Strange silver marks on English glass bottle with silver nec

I recently acquired a small glass bottle with a silver collar and the attached hallmark has me baffled. I think it’s a Birmingham mark but the anchor is on its side which would be fine for platinum or gold but I’m sure it’s silver. I was wondering if anyone has any information on the marks. Thanks

Brian
new hallmark close up.JPG

This is definitely a Birmingham silver hallmark. The date is 1887 and the maker is Charles May, a fairly prolific maker of, among other things, silver tops for bottles. I don’t know why they decided to put the anchor on its side, but it was almost always so for the date letter cycle 1875-1899 (in fact I don’t think I’ve seen an upright anchor for that cycle at all).

Thank you for the information. I never expected such a quick response. The jar has now been labbelled in my collection accordingly but more important is, I’ve learned the anchore on its side is not that significant.
Cheers
Brian