I'm new to the forum so hope you can help me learn more about bottles. I have found 3 old bottles this week on the farm where I work, on the river flats of the Northern Wairoa River in Northland New Zealand. This area was first settled by Europeans in the early 1800"s and many artifacts have been found in this area, both pre and post-European periods. This Ayer's Sarsaparilla bottle from Lowell Mass, USA was found when a digger found a small rubbish hole. There was a lot of smashed glass etc and I got 2 bottles out intact. The other bottles look older so are posted on the pre-1900 tread. This one looks newer.
I think you posted the wrong photo on this one, that doesn't look like an Ayer's Sarsaparilla to me. The three bottles could likely be the same age, as American glassmaking was a few decades ahead of UK glassmaking at the time. In general between 1880 and 1940 or so the UK bottles look much older than the US ones.
What is your question about the bottle redhillphil? There's not enough detail in the photo for me to see clearly, but it looks like the mold seams disappear near the upper neck of the bottle, which indicates the lip of the the bottle was hand-tooled. The Owens automatic bottle-making machine was patented in 1904. By 1910 in was adopted by most American bottle producers. "What is It? BEFORE 1900" is likely the proper forum if you are seeking information on the makers of the glass or contents.
However, if you are curious about Sarsaparilla, a wealth of information is available via any browser search. Basically, it is a plant extract similar to root beer that purportedly has numerous health benefits. When you see a character in an old Hollywood western movie say: "I'll have a Sarsaparilla."* they are referring to carbonated drink made from the same extract. Your panel bottle would not likely have contained the carbonated drink being too weak for that purpose.