EXPEDITIONS. 



293 



are fitted, the mortar and machinery (weighing 

 altogether over tea tons) may be raised, and the 

 weight transferred by the same movement to 

 a great number of metallic rollers attached to a 

 framework of immense strength under the plat- 

 form. Then, by means of tackle, already ar- 

 ranged, the whole mass may be moved to its 

 desired position, and instantly, by a reverse 

 movement, replaced on the bed. In the centre 

 of the platform, and extending into the solid 

 mass beneath, is an iron cylinder or spindle 

 which prevents any side movement. 



The mortar carriage is constructed almost 

 exclusively of wrought iron. Its length is 

 about nine feet, and its height and width each 

 four feet. In form it bears the slightest pos- 

 sible resemblance to a land carriage gradually 

 sloping at the point where the mortar rests, 

 in the direction of the breech ; and having 

 wheels, yet not resting on them when the mor- 

 tar is discharged. The carriage is composed 

 principally of plate iron, riveted together, 

 braced and bolted. It is a framework of ex- 

 cellent design, and though weighing probably 

 not more than two tons, is capable of resisting 

 a pressure of one to two hundred tons. 



Two wheels are set close to the framework, 

 directly under the mortars ; and connected 

 with them are eccentric axles, so arranged as 

 to permit so large a part of the weight to be 

 thrown on the wheels, that the carriage may 

 be moved on them. 



It is not intended, however, that the recoil of 

 the mortar shall in any degree be taken up tfr les- 

 sened in its effect by the moving of the wheels. 

 The carriage lies firmly on the platform when the 

 mortar is discharged, and the only possible mo- 

 tion will be that of the vessel in the water. 



The bombs are the most formidable ordnance 

 lie known, except those used in the Kod- 

 columbiad of 15-inch bore. In addition to 



e two 32-pounder guns, the vessels are pro- 

 vided with pikes, cutlasses, and other necessary 

 weapons. 



The mortars cannot be fired directly over the 

 sides of the vessels, and therefore the latter 

 must be partially headed towards the point of 

 attack. The vessels will therefore be anchored, 

 and a part of the rigging removed. The extra- 

 ordinary weight and strength of the mortars, 

 the unprecedentedly large charge of powder, the 

 long range and high velocity of the projectiles, 

 with their destructive character, combine to 

 render this novel expedition one of the most 

 important undertaken during the war. The 

 vessels made their first rendezvous at Key 

 "West and subsequently proceeded to Ship 

 Island, Mississippi. 



6. The Mississippi Hirer Expedition. Soon 

 after taking command of the Western Depart- 

 ment, Maj.-Gen. Fremont became convinced of 

 the necessity of preparing a fleet of gunboats 

 and mortar-boats, for the purpose of command- 

 ing the Mississippi and other navigable waters 



of the "West, and decided upon the plans and 

 ordered the construction of the number of 

 each he deemed necessary. Their completion, 

 and the furnishing of them with their arma- 

 ment and crew, and the collection of the re- 

 quisite land force to accompany them, so de- 

 layed the expedition, that it did not move till. 

 February, 1862; but it was almost entirely 

 prepared during the year 1861. 



The fleet consisted of twelve gunboats, carry- 

 ing an armament in all of 126 guns, viz. : 



Benton 16 guns. 



Essex 9 



Mound City 13 



Cincinnati 13 



Louisville 13 



Carondelet 13 



St. Louis 13 



Cairo 13 



Pittsburgh 13 



Lexington... 9 



Conestoga 9 



Tyler. 9 



None of these guns are less than 32-pounders 

 some are 42-pounders, some 64-pounders, and 

 one (on the Essex) throws a shell weighing 128 

 Ibs. In addition to these, each boat carries a 

 Dahlgren rifled 12-pounder boat howitzer on the 

 upper deck. Several of the larger guns on each 

 boat are rifled. Naval officers regarded the 

 10-inch Dahlgren shell guns as their most effi- 

 cient weapons. The Benton carries two of 

 these guns in her forward battery ; the others 

 carry one each. 



Seven of the gunboats were iron-clad, and 

 able to resist all except the heaviest solid-shot. 

 These boats cost on an average $89,000 each. 

 The other five were of wood, but strongly and 

 substantially built ; all were fast sailers. 



Beside these, thirty-eight mortar-boats were 

 ordered ; each about sixty feet long and twenty- 

 five feet wide, surrounded on all sides by iron- 

 plate bulwarks, six or seven feet high. The 

 mortar itself weighs 17,200 Ibs. ; has a bore 

 easily admitting a 13-inch shell, and from the 

 edge of the bore to the outer rim is seventeen 

 inches. The mortar bed weighs 4,500 Ibs. 



The mortar-boats were thoroughly tested 

 before being used in actual service, and were 

 found to produce but slight recoil, and the con- 

 cussion caused by the iron bulwarks was reme- 

 died. With a charge of 11 Ibs. of powder the mor- 

 tars threw a shell, weighing 215 Ibs., a distance 

 of 2 miles ; and with a charge of 15 to 23 

 Ibs. the same shell was thrown from 3 to 3^ 

 miles. 



There was also a sufficient number of steam- 

 boats and tugs provided for towing and trans- 

 port service. The fleet was under the com- 

 mand of Flag-officer Andrew H. Foote, an ex- 

 perienced and able commander in the navy ; 

 and each boat was in charge of a lieutenant- 

 commanding, who had already seen service. 

 Very efficient service was subsequently per- 

 formed by this flet. 



