Item 1 - In Livy I 18,6-10 augur’s templum in aëre is most likely oriented southward, just like Varro’s templum in caelo (L.L. VII 6-8); yet Varro’s templum in caelo and templum in terris must not be confused with Livy’s templum in aëre. Livy’s sentence “prospectu in urbem agrumque capto” concerns the orientation, not the founding of the templum in aëre.
Item 2 - Looking into Varro’s account (L.L. VII, 8-9), it comes out that Varro’s templum in terris corresponds with Livy’s signum (I 18, 8); it is delimited by two trees in the middle of the templum in aëre and coincide with the oxyopic center of human field of vision.
Item 3 - Although Romans might have used the Etruscan templum, they most likely used the templum in aëre both for the observation of lightnings and the observation of birds.
Item 4.1 - The phrases “in urbem agrumque” (Liv. I 18,7) and “urbemque et agros” (Cic., De Leg. II 21) can not mean pomerium.
Item 4.2 - In the tale about Attus Navius’ vineyard (Cic. De Div. I 31; Dion.Hal. Ant.Rom. III 70, 2-3) some scholars have erroneously confused the vineyard with the templum in aëre.