hemispherical - conical Greek-Roman sundial

[ronit maoz]

I am interested in the above mentioned types of sundial.
1.Where was the gnomon placed un relation to the hour marked stone?
2.Was there any indication as to the lattitude in that type of sundial.
3. What is the difference between the hemispherical and the conical type?
4. What kind of scientific  knowledge did a maker have to possess in order
to make such a dial?
5. What kind of knowledge did the user have to possess?