Secam—A seeing-controlled camera for high-resolution photographs

The basic design of a seeing-controlled camera (SECAM) is described. The camera is currently under construction, and will be used in combination with the 61 cm telescope of the Ruhr-University Bochum at La Silla, Chile.Communication presented at the International Conference on Astrometric Binaries, held on 13–15 June, 1984, at the Remeis-Sternwarte Bamberg, Germany, to commemorate the 200th anniversary of the birth of Friedrich Wilhelm Bessel (1784–1846).     

Abflußereignisse,eine skalenabhängige multiple Antwort von Einzugsgebieten auf Niederschläge

Flood Events, a Multiple Basin Response to Precipitation Events at Different Scales Results in the small catchment of the Kartelbornsbach have shown that summer events lead to typical types of flood waves that can be classified according to their response patterns. Differences to this pattern are due to the precipitation amount and duration and in some times to the pre-event moisture of the soil. The results show further that the Kartelbornsbach catchment can be considered as a block system where spatial differences are responsible for the basic pattern of the reaction but not for differences between flood events. Small catchments are excellent tools for relatively inexpensive hydrological and hydrochemical research on streamflow generation mechanisms. With increasing size of the basin the response becomes less clear, because the spatial distribution of rainfall and the distance of delivering areas from the sampling station mask or modify the type of response. Although the main flow components may not change, there is a considerable shift in the composition of water quality, because the increase of travel time does not affect all flow components at the same rate.     

On the relationship between hydrographs and chemographs

The spatial representativeness of gauging stations was investigated in two low‐mountainous river basins near the city of Trier, southwest Germany. Longitudinal profiles during low and high flow conditions were sampled in order to identify sources of solutes and to characterize the alteration of flood wave properties during its travel downstream. Numerous hydrographs and chemographs of natural flood events were analysed in detail. Additionally, artificial flood events were investigated to study in‐channel transport processes. During dry weather conditions the gauging station was only representative for a short river segment upstream, owing to discharge and solute concentrations of sources contiguous to the measurement site. During artificial flood events the kinematic wave velocity was considerably faster than the movement of water body and solutes, refuting the idea of a simple mixing process of individual runoff components. Depending on hydrological boundary conditions, the wave at a specific gauge could be entirely composed of old in‐channel water, which notably reduces the spatial representativeness of a sampling site. Natural flood events were characterized by a superimposition of local overland flow, riparian water and the kinematic wave process comprising the downstream conveyance of solutes. Summer floods in particular were marked by a chronological occurrence of distinct individual runoff components originating only from a few contributing areas adjacent to the stream and gauge. Thus, the representativeness of a gauge for processes in the whole basin depends on the distance of the nearest significant source to the station. The consequence of our study is that the assumptions of mixing models are not satisfied in river basins larger than 3 km². Copyright © 2006 John Wiley & Sons, Ltd.     

Über ein Datolithvorkommen am Basaltkontakt im Kaliwerk Buggingen (Südbaden)

Zusammenfassung Kleine Datolith-Knöllehen wurden unmittelbar auf dem Kontakt von Ankaratrit-Gängen mit dem Unteren Kalilager auf dem Kaliwerk Buggingen aus hydrothermalen Lösungen im Gefolge der Gangbildung und vielleicht im Zusammenhang mit der Serpentinisierung gebildet. Ihre Bildungstemperatur ließ sich aus der volumenkonstanten Umwandlung der Sylvinite in Hallt-Gesteine im Kontaktbereich zu etwa 300° C abschätzen.

---

Small spherolites of datolite occur immediately on the contact of the lower potash seam with cross-cutting ankaratrite-dikes in the mine of Buggingen, southern Baden. They are hydrothermal in origin and perhaps connected with the serpentinization of the ankaratrites. Their temperature of formation of about 300° C was estimated from the fact, that the volum of the potash seam remained constant during the metasomatic replacement of sylvite by halite in the neighbourhood of the dikes.

---

---

Herrn Prof. Dr.C. W. Correns zum 70. Geburtstag gewidmet.     

Zur Wolkenstatistik des Planeten Mars

The distribution of the Martian clouds observed at Hamburg Observatory during the oppositions 1948, 1958, 1963, 1965 and 1967 is graphically displayed. The number of clouds per degree longitude shows a positive correlation with the 21°.5 North radar-altitude.     

Investigating the transport dynamics and the properties of bedload material with a hydro‐acoustic measuring system

This article deals with the following two questions. Are acoustic measurements in running waters appropriate for a highly resolved investigation of the bedload transport? Which characterizations of the bedload regarding mass and shape are possible via the acoustic signals? The signals were recorded by means of data recorders (Tascam Inc. DAP1 Portable Data Recorder) and hydrophones (International Transducer Corp. ITC‐4001 A). The ITC‐4001 is a shallow water omnidirectional transducer containing a flexural disc transducer utilizing Channelite‐5400 ceramics mounted in a rugged corrosion‐resistant housing. These hydrophones were screwed onto the bottom side of stainless steel plates, serving as a contact surface for the bedload in motion above them. After more than 100 series of tests in the laboratory, which indicated the basic relations between the dimension, shape and weight of the bedload and the resulting signal, field tests of the measuring system were conducted. By artificially produced flood waves in the small brooks Riverisbach, Olewiger Bach and by a winter flood wave in the River Moselle, it is possible to elaborate similar structures of the signal course of the bedload movement. The highest transport rates can be observed at the beginning of the increasing limbs and behind the peaks of the waves. At the beginning of the waves, the increasing transport power of the water and the loose material can be considered as the cause for this result. The high stream velocity behind the wave peaks explains the increase in the bedload transport so that material from the channel beds is unfastened and will be mobilized. The characterization of the bedload regarding the shape and mass is still limited regarding the field measurements and could be solved only for homogeneous grain sizes and single stones under laboratory conditions. Copyright © 2007 John Wiley & Sons, Ltd.     

Zur Bewegung der Kondensationen im Schweif des Kometen MOREHOUSE 1908 III

This paper deals with the motion of condensations within the tail of Comet Morehouse 1908 III as derived from Greenwich- and Yerkes-photographs. For the vicinity of the nucleus the following results are obtained: