The name Trade Mark London refers to the historic F. Barker & Son trade mark, which is a stylised superimposition of the characters F, B, & S set inside a triangle, each side made of one of the three words, TRADE, MARK, LONDON.  The name does not refer to my geographical location

Valuations are charged at GBP 25 - payment in advance - not refundable in the event that the instrument proves to be counterfeit and worthless The valuation will come with all other useful information I can provide up to a maximum of one hour of my time.

WHY BUY FROM THIS SITE? People often ask why they should consider buying from The answer is simply there is no risk for the customer.  I offer guaranteed satisfaction or a full refund. When you buy compasses and other scientific instruments from sites such as eBay and various dealers in the Internet you can never be sure what you are buying, and sadly many dealers or online auction sellers do not offer a guarantee.   Many people buy compasses, such as MkIII liquid prismatic compasses, from auction sites and then send them to me for servicing, and very often I have to send the item back and explain to the customer that the instrument is unserviceable.   Over the decades many compasses have been "repaired" by well-intentioned amateurs who have used totally unsuitable materials to effect the repairs.  Super glue and putty, for example, are often used to seal the capsule, and totally unsuitable fluids are used, and as a result the compass is rendered permanently unserviceable and worthless, even though cosmetically it seems in good condition.   It can be an unpleasant surprise for somebody who has just spent £100 or more on a compass to find that either it will cost £130 to make it work, or that it cannot be made to work.  Often such buyers have no recourse as they have bought from a disreputable source that offers no guarantee. MY COMPASSES AND INSTRUMENTS ARE GUARANTEED TO BE EXACTLY AS DESCRIBED AND WE OFFER AN UNCONDITIONAL MONEY-BACK GUARANTEE as long as the compass is returned to us immediately in the condition I sent it. If my compasses are described as fully serviced it means they are mechanically "as new", i.e. in excellent working condition and suitable for actual use. You may pay a bit more buying your items from, but that is because I take the risk, I source the items, I service them, I guarantee them, and YOU enjoy the rewards of my hard work.

Immediately after sending a message, if you have entered your own email address correctly you will see a confirmation at the top of the page saying it was sent successfully. Occasionally, however, the authors of the messages don't take as much care as they could when they write their own email addresses, and without a correct email address I simply cannot reply.  So, if you do not receive a reply within 24 hours please check carefully that you wrote your email address correctly, without gaps, without missing letters and with the dots in the right place and that you complied with the email conditions that you read prior to sending the email.
I will not reply to emails that are screened by a third party filtering system. If you expect me to go and fill in a form on a website in order to allow me to reply to you, then think again. If you want a reply from me please have the courtesy to use an email address that I can reply to.


Firstly, ensure your PayPal is set to give your shipping address - without your address I do not know where to send the item.
In the "Shop" page find the item you wish to purchase and click on "Add To Cart".  Then scroll to the bottom of the page and click on "View Cart” or click on the black “Cart” tab on the right of the page, and then, if your shopping basket contains what you intended to order just click on the “PayPal” button, and a PayPal log in page will appear. This page is in Italian, Italy seems to be the only country in the world that doesn’t allow its page to open in the recipient’s own language, but just enter your PayPal user name and password in the RIGHT HAND SIDE of the page, even if it’s not in your own language, and you will immediately open your own PayPal account in your own country and in your own language. Please ignore the left hand side of the page; like everything Paypal it is designed to confuse :-) I have asked PayPal to standardise the languages, but they don’t seem to know how.

I really only accept payments through Paypal, but email me if you have a problem with Paypal and we can try and sort out another method.

I DO NOT ACCEPT eCHECK PAYMENT - your PayPal account MUST be backed by a credit card for instant clearance of funds.

When you click on the PayPal button to buy the item, you can either click the PayPal section at the top right of the page, (sadly it’s all in Italian and PayPal Italy don’t have the technology to allow me to display the page in the buyer’s language) where you enter your PayPal username and password, or if you don’t have a PayPal account just fill in the credit card payment form, which, although in Italian, is self-explanatory, and complete the payment. Any problems just email me.


If you have interesting Barker items that you would like to offer in PART EXCHANGE for any of the items I have for sale please email me first with a detailed description of what you have, including a few photographs, and also state what you would like to purchase from the shop and we can then negotiate.
Remember, postage is always included in the price - I do not charge extra for postage - and all items are extremely well packed and posted by Registered, Signed-For mail.
Remember that orders can come in from anywhere in the world at any time so in the event that two people order the same item within moments of each other the order bearing the earlier date and time will take priority.  This may happen quickly and I may not have had time to mark the item as reserved or remove it from sale before other emails arrive, so if you want an item time could be important.



Unfortunately during the George "W" administration the U.S. government started installing radioactivity scanners at all ports of entry to the USA. 

Even though U.S. Law clearly exempts vintage watches, compasses and instruments that contain Radium 226 markers on their dials, the employees at the scanning portals are wilfully ignorant of this exemption and in order to get their statistics higher they are blocking everything, and in certain cases have called in the US Military Haz-Mat team to dispose of the compasses, and then anecdotally sending the addressee an invoice for US$15,000 for removal and destruction of hazardous material.
In the very best cases, after reporting the U.S. postal authorities to the police, through a lawyer, for postal theft, the compasses have been released, but after a delay of up to six months and a lot of irrecoverable expense.
We all thought this paranoia would have ended with the dispatch of George "W", but it has actually got worse under the new administration.
Sadly, for that reason, I and many other dealers outside the USA will now no longer ship to the USA.
I will sell you the item, on condition that you pay for and organise collection of the item from here in Europe, AT YOUR OWN RISK.  Once collected from here you would have no further recourse to me should things go wrong.
Sorry, but you voted for them, so you must live with their decisions… but yours is the ONLY country in the world that blocks import of antique compasses, erroneously quoting your Homeland Protection Laws.


If you have any questions please email me in English, Italian or French, after reading the conditions of email, and I will be happy to help.