Ink bottles..I had 2 choices...the pic where you see the label but not the color or the one where you see the color but not the label..."special recorder /INK /BAILEY- meter" Purple,Green,Cobalt blue and the big bottle :Phtalein red (for test purpose only)
Dr Bailey (engineer) was born in 1880..he worked as a tester in many coal plants. In 1909 he entered a partnership doing combustion and efficiency tests throughout Us.In 1916 he founded his company thanks to his invention,the Bailey boiler meter,for fuel testing.He improved so much the efficiency of the boilers that,in WWII,he helped eliminate the boiler smoke,making the ships less visible to enemy planes and submarines...He launched a branch in Canada,BaileyMeterCo Ltd of Canada in 1921...He has been honoured with many titles..among them Honorary member of Institution of Mechanical engineers in England (Very rare for an american).....As for the ink and how it's applied in testing it's a big mistery..for now..keep on searching...