NA TURE 



[July 22, 1922 



the end of the cut, and the stress distribution becomes 

 much more complicated. 

 The stress in glass tools when cutting nitro-cellulose 

 . itudied, and it is found that when the material 

 is being removed in a thin shaving by a true cutting 

 action the stress system is of a simple radial type. 

 The colour bands are very nearly arcs of circles 

 passing through the cutting edge as indicated in 

 Fig. 3, and are such as would be produced by the 

 action of a concentrated force applied at this place. 

 They arc. in fact, of the same type as those obtained 

 when a non-axial force is applied at the apex of a wedge, 

 giving isoclinic curves and colour bands (Fig. 5), all of 

 which pass through this point up to the yield point 

 of the material. The centres of the circular arcs of 

 these latter bands all lie upon a line passing through 

 the apex and perpendicular to the dark band shown 

 in Fig. 5. which marks the region of no stress. They 

 are. therefore, approximately consistent with Michell's 

 theory of stress in a wedge, 1 and have been shown 



1 Proceedings of the London Mathematical Society, vol. xxxiv., 1902, 

 and Love's " theory of Elasticity," 2nd edition, pp. 208-209. - 



experimentally, in the paper referred to above, to be 

 in good agreement therewith along the line of action 

 of the applied force. The stress system is found to be 

 almost entirely radial and expressed by 



-, cos (a - <f>) 



rr= —c . — — - , 

 r 



along this line — where a is the inclination of the outer 

 face to the line of centres of the colour bands, and </> is 

 the inclination of the applied force to the same face. 

 Along each colour band ft is practically constant. The 

 value of the constant c is also expressible in terms of 

 the force P, the angle a and the angle y of the wedge. 

 The stress system in the case when the material is 

 being torn off by the action of the raking face of the 

 wedge angle of the tool has not, so far, been made out. 

 Experiment shows, however, that it is of a more 

 complicated type, especially when the action is accom- 

 panied by the building up of a secondary wedge on the 

 tool from the material torn off in a manner which is 

 familiar to those engaged' in machinery operations 

 involving heavy cuts. 



The New Building of the National Academy of Sciences, U.S.A. 

 Bv Dr. C. D. Walcott. 1 



IN 1863 Henry Wilson, United States Senator from 

 Massachusetts, asked a number of men eminent 

 in science to come together to form an organisation by 

 which the scientific strength of the country might be 

 brought to the aid of the government. This meeting 

 was directly the result of an Act of Congress passed 

 March 3. 1863, incorporating the National Academy 

 of Sciences of the United States of America. While 

 Senator Wilson presumably had aid and suggestions 

 from the incorporators, the bill had its inception with, 

 and was drawn by him, and did not incorporate the 

 Academy in any state or territory, or in the District 

 of Columbia. It seems to have been his idea that 

 the Academy should be national in its broadest 

 sens :. 



The Academy has held its annual meetings in 

 Washington at the Smithsonian Institution and its 

 autumn meetings in other cities. Joseph Henry was 

 president for many years and at the same time secre- 

 tary of the Institution. The records and library of 

 the Academy have been stored in several hundred 

 boxes at the Institution, awaiting such time as the 

 Academy may have a building of its own where this 

 material can be made available. 



The semi-centennial in 1913 gave new life to the 

 acth ities of the Academy, and the foreign secretary, 

 Dr. George E. Hale, proposed then that the Academy 

 should have a home. He prepared tentative plans 

 and had them put in shape by an architect. These 

 plans provided laboratories and a library for the 

 use of the Academy and resident men of science for 

 research work. 



The project was not to be long delayed, for the 

 world war coming in 19 14 changed and broadened 

 the thought of the world. What started to be a battle 

 of armed forces turned to competition between the 

 countries at war in creative scientific research, looking 



1 Paper read before the National Academy of Sciences on April 24. 

 NO. 2751, VOL. I I o] 



to the destruction of masses instead of individuals. 

 This led to the need in the United States of a body that 

 could bring together the most able men in the fields 

 of science for the solution of war problems. Dr. Hale, 

 conceiving the need for such a service long before it 

 was an actual necessity, proposed that the Academy 

 take preliminary steps in the organisation of the 

 scientific resources of the United States, and this was 

 the beginning of the National Research Council which 

 rendered such effective service at the request of the 

 President of the United States during the war. 



Appreciation of this service from the Academy was 

 shown in an executive order issued by President Wilson, 

 directing the National Academy of Sciences to continue 

 the Council. Under this order the Research Council 

 was reorganised on a permanent peace basis as an 

 agent of the Academy, and the need of the Academy 

 for a home was accentuated. Dr. Hale's precious plans 

 were discussed at length, but the question of available 

 funds continued. The quarters in the Smithsonian 

 Institution, already too crowded, could not afford 

 room for this new body, and temporary space elsewhere 

 was found in the Munsey Building ; then a residence 

 at 1 6th and L Streets, having twenty-one rooms, was 

 secured. A little later a larger building at 16th and 

 M Streets was occupied, until the present location at 

 17th and Massachusetts Avenue was leased. 



Early in these lenewed activities strenuous efforts 

 were made to secure a permanent endowment and 

 money for a building for the Academy, and a suggestion 

 was made to the Carnegie Corporation of an endow- 

 ment and building for the Academy and Research 

 Council, resulting in an offer of 5,000,000 dollars, 

 provided the Academy would secure a site and present 

 satisfactory plans. The amount needed for the 

 purchase of this site was apportioned, so that the 

 entire country might have a part in the great enter- 

 prise. The raising of funds for the purchase of the 



