Scientific Lectures. 183 



remarkable features of the siege. They were addressed to raw vol- 

 unteer infantry, absolutely ignorant of artillery practice until the 

 siege commenced, and taught what little they knew about serving 

 the guns in the intervals of leisure from dragging them over the beach 

 into battery," cfec, &c. A modest pamphlet of forty pages was pub- 

 lisked at the end of the war. It is the Keport on Military Eailways. 

 By a summary of their operations it appears that at one time there 

 was a force of 24,964 men employed, 2,105 miles of railway were 

 operated with 419 locomotives and 6,330 cars, and there was built 

 and rebuilt 641 miles of railway, including twenty-six miles of bridges, 

 and the whole expenditure of the department, after deducting 

 the materials sold at the conclusion of the war, was a little under 

 130,000,000. When Gen. Grant advanced from Washington, on his 

 final campaign, the Rappahannock bridge, 625 feet long and thirty- 

 five feet high was rebuilt in forty hours, and the Potomac bridge, 

 near Acquia creek, 414 feet long, and eighty-two feet high, was built 

 in the same number of hours. Fourteen miles of the railway was 

 rebuilt in eight days, and was used for only one week, to convey 8,000 

 wounded men from the battle fields of the Wilderness and Chancellors- 

 ville. On the evacuation of Richmond by Gen. Lee, the railway was 

 relaid, and put in operation as fast as the troops marched. The order 

 was that the raihvay must be completed to headquarters every night. 

 Frequently the construction corps advanced with a completed rail- 

 way, faster than those who were employed in laying down the tele- 

 graph lines. At the West, on General Sherman's march from 

 Chattanooga to Atlanta, in May, 1864, the railway was constructed 

 and "kept pace with the army." The Chattahoochie bridge, 780 

 feet long, and ninety-two feet high, was built in four and a half days. 

 In October of that year the rebel General Hood passed around Sher- 

 man's army, and destroyed thirty -five and a half miles of the railway, 

 and 455 feet of bridging. In thirteen days after he had left the line 

 was restored, and the trains run regularly. In one case, twenty-five 

 miles of track and 230 feet of bridging in one stretch, at Tunnel 

 Hill, were reconstructed in seven and a half days. In February, 

 1865, General Forrest destroyed a long line of this railway, and in 

 thirty days it was reconstructed, including 2,200 feet of bridging. 

 General McCallum says : " Had any failure taken place, either in 

 keeping these lines in repair, or in operating them, General Sher- 

 ' man's campaign, instead of proving, as it did, a great success, would 

 have resulted in disaster and defeat." General Galium told me that 



