations. 5-Zeitschrift fur angewandte Chemie (1888 t o date) (has annual numerical indexes of German patents). 0-Wagner’s Jahresbericht ilber die Leistungen den chemischen Technologic (numerical indexes of German patents annually from 1888). 7-L’industrie chimipue (1914 to date), French patents chiefly. 8-Reuue des produils chimiques (1898 to date). 9-Journal of the Society of Dyers and Colorists. 10-Monthly Abstvacl Bulletin (Eastman Kodak Company). 11-Journal of the Chemical Society (numerical indexes of patents of principal nations annually from 1913; but not many patents are abstracted). 12-Dingler’s Polytechnisches Journal.
(IV) Handbooks, etc. (selected list) : 1-Macomber, “Engineer’s Handbook of Patents.” 2-Thomas, “Chemical Patents” (1916). 3-Fairweather, “Foreign and Colonial Patent Laws” (1910). 4-Walker, “Patent Laws of the United States.” 5-Ephraim, “Deutsches Patentrecht fur Chemiker” (1907). 6-“Rules of Practice” (U. S. Patent Office). 7-Lg.nch, “Canadian Patent Office Practice” (1909). &“Manual of Classification” (U. S. Patent Office). 9-“Manual of Classification of the German Patent Office.” edition of 1910 (translated into English by Lovett, and issued by the U. S. Patent Office). IO-“Key to the Classification of the Patent Specifications of France, Germany, Austria, Netherlands, Norway, Denmark, Sweden, and Switzerland’’ (third edition, published by the British Patent Office). 1I-“Abridgment Class and Index Key” (British Patent Office). la-Samter, “Physikalische Cbemie und das Patentrecht” (in Vol. 21, 1917, of Ahren’s “Sammlung Chemische technischer Vortragen”). la-Witt, “Chemische Homologie und Isomerie” (discussion as related t o patent laws and practice). 14-Barrows, “Patent Law of Interest to Chemists” (series in course of publication: first paper in INDUSTRIAL A N D ENGINEERING CHEMISTRY, 15, 80 (1923). I5--”Guides to the Patent Office Library” (London). These include AA-BE, Reference works; BF-BL, Patent and Copyright Laws; ZC-ZQ, chemistry. 16-Kraetzger, “Ausftihrungszwang in Patentrecht.”
(V)
IO-John Crerar Library (Chicago). 11-Chicago Public Library. 18-St. Louis Public Library. 13-Mercantile Library (St. Louis). 14-Rose Polytechnic Institute Library (Terre Haute). 15-Grosvenor Library (Buffalo).
Importance of Position in Weather Tests1I2 By Percy H. Walker BUREAU
E
(VI) Periodicals devoted t o patent law, patent office practice, and related subjects: 1-Journal 8-Patent
of the Patent O f i c e Society (Washzngton). and Trade Mark Review ( N e w York).
(VII) Library list (some libraries in the United States having partial or complete files of patent publications) : 1-Scientific Library, U. S. Patent Office (Washington). 2-New York Public Library (New York City). 3-Public Library of the City of Boston. 4-Carnegie Library of Pittsburgh. 5-Library of the Franklin Institute (Philadelphia). 6-New York State Library (Albany). 7-Library of the State Historical Society of Wisconsin (Madison). 8-Columbia University Library (Pu’ew York City). +Yale University Library (New Haven).
O F STANDARDS,
WASHINGTON, D.
c.
XPOSURE tests on paints consume so much time that it
is especially important to consider all factors which tend to increase or decrease the time required. Of all the factors entering in weather tests for paints, sunlight is by far the most important. Test panels should‘therefore be exposed so as to get the maximum sunlight. Several years ago the writer’s laboratory adopted an inclination of 45 degrees facing south as the standard position, and until as late as February, 1924, no objection to this plan was heard. Since some well-known experts now insist that exposure tests be made in a vertical position, it seems advisable to point out the advantages of the inclined position. It is obvious that a fixed plate anywhere in the northern hemisphere will receive the greatest amount of illumination averaged for all hours of the day and all days of the year if placed facing south and a t an angle to the horizontal the same as the latitude of the place of exposure. Paul R. Heyl, of the Bureau of Standards, has kindly furnished average values calculated for all hours of the day and all days of the year of the relative normal intensity a t 45 degrees as compared with the theoretical slope and also the relative normal intensity on a vertical surface compared to the 45-degree surface a t the various selected latitudes, The table gives these values for practically extreme points in the United States.
Dates of first patent grants, and early patent records:
I-GREAT BRITAIN: 1617. “Abridgments and Specifications” with Indexes, 1617 t o date. 2-Ux1TED STATES: 1790. “Patent Office Index,” “Reports,” etc. 1790 to date. Q-FRANCE: 1791. Index, 1791 to date; Abridgments, 1791 to date. I-CANADA: 1824, Abstracts of patents, 1824 t o date. SPAIN IN: 1833. 6-AUSTRIA: 1854. Patenl O.& Index, 1854 to date. ~-BELGIUM: 1854. Recuefl des breuets, 1854 to date. 8-BOLIVIA: 1858. ~-ARGENTINA: 1864. ~C--ITALY: 1864. I l - C o ~ o ~ s r ~ 1869. : 12-PERU: 1869. 13-GERMANY: 1877. 14-RUSSIA: 1896. 15-AUSTRALIA: 1903. 16-JAPAN: 1905. I ~ - H o L L A ~ D : 1912 (repealed act of 1869 prohibiting the grant of patents).
Vol. 16, No. 5
NORTH LATITUDE
RATIOO F NORMAL INTENSITY Ratio Normal Intensity Exposed a t 45’ t o T h a t when Exposed a t Latitude Angle 0.999 0.999 0,998 0.995 0.974 0.961 0.934
Ratio Normal Intensity when Exposed in Vertical Position to T h a t when p p o s e d a t 45 0.74 0.67 0.66 0.64 0.53 0.48 0.41
It will be noted that the relative normal intensity a t the theoretical slope differs from that a t the 45-degree slope by less than 1 per cent for all points in the United States north of Washington and by less than 7 per cent for all points between Key West and Seattle. It will be further noted that in the northern part of the United States the normal intensity on a vertical surface is less than three-fourths, and in the southern part of the United States less than one-half that on a surface a t 45 degrees. It is not easy to make racks a t odd angles such as 41, 39 degrees, etc. Hence in the United States it is advisable to make all weather exposure tests facing south and inclined a t an angle of 45 degrees. Since writing the above the author finds that Pulsifer3 states that a panel exposed a t an angle of 45 degrees facing south will perish in about one-half the time of an exactly similar panel exposed vertically, and a panel exposed vertically facing north will last approximately twice as long as one exposed vertically facing south. Presented before the Section of Paint and 1 Received April 14, 1924. Varnish Chemistry a t the 67th Meeting of the American Chemical Society, Washington, D. C.. April 21 t o 26, 1924. 2 Published by permission of the Director of the Bureau of Standards 0 the U. S. Department of Commerce. 8 Drugs, Oils, and Paints, 39, 356 (1924).
