This is a beautiful jug made by Chamberlains Worcester in about 1810. It is decorated with the very famous "Finger and Thumb" pattern in bright Imari style.
 
These jugs usually came in three sizes for use in the kitchen to hold water or milk; this would have been the smaller size.
 
The Chamberlain factory was founded in the 1780s by Robert Chamberlain, who was responsible for the decoration department in the famous Worcester pottery during the Dr Wall period. He set up his own factory with his son Humphrey, initially buying up stock from Turner's Caughley factory for decoration, but then around 1794 starting to produce their own porcelain. By the year 1800 they had built up a strong reputation, producing wonderful tea and dinner ware for the British and European nobility and becoming a mighty competitor of both the Worcester/Flight & Barr and Grainger factories. In the 1840s the factory merged back with Worcester, which later also bought Grainger and was formed into the later Royal Worcester. 
 
The jug is made of early porcelain, from before the time that bone china became the standard; you can see that the porcelain is slightly greyish.
 
This type of pattern was called the "Japan" style, and it was imitating the beautiful Imari style from Arita, Japan. The style became very popular in the early 19th Century.
 
The "Finger and Thumb" pattern probably has nothing to do with thumbs or fingers, but is an ancient Japanese design. The "fingers" are probably clouds or mist (kasumi in Japanese). This element in Japanese decorations beautifully creates depth in a composition, sometimes forming the ground for more detailed decorations. It can be found in decorations from as early as the  late Heian era in the 13th century, and has often been used in kimono designs.
 
This pattern was also done by John Rose at Coalport. This Chamberlains Worcester version is the more exuberant one.
 
The jug is unmarked, as is usual for this era.
 
CONDITION REPORT The jug is in excellent antique condition without any damage, repairs, crazing and just some minor rubbing. There is a small production mark on the handle, as visible in the last picture.
 
Antique British porcelain is never perfect. Kilns were fired on coal in the 1800s, and this meant that china from that period can have some firing specks from flying particles. British makers were also known for their experimentation, and sometimes this resulted in technically imperfect results. Due to the shrinkage in the kiln, items can have small firing lines or develop crazing over time, which should not be seen as damage but as an imperfection of the maker's recipes, probably unknown at the time of making. Items have often been used for many years and can have normal signs of wear, and gilt can have signs of slight disintegration even if never handled. I will reflect any damage, repairs, obvious stress marks, crazing or heavy wear in the item description but some minor scratches, nicks, stains and gilt disintegration can be normal for vintage items and need to be taken into account.
 
There is widespread confusion on the internet about the difference between chips and nicks, or hairlines and cracks. I will reflect any damage as truthfully as I can, i.e. a nick is a tiny bit of damage smaller than 1mm and a chip is something you can easily see with the eye; a glazing line is a break in the glazing only; hairline is extremely tight and/or superficial and not picked up by the finger; and a crack is obvious both to the eye and the finger. Etcetera - I try to be as accurate as I can and please feel free to ask questions or request more detailed pictures!
 
DIMENSIONS 12.5cm (5") tall; 14cm (5.5") between handle and spout and 10cm (4") diameter of body.