Saint Magnus Erlendsson, Earl of Orkney, sometimes known as Magnus the Martyr, was Earl of Orkney from 1106 to about 1115. Magnus's grandparents, Earl Thorfinn and his wife Ingibiorg Finnsdottir, had two sons and Paul, who were twins. Through Ingibiorg's father Finn Arnesson and his wife, the family was related to the Norwegian Kings Olav II and Harald II. Magnus's story is told in three Norse sagas: Orkneyinga saga; the Orkneyinga Saga was first written down around the year 1200, some 80–90 years after the death of Magnus, by an unknown Icelandic author. An abridgement of the Magnús saga skemmri makes up chapters 39–55 of the Orkneyinga Saga. Magnús saga lengri contains additions to the original by a "Master Rodbert" dated to the period 1136–70. Of the three texts Vigfusson considers the shorter saga to be the "best authority", noting that it is "of ecclesiastical origin" and "composed with pious intent" rather than to "satisfy a love of good tales"; as is the case for medieval saints' tales a short book of miracles is appended to both the shorter and longer lives, although they contain somewhat different material.

There is a surviving Latin account of Magnus's life, the Legenda de sancto Magno, other material in the Brevarium Aberdonense of 1509/10, no doubt based on the missing Vita by the above magister Rodbert - part of, included in the Magnús saga lengri. Magnus was the first son of Erlend Thorfinnsson, Earl of Orkney and Thora, a daughter of Sumarlidi Ospaksson, they had one other son and two daughters and Cecilia. Erlend had a natural daughter called Jaddvor. Paul and Erlend remained on friendly terms until their children grew to adulthood, due to the rivalry between Haakon Paulsson and Erling Erlendsson. Both are described as talented but quarrelsome and arrogant. Magnus, by contrast, was "a quiet sort of man". Haakon believed himself to be the most highly-born of the cousins and wanted to be seen as the foremost amongst his kin, but Erling was not one to back down; the fathers did their best to reach a settlement but it became clear that they were both favouring their own offspring and the earldom was divided into two distinct territories.

Haakon Paulsson went on a long journey to Scandinavia, latterly staying with his kinsman, Magnus Barefoot the king of Norway. Whilst there he heard that his father Paul had handed over control of Orkney to Earl Erlend and his sons and that after a substantial period of peace the people of Orkney were not keen to see Haakon returning, he therefore asked King Magnus for help in the hope of obtaining the earldom for himself. Haakon suggested to the king that he take back direct control of Orkney as a base for raiding further afield. Magnus was persuaded and in 1098 he launched a major campaign, taking his 8 year old son Sigurd with him. However, King Magnus had designs, he took possession of the islands, deposing both Erlend and Paul Thorfinsson who were sent away to Norway as prisoners and his cousins Magnus and Erling Erlendsson were taken by King Magnus as hostages and Sigurd was installed as the nominal earl. Sigurd's rule was aided with Haakon as a member of this group. From Orkney, King Magnus set out on a raiding expedition along the west coast of Scotland and into the Irish Sea.

According to the Orkneyinga Saga, Magnus had a reputation for piety and gentleness, which the Norwegians viewed as cowardice. He refused to fight in a Viking raid in Anglesey, because of his religious convictions, instead stayed on board the ship during the Battle of Menai Straits, singing psalms, his brother Erling died while campaigning with King Magnus, either in Ulster. Magnus was obliged to take refuge in Scotland, but returned to Orkney in 1105 and disputed the succession with his cousin Haakon. Having failed to reach an agreement, he sought help from King Eystein I of Norway, who granted him the earldom of Orkney and he ruled jointly and amicably with Haakon until 1114. However, the followers of the two earls fell out, the sides met at the Thing on the Orkney mainland, ready to do battle. Peace was negotiated and the Earls arranged to meet each other on the island of Egilsay at Easter, each bringing only two ships. Magnus arrived with his two ships, but Haakon treacherously turned up with eight ships.

Magnus took refuge in the island's church overnight, but the following day he was captured and offered to go into exile or prison, but an assembly of chieftains, tired of joint rule, insisted that one earl must die. Haakon's standard bearer, refused to execute Magnus, an angry Haakon made his cook Lifolf kill Magnus by striking him on the head with an axe, it was said. According to the sagas, the martyrdom took place on 16 April; the year is given as 1115, but this is impossible as 16 April fell before Easter that year. Sigurd Towrie follows Orkney Historian Gregor Lamb in placing the death of Magnus in 1118; the best authorities now give the date at 1117 and his 900th anniversary was commemorated in his Cathedral in Kirkwall in Orkney in 2017. Magnus was first buried on the spot. According to his legend, the rocky area around his grave miraculously became a green field. Thora, Magnus' mother, asked Haakon to allow her to bury him in a Church. Haakon gave his permission and Magnus was buried at Christchurch at Birsay.

There were numerous reports of miraculous healings. William the Old, Bishop of Orkney, warned that it was "heresy to go about with such tales" an

Brachylaena discolor is a species of flowering plant in the aster family, Asteraceae. It is native to Africa, where it occurs in Mozambique, South Africa, Eswatini, its common names include coastal silver oak. This species is a shrub or tree up to about 10 meters tall, but known to reach 27 to 29 meters at times; the branches are brown or purple-tinged, hairy when new. The leaves are oval or oblong and up to 12 centimeters long, they are smooth-edged to toothed to spine-toothed. They are hairless and a shiny dull green on top and grayish hairy underneath. Flowers are borne in large panicles at shorter panicles in the leaf axils; the species is dioecious, with flower heads that look like "plump shaving brushes". Male plants have heads with a single layer of pappus hairs. Female heads have multiple layers of pappus hairs; the plant grows in coastal forests, on the edges of mangroves, along rivers. The flowers attract insects and birds, it is a good honey plant. The leaves may be browsed by antelopes such as nyala and duikers.

This species has become naturalized in Queensland, is a potential weed. The yellow wood is strong and has been used for many purposes, including the construction of boats, fences and roofing, axles and knobkierries, it is considered a valuable carving wood. The ash was used in the production of soap; the plant was used medicinally by European settlers. It has been used to treat kidney conditions, gastrointestinal bleeding, intestinal parasites, chest pain, it is cultivated as an ornamental plant for gardens and landscaping. It can be used to stabilize dunes; some authors divide the species into two varieties, var. discolor and var. transvaalensis. Others treat var. transvaalensis as Brachylaena transvaalensis, a separate species. Its leaves have a distinctive shape and its flower heads are smaller and different in morphology. Maputaland-Pondoland-Albany Hotspot Brachylaena discolor. JSTOR Global Plants

The spinning drop method is one of the methods used to measure interfacial tension. Measurements are carried out in a rotating horizontal tube. A drop of a less dense liquid or a gas bubble is placed inside the fluid. Since the rotation of the horizontal tube creates a centrifugal force towards the tube walls, the liquid drop will start to deform into an elongated shape; the surface tension between the two liquids can be derived from the shape of the drop at this equilibrium point. A device used for such measurements is called a “spinning drop tensiometer”; the spinning drop method is preferred for the accurate measurements of surface tensions below 10−2 mN/m. It refers to either using the fluids with low interfacial tension or working at high angular velocities; this method is used in many different applications such as measuring the interfacial tension of polymer blends and copolymers. An approximate theory was developed by Bernard Vonnegut in 1942 to measure the surface tension of the fluids, based on the principle that the interfacial tension and centrifugal forces are balanced at mechanical equilibrium.

This theory assumes that the droplet's length L is much greater than its radius R, so that it may be approximated as a straight circular cylinder. The relation between the surface tension and angular velocity of a droplet can be obtained in different ways. One of them involves considering the total mechanical energy of the droplet as the summation of its kinetic energy and its surface energy: E = E k + γ s The kinetic energy of a cylinder of length L and radius R rotating about its central axis is given by E k = 1 2 I ω 2 = 1 4 m R 2 ω 2 in which I = 1 2 m R 2 is the moment of inertia of a cylinder rotating about its central axis and ω is its angular velocity; the surface energy of the droplet is given by γ s = 2 π L R σ = 2 V R σ in which V is the constant volume of the droplet and σ is the interfacial tension. The total mechanical energy of the droplet is E = E k + γ s = 1 4 Δ ρ V R 2 ω 2 + 2 V R σ in which Δρ is the difference between the densities of the droplet and of the surrounding fluid.

At mechanical equilibrium, the mechanical energy is minimized, thus d E d R = 0 = 1 2 Δ ρ V R ω 2 − 2 V R 2 σ Substituting in V = π L R 2 for a cylinder and solving this relation for interfacial tension yields σ = Δ ρ ω 2 4 R 3 This equation is known as Vonnegut’s expression. Interfacial tension of any liquid that gives a shape close to a cylinder at steady state, can be estimated using this equation; the straight cylindrical shape will always develop for sufficiently high ω. Once this shape has developed, further increasing ω will decrease R while increasing L keeping LR2 fixed to meet conservation of volume; the full mathematical analysis on the shape of spinning drops was done by others. Progress in numerical algorithms and available computing resources turned solving the non linear implicit parameter equations to a pretty much'common' task, tackled by various authors and companies; the results are proving. The spinning drop method is convenient compared to other used methods for obtaining interfacial tension, because contact angle measurement is not required.

Another advantage of the spinning drop method is that it is not necessary to estimate the curvature at the interface, which entails complexities associated with shape of the fluid drop. On the other hand, this theory suggested by Vonnegut, is restricted with the rotational velocity; the spinning drop method is not expected to give accurate results for high surface tension measurements, since the centrifugal force, required to maintain the drop in a cylindrical shape is much higher in the case of liquids that have high interfacial tensions