ASSOCIATIONS FOR THE ADVANCEMENT OP SCIENCE. 



35 



were discussed ; also the extinguishing powders 

 were mentioned. Under the methods of protec- 

 tion against fire, he described processes of ren- 

 dering structural materials fireproof; then the 

 textiles and papers were taken up, including 

 theater curtains, scenery, ropes, ball dresses; also 

 various forms of fireproof paper and ink were 

 described. He concluded that for textile fabrics 

 sodium tungstate and magnesium borate yield 

 the best results when materials are to be ironed, 

 while ammonium phosphate or sulphate are pref- 

 erably used in other cases. In the way of op- 

 portunities for future investigation, the further 

 study of illuminarits was advised. Whatever 

 tends to replace the use of petroleum for domestic 

 lighting tends by so mjjch to diminish the na- 

 tional fire bill, as this one substance is the most 

 prolific cause of conflagration. The use of vege- 

 table oils or the introduction of a fuel gas so 

 safe and economical that it may be promptly 

 accepted for domestic lighting was advised. The 

 substitution of aluminum for wood as a struc- 

 tural material was referred to as probable, and as 

 affording a solution of the problem in that direc- 

 tion. As to the production of new protectives, 

 there is but little doubt that other combinations 

 less expensive or more effective than those now 

 in vogue await the experimenter. By impreg- 

 nation it was doubtful if anything better than 

 ammonium phosphate could be obtained, but 

 its economical production could be profitably 

 studied. 



The following-named papers were then read 

 and discussed before the section : 



" Observations regarding Certain European Water 

 Supplies," by William P. Mason ; " Fallacies of Post- 

 mortem Tests for Morphine," by David L. Davoll: 

 "Camphoric Acid," by William A. Noyes; "Double 

 Halides of Antimony and Potassium," by Charles H. 

 Herty ; "Some Peculiar Forms of Iron," "On the 

 Existence of Ortho-silicic Acid," and " Volatility of 

 Certain Salts," by Thomas H. Norton; "A New 

 Formula for Specific and Molecular Eefraction," by 

 W. F. Edwards; "Action of Nitric Acid upon the 

 Chlorides of Zinc, Bismuth, and Cadmium," by Otis 

 C. Johnson ; " A Convenient Milk-sampling Tube," 

 by M. A. Scovell ; " The Polymetric Modifications of 

 Propionic Aldehyde, Parapropionic Aldehyde, and 

 Metapropionic Aldehyde," by William E. Orndorif ; 

 " A New Gas and Oil Field," by E. H. S. Bailey ; 

 " On the Behavior of Allyl-malonic, Allyl-acetic, and 

 ^thylidene-propionic Acids when boiled with Caus- 

 tic Soda Solution " and " On the Grade of Ethernar- 

 cosis in Eelation to the Amount of Inhaled Ether 

 Vapor," by John G. Spenzer; and "The Test of 

 Fluorin for the Determination of the Antiquity of 

 Fossil Bones," by Thomas Wilson. 



D. Mechanical Science and Engineering. 

 The presiding officer of this section was Mansfield 

 Merriman, who fills the chair of Engineering at 

 Lehigh University, South Bethlehem, Pa. His 

 address was on " Paradoxes in the Resistance of 

 Materials." It discussed the importance of tak- 

 ing into account the effects of falling bodies, 

 phenomena liable to occur in machinery, on 

 bridges, arid even in buildings, and a full ac- 

 count was given of the history of the development 

 of our knowledge on the subject. Beginning in 

 1807 with Young, who first recognized that im- 

 pact was a case of energy or work, which he called 

 resilience, the labors of Navier, Poucelet, Hodg- 

 kinson and many others were described at length. 

 The subject was' divided into two parts, "elastic 



resilience" and "ultimate resilience," the former 

 being the case where the elastic limit of the ma- 

 terial is not exceeded, and the latter where rup- 

 ture occurs. The. conclusions of elastic resist- 

 ance under impact are derived mainly by theory, 

 and teach that a sudden force produces 'twice as 

 much elongation and twice as much stress as a 

 force slowly applied. The conclusions of ulti- 

 mate resistance under impact are derived by 

 tests made with a falling ram, and these in gen- 

 eral give different laws from those of the case of 

 pure elasticity. The development of the modern 

 methods of static testing in the United States be- 

 gun by Wade, Rodman, and Plympton, the later 

 testing machines of Fairbanks, Olsen, Riehle, 

 and Thurston, the culmination in the precise ap- 

 paratus of Emery, and the powerful machine at 

 Phoanixville were described. The results obtained 

 from these tests, it was thought, did not give as 

 full information- regarding resilience as is desir- 

 able. The cold-bend test was characterized as 

 of great value, and one that no engineer would 

 desire to see abandoned. A number of para- 

 doxes or misunderstandings regarding the pres- 

 sure caused by impact and the relation between 

 stress and work were reviewed, and most of these 

 were shown to have had their origin in a lack of 

 clear conception and correct application of the 

 principles of mechanics. In view of the lack of 

 precision which is frequently apparent, it was 

 urged that greater attention should be given in 

 technical schools to experiments and numerical 

 computations of physical phenomena. The dis- 

 cussions of Herbert Spencer regarding laws of 

 persistence of force and of continuity of motion 

 were characterized as inexact, and it was claimed 

 that the law of conservation of energy should be 

 made the basis of all dynamical investigation. 



The following-named papers were read and 

 discussed before the section : 



" The Crank Curve," by John H. Kinealy ; " Pre- 

 liminary Experiments on a New Air Pyrometer for 

 measuring Temperatures as High as the Melting 

 Point of Steel, " On the Precautions necessary in the 

 Use of Mercurial Thermometers in determining the 

 Amount of Super-heat in Steam," and " Improve- 

 ments in Methods of testing Automatic Fire-sprink- 

 ler Heads," by David S. Jacobus; " On the Katio of 

 the Expansion of Steam in Multiple Expansion Marine 

 Engines for Maximum Economy in Fast Eiver Steam- 

 ers," by James E. Denton ; " Experiments on the 

 Transverse Strength of Long-leaf Yellow Pine," by 

 Samuel Marsden ; " The Air Lift Pump," by Elmo 

 G. Harris ; and " Some Eeminiscences of the 'History 

 of Iron Bridge Building in the United States," by 

 George W. Plympton. 



E. Geology and Geography. This section was 

 presided over by Samuel Calvin, who fills the 

 chair of Geology in the State University of Iowa. 

 His address was on " Some Points in Geological 

 History illustrated in Northwestern Iowa." He 

 said : " The Niobrara stage of the Upper Cre- 

 taceous is well represented along the Missouri, 

 from the mouth of the Niobrara river to the 

 mouth of the Big Sioux. East of the Sioux 

 beds of the same stage are found at various 

 points in Iowa as far eastward as Auburn, in Sac 

 County, while fossils distributed through the 

 drift indicate the former existence of Cretaceous 

 strata at points many miles farther east than 

 any locality where they are not known to occur 

 in 'place. The general distribution of the Nio- 



