Family and guests at Aenny Catzenstein nee Gottschalk's 80th birthday; London.

Front row l-r: Beatrice Durand, Francine Durand and Aenny Catzenstein, the boys are Ara-Serge Donabedian and Patrick Matthiesen and the adults are Susan Prior, Francis Matthiesen, Maren Matthiesen, Nino Fabri and Olga Matthiesen,

Family and guests at Aenny Catzenstein nee Gottschalk's 80th birthday party; London.

Dinner scene with Franz Mattheisen left, daughter Susan Mattheisen next to him, next daughter Maren Matthiesen, his wife Olga Matthiesen at the end of the table. Beatrice Durand is facing the camera

Family and guests at Aenny Catzenstein nee Gottschalk's 80th birthday; London.

Front row l-r: Francine Durand, Beatrice Durand and Aenny Catzenstein, the boys are Ara-Serge Donabedian and Patrick Matthiesen and the adults are Susan Prior, Francis Matthiesen, Maren Matthiesen, Nino Fabri and Olga Matthiesen,

Exterior view of Martin Goldschmidt's business; Kurfuerstendamm 34, Berlin W.15 Portraits Men

Born 1879?; Married September 2, 1903 in Leipzig to Paula Harmelin; Father of Henry H. Goldschmidt Gould and Ruth Augusta Beatrice Goldschmidt

Martin Goldschmidt reading on a park bench Portraits Men

Handwritten postcard addressed to Ruth Goldschmidt in Italy and dated 1937 from Zurich

Surface waves in the presence of external high frequency fields

The system equations of a collisionless, unmagnetized plasma, contained in a box where a high frequency (h.f.1 electric field is incident, are solved in the electrostatic approximation. The surface modes of the plasma in the semi-infinite and box geometry are investigated. In the high frequency limit, the mode frequencies are not significantly changed by the h.f. field but their group velocities can be quite different. Two long wavelength low frequency modes, which are not excited in the absence of h.f. field, are found. These modes are true surface modes (decaying on one wavelength from the surface) unlike the only low frequency ion acoustic mode in the zero field case. In the short wavelength limit the low frequency mode occurs at &/2, oi being the ion plasma frequency, a result similar to the case of no h.f. field.

Rose Wergert nee Herz on deck of the ship New York.

Rose, sister of Fred and Beatrice Herz

Studio portrait of Rose Wergert nee Herz.

Rose, sister of Fred and Beatrice Herz

Photographic reproduction of charcoal portrait of Arnold Gottlieb Portraits Men

Signed by artist bottom right

Family and guests at Aenny Catzenstein nee Gottschalk's 80th birthday; London.

Front row l-r: Beatrice Durand, Francine Durand and Aenny Catzenstein, the boys are Ara-Serge Donabedian and Patrick Matthiesen and the adults are Susan Prior, Francis Matthiesen, Maren Matthiesen, Nino Fabri and Olga Matthiesen,

Family and guests at Aenny Catzenstein nee Gottschalk's 80th birthday party; London.

Dinner scene with Franz Mattheisen left, daughter Susan Mattheisen next to him, next daughter Maren Matthiesen, his wife Olga Matthiesen at the end of the table. Beatrice Durand is facing the camera

Family and guests at Aenny Catzenstein nee Gottschalk's 80th birthday; London.

Front row l-r: Francine Durand, Beatrice Durand and Aenny Catzenstein, the boys are Ara-Serge Donabedian and Patrick Matthiesen and the adults are Susan Prior, Francis Matthiesen, Maren Matthiesen, Nino Fabri and Olga Matthiesen,

Rose Wergert nee Herz on deck of the ship New York.

Rose, sister of Fred and Beatrice Herz