Activating HTTPS

Last year in Site Stats and Security (July 2017), I noted,

HTTPS as a ranking signal • Is this the reason for the drop in the number of daily visitors on my site? [...] That promises more work that has nothing to do with the content of the site, but I need to look into it at some time in the months ahead.

It turns out that the site already has HTTPS security (SSL) enabled.

Top: https://www.mark-weeks.com/

Bottom: Firefox 'More Information'

When I click on one of my links in the top half, the next page reverts to HTTP, but I can activate HTTPS by simply changing the URL. Subsequent pages retain HTTPS unless they are loaded from a different directory.

My domain host tells me I need to 'Create a 301 Redirect to Enforce your SSL certificate'. I'll look at that in another post.