Patent Office Registration Marks And Numbers.
Diamond shaped pottery marks, printed or impressed on the base, are official marks of the Patent Office Registry of Designs, set up in 1842 to protect manufacturers from plagiarism and piracy.
In 1868 the positions of the code letters and numbers were changed, but the registration mark continued until December 1883, when it was replaced by a serial number. (see Pottery Marks )
Registration of a design gave three years protection, during which time there could be continuous or sporadic production of the design or pattern.
Patent Office Pottery Marks
Left registration mark : 1842 – 1867 Right registration mark : 1868 – 1883
a – catagory iv – ceramics
b – year
c – month
d – day
e – batch number
Pottery Marks – Date Letters
1842 – X 1843 – H 1844 – C
1845 – A 1846 – I 1847 – F
1848 – U 1849 – S 1850 – V
1851 – P 1852 – D 1853 – Y
1854 – J 1855 – E 1856 – L
1857 – K 1858 – B 1859 – M
1860 – Z 1861 – R 1862 – O
1863 – G 1864 – N 1865 – W
1866 – Q 1867 – T 1868 – X
1869 – H 1870 – Q 1871 – A
1872 – I 1873 – F 1874 – U
1875 – S 1876 – V 1877 – P
1878 – D 1879 – Y 1880 – J
1881 – E 1882 – L 1883 – K
Patent Office Pottery Marks
January – C February – G March – W April – H May – E June – M
July – I August – R September – D October – B November – K December – A
As we can see the pottery mark on the left would read like this (as it only goes up to 1867) :
a – ceramics b – 1851 c – December d – 15th e – batch number 8
The pottery mark on the right (1868 onwards) :
a – ceramics b – 1875 c – May d – 23rd e – batch number 7
A bit tricky to get the hang of but with a bit of practice you will be reading pottery marks like an expert.