The Commission on Tephrochronology (COT), formed in 1961, comprises geoscientists who characterize, map, and date tephra (volcanic ash) layers and use them as stratigraphic linking and dating tools in geological, palaeoenvironmental, and archaeological research. We review COT's origins and growth and show how its leadership and activities – hosting meetings, supporting ECRs, developing new analytical and dating methods, and publishing volumes – have strongly influenced tephrochronology globally.

Lerwick Observatory in Shetland has recently celebrated its centenary. Measurements of atmospheric electricity were made at the site between 1925 and 1984. The instruments and equipment used for this are discussed and the value of the measurements obtained assessed. A major aspect of the atmospheric electricity work was explaining the dramatic changes which followed the nuclear weapons test period. Although less well known, there are strong parallels with the discovery of the ozone hole.

Kakioka Magnetic Observatory (KMO) has been monitoring the geomagnetic field and electric field at Kakioka, Japan, since 1913. It has promoted a variety of observations and research activities. In 1972, KMO developed the Kakioka Automatic Standard Magnetometer (KASMMER) system, which enabled them to provide geomagnetic field data of the highest quality. Today, KMO operates a network of observatories in Japan and maintains the observations with the longest history in East Asia.

The paper compares the historical context, organization, personnel, conduct, and scientific innovation of the voyages of HMS Challenger (1872–6) and SMS Gazelle (1874–6). Though the expeditions were in many regards similar, the Challenger expedition became famous and is regarded as marking the start of global marine science, while the Gazelle voyage remains almost unknown. Why? A surprising factor may be what we now know as "health and safety" issues.

The term mascon either refers to the fact of a significant gravity anomaly within a celestial body or to a modelling of these gravitational anomalies by localising base functions. The localising base functions that are labelled as mascons include point masses or surface elements based on the simple layer representation. In the case of surface elements, the surface density is constant per mascon, and each localising base function is a two-dimensional step function on the sphere.