Thanks to a very helpful "Kiwidave" I was able to get the following info:
Hi this mark is from the company of Johnson & Jorgensen who set up on the Thames c1884 they both moved from Norway as life there was very hard, the mark you have could date anywhere from 1884 up to the 1930,s many inks have a stylised version which is all there is room for basically an angular C shape with a line half way up to form a 2 pronged fork. The company is still going and is now part of Thameside Packaging on the Thames in London, the original company owned about 14 glass factories across Europe all making bottles to order. Many bottles and jars have MADE IN BELGIUM or BOTTLE MADE IN WESTPHALIA sometimes with the trident mark. Hope that helps?
Just as an aside to the above many of the glass prizes given at sporting events such as decanters and rose bowls are made by this company.