Rev. H. G. Buehler, head-master of Hotchkiss School, delivered a lecture in the Union last evening on "The Battle of Gettysburg" before a large audience. The stereopticon views illustrating the lecture consisted of charts showing the positions of the divisions of each army before the battle and during its various stages; pictures of the battlefield as it appears at the present day and of the monuments erected to the soldiers; and many contemporary paintings, photographs and wood-cuts portraying the struggle.

In proportion to the numbers engaged, said Mr. Buehler, the losses at Gettysburg were the greatest of the war. In one regiment alone the losses were 83 per cent, as compared to 33 per cent in the charge at Balaklava. A Confederate battalion was obliged to count its standards in order to realize that at one time it comprised ten regiments, and during Pickett's charge a body of cavalry lost 27 out of 36 of its horses within ten minutes.

Taking up the story of Gettysburg at the time when General Lee decided to strike a crushing blow in the North, Mr. Buehler followed the two armies in their reconnoiters around the Federal capital, showed the strategic position which the armies occupied on each the three days of the battle, and then described the battle and General Lee's retreat. He explained the decisive character of the conflict by referring to the session of the English House of Commons on the eve of the battle, when, after an argument extending far into the night, it was decided to wait before formally recognizing the Confederate government.

Mr. Buehler graphically described the terrific charge of the Second Massachusetts Regulars, who rode to certain death without a word of protest. In this regiment 13 of the 16 officers killed during the war were Harvard men; their names are inscribed in the transept of Memorial Hall.