This is a Mabie Todd & Bard sterling silver eyedropper from the early years of the 20th century. The presence of the word “Bard” indicates that it was made before 1907 and it can be narrowed down a little further as we will see.
The pen is no longer quite original as some alterations were made at a later date which make it more practical in use. The original “over-and-under” feed was replaced with a ladder feed and the upper part of the early feed was trimmed, as you can see.
Dr Harnett, Margate, was the owner of the the pen. Perhaps it was a very opulent gift on retirement. I hunted him down and found that in 1901 he was mentioned in the list of gifts given to the happy couple at a wedding in Margate. He gave them a silver butter dish, which I’m sure they treasured. He was the Resident Surgeon at the Royal Sea Bathing Hospital and it is recorded that he died in 1905, so the pen must date to that year or those preceding.
For the rest, I’ll let the pictures speak for themselves.
Goodwriterspens's Blog 
I’ll take half a dozen, please…gift card not necessary. What is it about these exquisite pieces of memories of another age that affect my heart rate so much??? Even modified, for which a whipping is in order, the impact of simply seeing it is visceral…
It’s a pity about the replacement of the feed as the pen is now no longer original. However, I think you have to take it in the context of the time and I’m sure that the pen was retrofitted in the 1920s. Whoever had the pen by then did not regard it as a rare and important historical artefact (which it is to us) but simply as an everyday tool, though admittedly a precious one, which he saw the opportunity of improving. There can be no question, of course, that what was done made it a better and more reliable writer than it had been with the old over-and-under feed arrangement.
That’s the context you must take this in. It’s probably 90 or more years since the alteration was made and, judging by the wear, it kept the pen in use for many more years. Otherwise it would almost certainly have been replaced by a more modern pen.