[41.] Demonstration.

[42.] Remarks.

[43.] Method V.

[44.] Operation, Without Compaſſes.

[45.] Demonstration.

[46.] Remark.

[47.] Corollary.

[48.] Method VI.

[49.] Operation.

[50.] Demonstration.

[51.] Remarks.

[52.] Corollary.

[53.] Problem II.

[54.] Remark.

[55.] Problem III.

[56.] Method. II.

[57.] Problem IV.

[58.] Example I.

[59.] Example II.

[60.] Remarks.

[61.] Example III. 48. To throw a circle into Perſpective.

[62.] Remarks.

[63.] Prob. V. 50. To find the Repreſentation of a Point, elevated above the Geometrical Planc.

[64.] Operation.

[65.] Demonstration.

[66.] Prob. VI. 52. To throm a Pyramid, or Cone, into Perſpective.

[67.] 53. To determine the viſible Part of the Baſe of a Cone.

[68.] Operation.

[69.] Demonstration.

[70.] Remarks.