Mr.Howlett, in the paper I have quoted from above, describes a very satisfactory method, which those who are anxious to devote themselves seriously to solar observation will do well to study.
It is necessary that the observer should be able to determine approximately where the sun's equator is situated at the time of any observation, in order that he may assign to any spot or set of spots its true position in relation to solar longitude and latitude.

Mr.Howlett shows how this may be done by three observations of the sun made at any fixed hour on successive days.

Perhaps the following method will serve the purpose of the general observer sufficiently well:-- The hour at which the sun crosses the meridian must be taken for the special observation now to be described.

This hour can always be learnt from 'Dietrichsen's Almanac'; but noon, civil time, is near enough for practical purposes.

Now it is necessary first to know the position of the ecliptic with reference to the celestial equator.