The preparation and properties of pure iron alloys: II. Magnetic properties of iron-carbon alloys as affected by heat treatment and carbon content

✍ Scribed by W.L. Cheney.

• Publisher: Elsevier Science
• Year: 1923
• Tongue: English
• Weight: 151 KB
• Volume: 195
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(23)90239-5

✦ Synopsis

Feb., t923.] U.S. BUREAU OF STaXDaRDS NOTI.ZS.

253

and to formulate a statement of the conditions under which the spherical aberrations of two thin lenses will compensate one another. This last is confined to the simplest case, in which the lenses are close together. The treatment is in part analytical, in part graphical.

In addition, there is included in this paper a graphical solution of the problem as to the conditions under which a two-piece lens may be achromatic, free from axial spherical aberration, cemented, and free from coma, and the shapes of the lenses necessary to satisfy these different conditions are shown. The effect of a slight change in the shape of the lenses is also indicated.

It is not expected that any of the material is really new, but the author knows of no place where the information given may be readily obtained, even piecemeal.