Archive for 2011

Gilbert: Magnetic Disagreements

Thursday, May 5th, 2011

But here we notice another curious fact … * [ZB Magnet 2] William Gilbert, De Magnete (London: Petrus Short, 1600), Zentralbibliothek Zürich, Alte Drucke und Rara, XVI.28, p. 133.

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Wednesday, May 4th, 2011

Judith Albert

William Gilbert: Dip or Inclination

Wednesday, May 4th, 2011

Magnetic needles, pointers, rods or wire have a tendency toward the earth’ s centre, the so  called magnetic dip or inclination. Inclination variers. Here a magnetic wire in a cork shows its dip in a bowl filled with water. [ZB Magnet 2] William Gilbert, De Magnete (London: Petrus Short, 1600), Zentralbibliothek Zürich, Alte Drucke und Rara, XVI.28, p. 203.

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SPEEDI*

Tuesday, May 3rd, 2011


Barbara Ellmerer

*System for Prediction of Environmental Emergency Dose
SPEEDI, designed to predict the dispersal of radioactive materials based on forecasts by ERSS, is likely to have delayed the effective evacuation of residents in Fukushima Prefecture. The systems’ failure casts doubt on the government’s disaster-prevention policy, which said that the systems should be used to analyze and predict the amount and spread of radioactive material into the environment during a nuclear crisis.

William Gilbert: Deviation

Monday, May 2nd, 2011

Long loadstone with versoria. Versoria deviate according to the distance from the middle or equator of the loadstone (CD). The deviations are greater the greater the distance of the versoria is from the equator. [ZB Magnet 2] William Gilbert, De Magnete (London: Petrus Short, 1600), Zentralbibliothek Zürich, Alte Drucke und Rara, XVI.28, p. 164.

William Gilbert: Terrella with a weak part which is marked with cross-lines.

Thursday, April 28th, 2011

[ZB Magnet 2] William Gilbert, De Magnete (London: Petrus Short, 1600), Zentralbibliothek Zürich, Alte Drucke und Rara, XVI.28, p. 155.
AB is a terrella imperfect in parts and of unequal power on the circumference. The needles H and L vary, because they are placed in a decayed part and incline towards the sound parts (where the needles C, D, E, F are placed). Needle O does not deviate because it is placed in the middle of the decayed part.

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Obtaining magnetic direction

Wednesday, April 27th, 2011

Iron will obtain north-south direction when it is hammered and heated properly: “Let the smith stand facing north, with back to the south, so that as he hammers the red-hot iron it may have a motion of extension northward.” (Gilbert, De Magnete (translated by Mottelay) p. 211ff) [ZB Magnet 2] William Gilbert, De Magnete (London: Petrus Short, 1600), Zentralbibliothek Zürich, Alte Drucke und Rara, XVI.28, p. 139.

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Wednesday, April 27th, 2011

Judith Albert

The agreement of the magnetic form is seen in the sphapes of plants

Tuesday, April 26th, 2011


[ZB Magnet 2] William Gilbert, De Magnete (London: Petrus Short, 1600), Zentralbibliothek Zürich, Alte Drucke und Rara, XVI.28, p. 130f.

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Monday, April 25th, 2011