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Part of the reason for that is there is no reference surface on the base to support good filament location.The single contact minature flange base used the flange surface as the refeence plane for locating the filament and so allows flashlight reflectors to be designed that have the filament at focus without any adjustments.The Leclanche type dry cells used have a nominal voltage when fresh of 1.5 volts so two in series would be 3.0 volts.The end of life voltage is taken as 0.9 or 1.0 so two in series would be 1.8 or 2.0 volts. The 1915 patent 1163887 (see below) by Charles Burgess mentiones this and his lantern has a two position switch so that a resistor can be inserted for the first few hours of operation and then the direct connection made for the remainder of the battery life.The 222 minature screw base Lamp has a built in lens and so does not need to be in a flanged base.There seems to be a disconect between the battery makers and the lamp makers.When it's on and you are looking at a side view like this there is not much light coming out, almost all the light is aimed in the narrow beam like for the 222. Q quick check of three os the flattened bulb type lamps showed they all had this type of "S" filament.
Military Survival Lights web page M-227 Signal Lamp Background Components Lamps Lamp Test E10 Repairing Loose Bulbs Photos at 2X life size 1915 Catalog listing of Lamps Table of Newer Lamps Edison 10 mm Miniature Screw Lamp Base (E10) Batteries Cylindrical Prismatic Size Table No. 1653 Electric Candle Table Lights Electric Storage Battery Co. Once the dry cell battery became available flashlights became more popular than they were when a lead acid or other wet battery was needed.GE 223 Lamp is rated for 5 hours at 2.25 Volts @ 0.25 Amps.After measuring the I-V curve from 0 to 215 ma and ploting in Excel shows the first few points coming up from zero to be off the straight line you get afterwards, so eliminating them and plotting from 125 to 215 ma gives this straight line: I(ma) = 67.259*V 104.9 with a fit of R2 = 0.9982 solving for 2.25 volts gives I(ma) = 256 ma, matching the published data pretty well.I have included on this page what most people would consider a flashlight, but also any light that uses the No. Also some fixed battery powered lights like used on barricades or in purses, &etc. And some closley related patents like anti reflection coatings or earlier lights.