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		<title>USGS Multimedia Gallery for tag: Alidade</title>

		<link>http://gallery.usgs.gov/</link>
		<language>en-us</language>
		<managingEditor>OC_Web@usgs.gov (Office of Communications Web Group)</managingEditor>
		
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			<url>http://gallery.usgs.gov/images/USGS.gif</url>
			<title>USGS</title>
			<link>http://gallery.usgs.gov/</link>
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			<item>
				<title><![CDATA[USGS Topographers at Work]]></title>
				<link>http://gallery.usgs.gov/photos/11_23_2009_wbr1UHg76O_11_23_2009_0</link>
				<media:description><![CDATA[Two USGS topographers circa 1925, working with an alidade and plane table. The man on the left is believed to be Roland Whitman Burchard, who was the topographer for the USGS Grand Canyon Expedition of 1923.]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/11_23_2009/wbr1UHg76O_11_23_2009/thumbs/FA063-300.jpg"/>
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			</item>                  

			<item>
				<title><![CDATA[USGS Topographers at Work]]></title>
				<link>http://gallery.usgs.gov/photos/11_23_2009_wbr1UHg76O_11_23_2009_6</link>
				<media:description><![CDATA[Two topographers working with an alidade and plane table. The man on the right is believed to be Roland Whitman Burchard, who was the topographer for the USGS Grand Canyon Expedition of 1923. Author Lewis Freeman described Burchard as a man of "powerful physique, great endurance, and a cool, steady hand."]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/11_23_2009/wbr1UHg76O_11_23_2009/thumbs/FA007-300.jpg"/>
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			</item>                  

			<item>
				<title><![CDATA[USGS Topographer at Work]]></title>
				<link>http://gallery.usgs.gov/photos/11_23_2009_wbr1UHg76O_11_23_2009_7</link>
				<media:description><![CDATA[A USGS topographer works with a plane table and alidade to create a 1:180,000 scale topographic map near Imlay, Nevada. The umbrella is to protect the instrument from temperature variations.]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/11_23_2009/wbr1UHg76O_11_23_2009/thumbs/FA076-600.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/11_23_2009/wbr1UHg76O_11_23_2009/large/FA076-600.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[USGS Topographer at Work]]></title>
				<link>http://gallery.usgs.gov/photos/11_23_2009_wbr1UHg76O_11_23_2009_8</link>
				<media:description><![CDATA[A topographer maps the north half of the Lovelock 1-degree quadrangle in the desert area near Jungo, Nevada. The umbrella protected the instrument from temperature variations.]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/11_23_2009/wbr1UHg76O_11_23_2009/thumbs/FA074-600.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/11_23_2009/wbr1UHg76O_11_23_2009/large/FA074-600.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Cartographers in the Field ]]></title>
				<link>http://gallery.usgs.gov/photos/10_19_2009_jNEq2UThg0_10_19_2009_0</link>
				<media:description><![CDATA[This Depression-era oil painting was created by USGS field man Hal Shelton in 1940. The painting depicts mapping techniques used in the early days of cartography, including an alidade and stadia rod for determining distances and elevations and a plane-table for sketching contour lines. A USGS benchmark is visible near the top. The straight white lines represent survey transects. Note the "US" marking on the canteen: many of the USGS field supplies were obtained from Army surplus. This 4 ft. x 6 ft. painting is on display in the USGS library in Menlo Park, California. ]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/10_19_2009/jNEq2UThg0_10_19_2009/thumbs/painting.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/10_19_2009/jNEq2UThg0_10_19_2009/large/painting.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[High Standard Alidade]]></title>
				<link>http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_0</link>
				<media:description><![CDATA[This alidade consists of straightedges with a rigidly-mounted telescope that can be rotated through the vertical angle ±30. The telescope is set on a high standard or post (4 inches in height) to raise it above the table. The telescope for the high standard is 16 power, inverting type with internal focusing. It is made of brass and was manufactured by Keuffel & Esser Company, New York & New Jersey.
Object ID: USGS-000158]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/thumbs/000158-High_Standard_Alidade.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/large/000158-High_Standard_Alidade.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Gurley Micrometer Alidade]]></title>
				<link>http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_1</link>
				<media:description><![CDATA[Manufactured by W. & L.E. Gurley, Troy, New York. The micrometer attachment us a modification of the tangent screw attached to the horizontal axis of the telescope and used for measuring vertical angles in terms of their tangents. Relatively few of these types of alidades are listed in early 1900s property records of instruments used by the U.S. Geological Survey.
Object ID: USGS-000159]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/thumbs/000159-Gurley_Micrometer_Alidade.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/large/000159-Gurley_Micrometer_Alidade.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Pendulum Self-leveling Alidade]]></title>
				<link>http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_2</link>
				<media:description><![CDATA[This is a telescopic alidade in which a pendulum device, or compensator replaces the conventional bubble for establishing a horizontal reference line from which vertical angles may be measured. Alidades were the primary mapping instrument in the U.S. from about 1865 to the 1980s, when they were replaced by the total station. This alidade was manufactured by Keuffel & Esser Company, New York & New Jersey.
Object ID: USGS-000160]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/thumbs/000160-Pendulum_Self-leveling_Alidade.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/large/000160-Pendulum_Self-leveling_Alidade.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Explorer's Alidade]]></title>
				<link>http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_3</link>
				<media:description><![CDATA[Manufactured by Keuffel & Esser, New York & New Jersey. In this type of alidade, as opposed to the high standard, the telescope mounted close to the straightedge, producing a more compact instrument. A right-angle prism is attached to the eyepiece and permits viewing by looking down. A cylindrical bubble and magnetic compass needle are attached to the base; these are used to level and orient the plane table to its proper position.
Object ID: USGS-000161]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/thumbs/000161-Explorers_Alidade.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/large/000161-Explorers_Alidade.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Telescopic Alidade]]></title>
				<link>http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_4</link>
				<media:description><![CDATA[A high standard alidade; this type of alidade permits direct viewing through the telescope. The level is mounted below the inverting telescope and the base (blade) is solid brass with circular voids. Manufactured by Keuffel & Esser, New York & New Jersey.
Object ID: USGS-000165]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/thumbs/000165-Telescopic_Alidade.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/large/000165-Telescopic_Alidade.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Expedition Alidade with Case]]></title>
				<link>http://gallery.usgs.gov/photos/07_22_2009_j51Qi76Hgb_07_22_2009_38</link>
				<media:description><![CDATA[The rectangular base (blade) features two different types of spirit levels and a trough compass. Manufactured by W. & L.E. Gurley, Troy, New York.
Object ID: USGS-000328]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/thumbs/000328-Expedition_Alidade.jpg"/>
				<media:content type="image/jpeg" url="http://gallery.usgs.gov/images/07_22_2009/j51Qi76Hgb_07_22_2009/large/000328-Expedition_Alidade.jpg"/>
			</item>                  

			<item>
				<title><![CDATA[Open-sight Alidades]]></title>
				<link>http://gallery.usgs.gov/photos/07_20_2009_f3Al15Occ7_07_20_2009_2</link>
				<media:description><![CDATA[Open-sight Alidades. This type of alidade is a straightedge with a sighting device parallel to the edge. Early alidades were simple bars with open sights on either end, while telescopic alidades were introduced in the early 1800s. The examples here of solid brass and an early plastic/wood combination.
Object ID: USGS-000629, USGS-000631]]></media:description>
				<media:thumbnail url="http://gallery.usgs.gov/images/07_20_2009/f3Al15Occ7_07_20_2009/thumbs/000629000631-Alidades.jpg"/>
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			</item>                  

		
                
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