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Colored pencils
410
Astronomical Muscntm.
[Jour. Frank. Inst.,
grOund. For several reasons the latter is preferable. With its points downwards, Jamin claims for the light the following advantages: 1. That of simplicity, since it requires no mechanism and no preliminary preparation ; all is reduced to a support and to carbons. 2. That of mechanical economy, since it succeeds in almost doubling the number of "lights. 3. Increase of illumination, since each of the new lights is nearly twice as powerful as the old. 4. Quality of light, which is more white. 5. A more advantageous arrangement of the poles, which throw their greatest amount of light downwards, where it is required, instead of losing it towards the sky, where it is useless. 6. Economy of the combustible material, since the waste is less in proportion to the size of the carbons.--Nature.
Oolored Pencils.--L. von Faber makes pencils for writing upon glass,, porcelain, metal, etc., as follows--Black: ten parts of lamp black, forty parts white wax, ten parts tallow. White: fort), parts white lead, twenty parts wax, ten parts tallow. Blue : ten parts Berlin blue, twenty parts wax, ten parts tallow. Dark blue : fifteen parts Berlin blue, five parts gum arabic, ten parts tallow. Yellow: ten parts chrome yellow, twenty parts wax, ten parts tallow.--Dingler'~ Journal. C. Astronomical M u s e u m . - - A d m i r a l Mouchey proposes to tbrm an astronomical museum in the Paris Observatory. It is to contain: 1. A collection of the portraits of the astronomers and learned men who have distinguished the observatory since its foundation. 2. A collection of medals relative to the history of astronomy and of the observatory. 3. A collection of designs, engravings and photographs representing celestial bodies and astronomical phenomena. Many of these documents, such as Caasini's beautiful collection of drawings of the moon, have been almost forgotten and are now inaccessible to many astronomers who would feel a great interest in consulting them. 4. A collection as complete and methodical as possible of old astronomical and physical instrument% and of everything which can be found in connection with the base of the metric system. 5. Reduced models of instruments which are now in use in foreign observatories, and of special arrangements in those observatories which appear to be useful. - - Z a Nature. C.
Astronomical Muscntm.
[Jour. Frank. Inst.,
grOund. For several reasons the latter is preferable. With its points downwards, Jamin claims for the light the following advantages: 1. That of simplicity, since it requires no mechanism and no preliminary preparation ; all is reduced to a support and to carbons. 2. That of mechanical economy, since it succeeds in almost doubling the number of "lights. 3. Increase of illumination, since each of the new lights is nearly twice as powerful as the old. 4. Quality of light, which is more white. 5. A more advantageous arrangement of the poles, which throw their greatest amount of light downwards, where it is required, instead of losing it towards the sky, where it is useless. 6. Economy of the combustible material, since the waste is less in proportion to the size of the carbons.--Nature.
Oolored Pencils.--L. von Faber makes pencils for writing upon glass,, porcelain, metal, etc., as follows--Black: ten parts of lamp black, forty parts white wax, ten parts tallow. White: fort), parts white lead, twenty parts wax, ten parts tallow. Blue : ten parts Berlin blue, twenty parts wax, ten parts tallow. Dark blue : fifteen parts Berlin blue, five parts gum arabic, ten parts tallow. Yellow: ten parts chrome yellow, twenty parts wax, ten parts tallow.--Dingler'~ Journal. C. Astronomical M u s e u m . - - A d m i r a l Mouchey proposes to tbrm an astronomical museum in the Paris Observatory. It is to contain: 1. A collection of the portraits of the astronomers and learned men who have distinguished the observatory since its foundation. 2. A collection of medals relative to the history of astronomy and of the observatory. 3. A collection of designs, engravings and photographs representing celestial bodies and astronomical phenomena. Many of these documents, such as Caasini's beautiful collection of drawings of the moon, have been almost forgotten and are now inaccessible to many astronomers who would feel a great interest in consulting them. 4. A collection as complete and methodical as possible of old astronomical and physical instrument% and of everything which can be found in connection with the base of the metric system. 5. Reduced models of instruments which are now in use in foreign observatories, and of special arrangements in those observatories which appear to be useful. - - Z a Nature. C.