WHEN a person is desirous of procuring a published work upon any subject, it is natural for him to inquire for the sources of information from which the author has compiled that work. I have, therefore, without wishing to be considered egotistical, concluded to issue this prospectus to such as have an interest in the Battle of Gettysburg, that they may know what I have already done, and what I yet propose to do, to eliminate the history of that battle.

ISOMETRICAL DRAWING OF THE GETTYSBURG BATTLE-FIELD.

In compiling the Isometrical Drawing of the Gettysburg Battle-field, it was first necessary to establish its extent and boundaries. When I arrived at Gettysburg the debris of that great battle lay scattered for miles around. Fresh mounds of earth marked the resting-place of the fallen thousands, and many of the dead lay yet unburied. It therefore required no guide to point out the locality where the battle had been fought.

As the term field, when applied to a battle, is generally used figuratively, and, by the general reader, might be misunderstood, it is well to consider at the start, that the battle-field of Gettysburg not only embraces within its boundaries many fields, but forests as well, and even the town of Gettysburg itself is included in that battle-field. The formation of the ground and the positions of the troops, favored the plan of sketching the field while facing the west. Consequently the top of my DRAWING of it is west; the right hand, north; the left, south, &c. There was no point from which the whole field could be sketched, nor would such a position have favored this branch of Art. On the contrary, it was necessary to sketch from every part of the field, combining the whole into one grand view.

Having located its boundaries, I commenced at the southeast corner, and gradually moving toward the north, I looked toward the west, and sketched it carefully, as far as the vision extended, including fields, forests, houses, barns, hills, and valleys; and every object, however minute, which would influence the result of a battle. Thus I continued to the northeast boundary, a distance of five and a half miles. The next day I resumed my work at the south (having advanced to the point where my vision had been obstructed the preceding day), and sketched another breadth to the north, as before; and so continued, day by day, until I had carried my Drawing forward four and a half miles, which included within its limits the town of Gettysburg. When the Battle-field had been Isometrically drawn, I sketched in the distance and added a sky.

This Drawing was the result of eighty-four days spent on that field immediately after the battle, during which time I sketched accurately the twenty-five square miles which it represents.

I spent two months in hospital writing down the statements of Confederate prisoners, and as they became convalescent, I went over the field with many of their officers, who located their positions and explained the movements of their commands during the battle.

I then visited the ARMY OF THE POTOMAC, consulted with its Commander-inChief, Corps, Division, and Brigade commanders, and visited every Regiment and Battery engaged, to whose officers the sketch of the field was submitted, and they, after careful consultation, located upon it the positions of their respective commands.

From the information thus obtained, I have traced the movements of every Regiment and Battery from the commencement to the close of the battle, and have located on the Drawing its most important position for each of the three days.

Since its publication I issued an invitation to the officers of the Army of the Potomac to visit Gettysburg with me, and point out their respective positions and movements, thus giving an opportunity to the actors in this great drama to correct any misapprehension, and establish, while still fresh in memory, the facts and details of this most important battle of the age. This invitation was responded to by over one thousand officers engaged in the battle; twenty-eight of whom were Generals commanding. And it may be interesting to those who possess the Drawing, to know that but one solitary Regiment was discovered to be out of position on it.

Many thousand copies of this work have been sold, yet the demand still con