OLD TOWN – Jim Page places a large, square, aerial photo, taken in 1956, on the table. The image looks like an island afloat in a sea of wood chips.

“Close,” said Page, when I hazarded a guess. “That’s pulpwood in a lake.”

Why would a black-and-white aerial photo of an island in a lake full of pulpwood be of any use to anyone?

“If you know how many cords to the acre, by using this photo you can calculate how many cords there are in the lake, which is a way to inventory a company’s natural resources,” said Page, chief executive officer for James W. Sewall Co.

That kind of data is one small example of the complex information aerial photography can yield.

The history of its past and the course of its future are embodied in the mapping services James W. Sewall Co., established in 1880, performs for clients in the forest industry, for utilities companies and for municipalities around the globe.

Among the company’s areas of expertise are engineering, boundary surveying and topographic mapping, water supply and distribution services, municipality tax maps, “cover-type” mapping to classify and inventory natural resources, and land ownership and mill location maps.

“The art, the aesthetics of mapmaking is essentially gone,” Page said. Computers and digital imaging have replaced the old way of drafting maps by hand with pen and ink on paper or linen – like the copy of a 1788 plan of parcels to the east of the Penobscot River.

Names on a portion of the map match up with the 1790 census for Eastern River Township No. 2 – John and Samuel Crage Jr., Thomas and John Partridge, John Hancock, Calvin Turner, Samuel Soper, Joseph Viles.

Water bodies visible on the map include the Orland River, which runs into the eastern channel of the Penobscot; and Alamoosook Lake. The area shown was incorporated as Orland in 1800.

The company’s antique maps, housed in a small, cool room in the basement of Sewall headquarters on Center Street, also include, said analyst Peralee Burbank, “original plan maps of the Old Town area dating from the 1880s, true copies of maps filed in the Boston Registry of Deeds before Maine achieved statehood in 1820, and the original lotting maps of Indian Island.”

“The Indian Island maps are the only copies in existence,” said Lisa Schoonmaker, communications director.

Surveyors on the ground used a surveying chain, consisting of rods and links, to collect data for the oldest maps in the Sewall archives. One map, dated 1868, shows that what we know as Route 9 from Bangor to Calais was even then- well before airplanes – known as the Airline Road.

“‘Airline’ means the shortest distance between two geographic points and has nothing to do with airplanes or flight,” Schoonmaker said.

An undated map of Marsh Island shows a parcel labeled “Molly Molasses,” and several other parcels bear her sons’ names. Molasses – although perhaps not the same one indicated on the maps – is mentioned in Henry Thoreau’s “The Maine Woods,” a subject of Bangor Public Library’s recent Bangor Reads! lecture series. James W. Sewall Co. forester Mary MacDonald presented a program about maps and mapmaking in that series.

“Maps convey a great deal of information in a rapid, efficient way,” Page said. “The old maps were not as accurate, but they met the requirements of the times.”

Today’s maps are so highly sophisticated and detailed, they show the centerlines of roads, the types of trees on forestland or streets, the volume of piles of wood chips or the distance between bolts on a bridge.

In addition, maps can show locations of water supplies, evacuation routes and other data crucial to the protection of people, property and infrastructure in the event of a crisis. Such data is useful in planning homeland security strategies, a subject that has gained prime importance since the Sept. 11, 2001, attacks on the Pentagon and the World Trade Center.

Schoonmaker pointed out that James W. Sewall Co.’s infrared aerial photography was used in New York state to control the spread of West Nile Virus.

“Areas that could not be identified easily by walking through an area, such as wetlands, swimming pools and catch basins, were located from the air and photographed. Using the photographs, experts identified mosquito breeding sites, which were sprayed with larvicide,” Schoonmaker said.

Recently, James W. Sewall Co. was nominated for a construction industry innovation award, one of 35 nominations worldwide. The company’s innovation was the use of digital close-range photogrammetry – a technology that measures objects using multiple close-range photographs – for the structural measurement and analysis of the half-mile-long Waldo-Hancock Bridge now undergoing renovation.

Surveyors collected the data in one day, making flight passes by helicopter over the bridge. This technique also has been used in planning the preservation of historic structures.

The company also is conducting a tax-mapping project in Puerto Rico, Page said.

“It’s the first survey that has been done there since the 1930s,” Page said.

Recently, James W. Sewall Co. acquired Weiler Mapping Inc. of Horseheads, N.Y., Page said. Weiler Mapping will retain its company name and roster of employees.

The James W. Sewall Co. has offices in Old Town; Louisville, Ky.; and Charlotte, N.C. For information, visit the Web at www.jws.com, or call 827-4456.