lot of four matching original and intact antique american industrial delco exide brand "power plant" battery cell jars designed and fabricated by or for the electric storage battery co., philadelphia, pa. nearly 20 matching "aqua-blue" glass jars are available, with the majority containing embossed acid-proof spill covers or caps. the blue-green glass varies from one jar to the next. the highly desirable color was likely caused by iron impurities in the sand used to fabricate the glass. the battery jars are free from breaks or cracks. embossed manufacturer markings are found on all of the jars. the glass imperfections or irregularities in the form of ripples, seeds, twists and varying lines provide added visual character. unusually thin in shape, with double-sided "nubs" and rounded bottom. the jars are freestanding. to meet the demand for electrical power in places where large utility companies had yet to extend power lines, small but complete generating plants consisting of an electrical generator, an engine (to drive the generator) and a storage battery to supply power (when the generator is not running) were a very popular and economical alternative offered by several manufacturers. the complete plants were known as "house lighting," "farm lighting," or "isolated" plants. unlike automobile batteries, farm lighting batteries, were not limited to the space they occupy, were not subjected to irregular charging and discharging, did not need leak proof covers and are were called upon to delivery very heavy currents for short periods. these facts were taken advantage of by the manufacturers, who designed their farm lighting batteries to give a much longer life than is possible in the automobile battery. both glass and rubber were used for farm lighting battery jars, and they may or may not have sealed-in covers. unsealed glass jars, such as the exide type, generally have a plate of glass placed across the top to catch acid spray when the cell is gassing. each jar with its plates and electrolyte formed a complete and separate unit which was easily disconnected from the other cells of the battery by removing the bolts that joined them. in working on a farm lighting battery, the repairman typically worked with individual cells instead of the battery as a whole - as is done with automobile batteries. exide was founded by w.w. gibbs in 1888 and was then called electric storage battery company. gibbs purchased the ideas and patents of inventor clement payen to make the storage battery a commercial product. gibbs targeted electric lighting companies so they could use the storage batteries to provide services to their customers. in 1900, the company developed a product of greater capacity and less weight for electric taxicabs. this battery was the first to bear the name exide, short for "excellent oxide." when the united states entered world war i, exide batteries were used to operate airplane radio sets and power radio stations. in 1938, exide acquired giant storage battery company, and expanded into battery chargers and testers. during world war ii, exide was a major supplier of batteries for u.s. navy submarines and primary contractor for batteries used in the mark 18 electric torpedo. exide entered the dry-cell battery industry in 1957 when it acquired the ray-o-vac company, then the second largest producer of dry-cell batteries in the us. following the acquisition of the wisconsin battery company, exide started producing motorcycle and specialty batteries. in 1987, it acquired general battery corporation. each individual piece measures at 6 1/4 inches x 2 1/4 inches x 12 1/2 inches.