ARCH

==== An arc is a curve -shaped structure, wich supports the weight of a material on an open space  . The arch is considered as the evolution of the  post - and -  lintel technique  . ====

The Arc has several  advantages  over the post  <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">-and - <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">lintel <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">technique  <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">, such as : <span style="font-family: Arial,sans-serif;">
 * ==== <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">An arch allows a <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">much longer span than span of the post <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">- and- <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">lintel .====
 * ====<span style="font-family: Arial,sans-serif; font-size: 16px; line-height: 18px;">Also an arch can support a weight much higher than the weight that can support a lintel. ====

====** <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">There are six types of arcs <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">: **====

====<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level1 lfo1; text-align: justify; text-indent: -.25in;"><span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">1. A roman arch ==== ====<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level1 lfo1; text-align: justify; text-indent: -.25in;"><span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">2. The pointed or gothic arch ==== ====<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level1 lfo1; text-align: justify; text-indent: -.25in;"><span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">3. A syrian or segmental arch ==== ====<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level1 lfo1; text-align: justify; text-indent: -.25in;"><span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">4. Tudor arches ==== ====<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level1 lfo1; text-align: justify; text-indent: -.25in;"><span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">5. A flat arch ==== ====<span style="display: block; margin-left: 1.0in; mso-add-space: auto; mso-list: l0 level1 lfo1; text-align: justify; text-indent: -.25in;"><span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">6. A horseshoes arch. ====

====** <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">Parts of a n ** **<span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">arch :** ====


 * ====__ Keystone: __ is a piece of wedge- shaped stone located at the center of the apex of an arch . This piece is very important because this piece supports all weight of the structure .====
 * ==== __ Voussoir :__ are the wedge -shaped stones that are on both sides of the Keystone . ====


 * ====__ <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">Pier <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">: __ <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">is the base on which rests the Keystone and voussoirs  <span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">. ====





**<span style="color: black; font-family: Arial,sans-serif; font-size: 12pt; line-height: 115%;">Arch in the city **