nent at present are the projectiles of the Messrs. Hotchkiss, of Conn., of Mr. Silvanus Sawyer, of Fitchburg, Mass., of Mr. Schenkl, of Boston, and of Hon. C. T. James, of Providence, R. I. The Hotchkiss projectile is composed of 3 distinct parts, a cast-iron conical head and base, which are tied together by a ring or zone of lead which forms the middle portion, and extends quite through in a sheet of lead between the two end pieces. The effect of the explosion is to crowd the base forward and cause the lead to bulge out round the middle and fill the grooves. This it does very efficiently, and the projectiles, when recovered, are generally found complete with the lead ridged to the full depth and width of the grooves. Sometimes, however, the pieces of the projectile have been torn apart by the explosion. The Sawyer projectile is a cylindroconoidal shell of cast iron, with a brass cap screwed into the truncated apex of the cone. By this opening the powder is introduced, of which a 12-pounder shell holds 14 oz. Under the brass cap is the percussion powder. The outer surface of the projectile is first tinned over to cause adhesion of the coating of lead, which is next run on to the cylindrical part in a coating, nearly of an inch thick, with 6 ridges upon its surface, adapted to the grooves of the bore of the gun with its same twist. The Schenkl projectile, which is much used by the troops from Mass., is a cast-iron bullet, the greatest diameter of which is about the length from the front end. The posterior portion tapers off, terminating in a truncated apex, and is ridged longitudinally. To bring it up to cylindrical shape, a covering of papier mache is filled in between the ridges and around the cone. The effect of the explosion is to drive this forward and into the grooves of the barrel; and if it should be thrown off soon after it leaves the gun, it does no harm. James' projectile is a cast-iron cylindrical bullet with a conical head, which may be solid, or for use as a shell, hollow. The cylindrical body, with the exception of a narrow band next the cone and another at the rear end, is of an inch, and the bands of an inch less than the diameter of the bore, (in the case of a 42-pounder;) and from the depressed portion 10 rectangular openings, like the mortices in the hub of a wheel, connect with a central cavity extending in from the rear end. A cylinder of sheet tin is laid round the central portion, and over the tin and around its edges is laid a wrapping of canvas saturated with tallow, and firmly secured by sewing, making the whole diameter equal to that of the bore of the gun; but there remains an open annular space between the tin and the cast-iron cone, which is filled with melted lead, poured in through the central cavity. This adheres to the tin and forms a compact band around the central portion of the projectile. In the discharge the gases rush into the central cavity and press out this band, forcing the canvas into the grooves, thus preventing the escape of any portion of the gases past the bullet. In practice, the lead band sometimes separates from the iron projectile soon after leaving the gun, seriously disturbing the accuracy and efficiency of the shot; but in general it remains on, and takes such hold of the grooves as to cause the projectile to assume the spinning motion. Gunpowder.-The gunpowder for the military service is made by private contractors, in mills in various parts of the country. The same proportions of ingredients are used for the several kinds designated musket, mortar, cannon, and mammoth, which differ from each other only in the size of the grain. The proprotions of saltpetre are 75 to 76, of charcoal, 14 to 15, and of sulphur 10. The size of the grain is fixed by sieves, the musket powder being 1,100 particles in ten grains Troy weight, and the cannon powder 150 particles. It is packed in barrels of white oak with cedar hoops. Powder barrels made of strong sheetiron, corrugated with heads formed by turning over the metal, have been made, and are now on trial. The mammoth powder is of coarsest grains, such as pass through a sieve with inch holes, but not through one of inch holes. Capt. Rodman, of the Ordnance Department, has recently invented a new powder, which is found very serviceable. The design of it is to produce the combustion increasing in intensity instead of diminishing from the first ignition, as is the case with ordinary gunpowder. This he effects by making cakes of dust powder, and perforating them with numerous small holes with wires. The ignition spreading through these holes occupies a sensible time, and spreads over an increasing surface of combustion. The effect of this is to exert the strongest impulse upon the projectile after it has once started from its seat and its inertia is overcome. The large-grained powder produces a similar effect. Gun-cotton, though having an explosive force, compared to gunpowder, as 8 to 3, is not approved of for military service for various reasons: as, the danger of preparing and keeping it in large quantities, its too violent action, its changeable character, &c. Tents. The military campaigns of 1861 have brought about important changes in the construction of tents for soldiers. Those previously in common use were altogether deficient in proper arrangements for warming and ventilation. They were made of a light sheet of duck, laid over a ridge-pole, which was supported upon two upright poles set in the ground about 6 feet apart. It was pinned down to the ground when stretched out to sufficient width; and the ends were closed by triangular pieces, which were drawn together and tied. Sometimes one end was made entirely close, while the other was furnished with the overlapping flaps, which could be opened or closed as desired. Such were the tents almost universally used by the French in the Crimean war, and called by them tentes d'abri, simplified by the use of a rope instead of the ridge-pole. They were also made for convenience of transportation, in pieces that buttoned upon each other. When made close, for the sake of warmth in cold weather, these tents soon became filled with impure air, which proved very injurious to the health of those who lived and slept in them. A much better form was obtained from the Comanche lodge, the common tenement of the Indian tribes of the prairies, and of the traders, trappers, and hunters of the far West. These are conical-shaped tents, with hides or cloth laid upon long poles, set around a circle upon the ground, and meeting at a point over the centre, where they are secured together. The apex is left open, and a triangular wing is arranged, so as to take the wind in such manner as to produce an upward draught, thus admitting of the use of a fire in the tent, and securing without it a free circulation of air. The tent introduced by Major H. H. Sibley, and generally known in the army as the "Sibley tent," is the Comanche lodge, with an upright central standard set into an iron tripod, which takes the place of the poles and can be easily transported. This has been used with great satisfaction in exposed encampments, and in severe weather it is made more comfortable by a basement excavated in the ground to the depth of 3 or 4 feet. In the latest improved tents this form is still chiefly preserved, and the principal improvement is in the use of an iron pipe, 3 or 4 inches in diameter, for the central upright, which serves as a smoke-pipe for a small sheet-iron stove. India-rubber cloth tents, on a plan invented by Mr. John Rider, and termed "tent knapsacks," are also much used. They are formed of separate pieces of the stuff, each 5 feet 3 inches long, and 3 feet 8 inches wide, made to button snugly together to form a tent, and when taken apart each piece makes a tight covering, in which to carry blankets, overcoats, clothes, &c., instead of in a knapsack. The pieces being all alike, any four men carry with them sufficient to form a cover that will shelter 5 to 7 men. Extra pieces are used with great advantage to spread on the ground as a protection against dampness. Various other tents, specially adapted to secure warmth and ventilation, are in use by the American army, and in general they are far superior to those of any other nation. The sudden and large increase of the army made some modification of the system of organization connected with the supervision of the hygiene and comfort of the troops necessary. A commission of inquiry and advice was accordingly instituted, with the object of acting in cooperation with the Medical Bureau. This commission was appointed on the 9th of June, by the Secretary of War. The following persons accepted the duty assigned to them, viz. Henry W. Bellows, D. D., New York; Prof. A. D. Bache, Washington; Elisha Harris, M. D., New York; George W. Cullum, Alex ander E. Shiras, Robert C. Wood, M. D., U. S A., Washington; William H. Van Buren, M. D., New York; Wolcott Gibbs, M. D., New York; Samuel G. Howe, M. D., Boston; Cornelius R. Agnew, M. D., New York; J. S. Newberry, M. D., Cleveland. To these were added by the commission itself others, to wit: George T. Strong, New York; Horace Binney, jr., Philadelphia; Thos. M. Clark, D. D., Providence, R. I.; Joseph Holt, Kentucky; R. W. Burnett, Cincinnati; Mark Skinner, Chicago; Frederick Law Olmsted, New York. The order appointing the committee, vested in them no power beyond that of "inquiry and advice in respect of the sanitary interests of the United States forces." It was directed, especially, to inquire into the principles and practices connected with the inspection of recruits and enlisted men; the sanitary condition of the volunteers; to the means of preserving and restoring the health and of securing the general comfort and efficiency of troops; to the proper provision of cooks, nurses, and hospitals, and to other subjects of like nature. The office of the commission was thus purely auxiliary and advisory, created solely to give voluntary aid to the Department and Medical Bureau, in meeting the pressure of a great and unexpected demand on their resources. The services of competent physicians were secured, and sent into the field, each having a defined portion of the army under his observation. Among the subjects to which their attention was especially directed, and on which they were required to make detailed written reports, were: the quality of rations and of water, the method of camp cooking, the ventilation of tents and quarters, the drainage of the camp, the healthfulness of its site, the administration of the hospital and the sufficiency of its supplies, the police of the camp, the quality of the tents and of the clothing of the men, the material used for tent flooring, if any, &c., &c. Whatever deficiencies or evils they found to exist by which the health, morale, or efficiency of the men might be endangered, they were instructed to indicate to the proper officer, at the same time offering advice, if it was needed, as to the best method of remedying them. The results of their investigation, only for the half year since their appointments, have secured some valuable information, and increased the comfort and health of a portion of the ariny. After the inspection of each camp or post, the inspector was required to make an elabo rate report upon its condition. More than four hundred of these reports were received and compared, and digests prepared. The inspec tions made in the months of September and October, furnish the principal basis of the conclusions of the commission. Their statistics have been derived from more than two hundred regimental returns, of which thirty-seven were from regiments recruited in New England; one hundred and one from regiments re craited in the Middle States, including Virginia, Maryland, and Delaware; sixty-two were from regiments recruited in the Western States, including Kentucky, Missouri, Kansas, and Nebraska. The time occupied in recruiting each of these regiments, averaged six weeks; the shortest period being ten days, the longest about three months. In seventy-six and a half per cent. of the regiments inspected, native Americans were found to constitute the majority. In six and a half per cent. there was a majority of Germans; in five and a half, of Irish; and in five and a half the number of native born and foreign born was about equal. Of one per cent. the returns give no information on this point. It is considered as near the truth to state that about two-thirds of the volunteer soldiers are American born, and nine-tenths citizens, educated under the laws of the Union and in the English tongue. Sufficient investigation has not been made to determine this statement with complete accuracy. From incomplete returns, the average age of the volunteers is judged to be a little below twenty-five years. Somewhat more than onehalf of their number are under twenty-three. The average age of the officers is about thirtyfour. The number of men of any age between eighteen and forty is not far from double the number of those five years older. For example, the number of those twenty years old is double the number of those at twenty-five. It is important that the degree of liability to death from disease in war, at different ages, should be ascertained. Data are accumulating which will serve to determine this. It is still more important to determine the degree of liability to sickness at different ages in army life, especially as this affects the question of the relative efficiency of men, as soldiers, at different ages. For this purpose, no sufficient records are at present made by the surgeons of the army, and it was not practicable for the commission to supply the deficiency. In fifty-eight per cent. of the regiments, there had been no pretence of a thorough inspection of recruits on enlistment. In only nine per cent. had there been a thorough re-inspection when or after they were mustered in. In the month of October, 1,620 men were discharged from the army of the Potomac, as unfit for service, of whom three-fifths were thus discharged on account of disabilities that existed at and before enlistment, and which an intelligent surgeon should have discovered on their inspection. Camp sites have been generally selected for military reasons alone, and with little if any regard to sanitary considerations. The regimental surgeon has seldom been consulted on the subject. In many instances, disease was directly traceable to this omission. One-fourth the regiments were found encamped on sites which had previously been occupied by others. Except at Cairo and in the prairie region, camps have been generally formed on the tops and sides of hills. During the hot weather nearly one-half were in the shade of woodsan objectionable circumstance. Water of wholesome quality was found within convenient distance of the camp in all but two cases. The regiments encamped at Cairo were abundantly supplied with ice during the hot weather. The average occupation of a camp site, up to the date of inspection, had been twenty-one days. In the east this period had generally been largely exceeded, and regiments frequently occupied the same ground much longer than was safe or advisable. In those cases where the drainage by inclination was the most difficult, the soil and subsoil have been porous and favorable to drainage by filtration. As the immediate inconvenience occasioned by a shower of rain in these flat sites led to the practice of better judgment in artificial drainage than has generally obtained on the hill sites, there has been less prejudice to health from poor drainage in the fixed camps at the west than in those of the armies of the Potomac and Western Virginia, which have generally been upon clay soils or over retentive subsoils. There has been, for instance, not half as much rheumatism at Cairo as in the eastern camps and those of West Virginia. Until recently, the artificial drainage of camps, when first visited by the inspectors, was found very imperfect-the men of each tent being left in most cases to form drains around it according to their own judgment. In consequence of their ignorance, unskilfulness, or indolence, the drains were often useless, and not unfrequently aggravated the evil they were designed to remedy. As soon, however, as good examples became frequent, the practice of a systematic arrangement began to be generally adopted. The majority of volunteer camps are now at least as well drained as those of the regulars. The average depth of the camp drains is about six inches. In about one-half the camps the drains were found more or less clogged, owing to their crookedness and imperfect construction, and to want of proper attention in keeping them clean. The consequence of neglecting drainage was frequently apparent on inspection of the sick list. In general, the plan for laying out a camp supplied in the Army Regulations, has been approximately followed; but the tents are placed more closely together than the minimum there prescribed. The difficulty of drainage is thus increased, and the narrow spaces between the tents, difficult to be swept, become half-concealed receptacles for rubbish. Six men are usually provided with lodging in one of the wedge tents. In the Sibley tent from twelve to sixteen; of late sometimes twenty. 66 Tents are seldom tolerably ventilated at night. Of the regiments under consideration occupying the wedge tents, none were found in which the inspectors were satisfied that proper As the forces in Western Virginia were, si a rule, unprovided with rubber blankets, and as they have suffered special hardships in other respects, they are excluded from the comparison in the second column. attention was paid to ventilation, and it was obvious in some cases that the men suffered in health in consequence. The Sibley tent is more convenient for ventilation, and cannot as well be tightly closed as the wedge form. It is now found that typhus is occurring more A limited examination of the diseases of the frequently in the regiments occupying these army indicates that the largest proportion of tents than in those that have the Sibley-the those of typhoid type occur with regiments ratio being 29.5 to 23. The Massachusetts sleeping on rubber blankets, the least with Seventh Volunteers, Colonel Davis, Surgeon those on straw or boughs; the largest propor Holman, is the only volunteer regiment re- tion of catarrhal with regiments on wooden ported, in which a thorough ventilation of the floors, the least with those on the ground; the wedge tent had been generally established. It largest of rheumatism with those on wood, was here induced by the occurrence of typhoid the smallest with those on straw or boughs; fever, and by this, prominently among other the largest of malarial with those on the means employed for the same end, the unusual ground, the least with those on straw or result of banishing this formidable disease has boughs. been obtained. The inspectors have advised the striking of each tent once a week, for the purpose of giving it a perfect cleansing and airing. Fifty-eight per cent. of the regiments had been provided with the wedge tent, ten with the wall tent, seven with the bell tent, nineteen with the Sibley, others not stated. Ninety per cent. of these were made of good canvas; the remainder were of twilled cotton or drilling, or so old as to be leaky. Twenty-four per cent. of the regiments were provided with tent flooring of boards, twenty per cent. with india-rubber cloth; in twentyone per cent. straw or branches were used for this purpose, and in thirty-five per cent. the men slept on the ground. The following table shows the relative proportion of these several kinds of flooring in the three great divisions of the army. The important influence it will be doubtless found to exert on the health of the men, justifies especial inquiry into the subject: As had been presumed by the commission, it has been proved that the best bed for soldiers in camp can, with a little skill, be formed from fir or cedar spray, whenever it can be obtained in sufficient quantity. It should be frequently removed and burned, after a thorough cleansing of the tent floor, the tents being struck for the purpose. Experienced officers generally object to the board floors in tents. They are thought to be more damp than the ground itself, and they offer an opportunity for the collection of rubbish and dirt, and make them difficult of removal. Privies had been established in all the camps inspected, except those of two or three regiments recently mustered in. In eighty per cent. of the camps, they are reported to be properly arranged and kept in proper order, no offensive odor drifting from them. In twenty per cent, proper attention was not given to them, and the health of the men was more or less seriously endangered in consequence. In sixty-eight per cent. of the camps, the men seemed to be effectively restricted to the use of privies. In thirty-two per cent. the proper prohibition was found by the inspectors not to be strictly enforced. In seventy-seven per cent. of the volunteer camps, slops, refuse, and offal are systematically removed to a distance from camp by a daily detail of men. In twenty-three per cent. this duty was performed irregularly or very imperfectly. In nineteen of these twenty-three camps, the inspectors found odors of decay and putrefaction perceptible in and about the tents and streets. The shirts used by the men were found to be of poor quality, in twenty-six per cent. of the regiments examined. In seventy-four per cent. they were of the Regulation quality. In ninety-four per cent. the men had been provided with two shirts each. In four and a half per cent. they had but one each, and in the remainder only a part were supplied properly. Eighty-two per cent. of the regiments were well supplied with overcoats, and seven per sent. partly so. In eleven per cent. there were none at the time of the inspection. In only three per cent. of the regiments were the overcoats of poor quality. Seventy-five per cent. of the regiments were provided with good cloth body coats; the remainder with flannel sack coats or cloth jackets. Of two hundred regiments, all were provided with pantaloons-one hundred and seventy-five sufficiently, eight indifferently, seventeen very poorly. Men have been frequently seen during the summer on duty and on parade in their drawers alone. In seventy-five per cent. of the regiments, one good blanket had been issued to each soldier. In twenty per cent. two had been provided; these being, however, in most cases, of inferior quality. In five per cent. the men had never all received each a blanket. In the army of the Potomac the average constant number of sick, per one thousand men, has been sixty-three; in the department of Western Virginia, one hundred and sixty-two; in the Valley of the Mississippi, one hundred and sixteen. The average constant number of sick during the months of August, September, and October, in the regiments east and west, so far as visited, has been seventy-seven per thousand. In this number all relieved from duty, from any sort of physical indisposition, however slight, are included. The average number of men constantly sick in the regiments, from several of the States respectively, is nearly as follows: New York, (per thousand strong). Pennsylvania, 66 Massachusetts, Connecticut, Vermont, Island being probably the most fortunate in this respect, which fact, however, is chiefly due to their superior discipline early in the campaign. It is difficult to compare the rate of sickness of foreign armies with that of the volunteers, because it is uncertain what degree of sickness in them places a man upon the sick list. Our volunteer surgeons are, undoubtedly, very accommodating in this respect, probably more so than the surgeons of the regular army or of foreign armies. It has happened in more than one instance that upon an order to advance against the enemy being given, every man of a regiment then on the sick list immediately reported himself well, was discharged, and shouldered his musket in the line of battle. It is probable that at least one-half those returned as sick by the surgeons of volunteers would do the same, under similar circumstances; that proportion being excused from duty on account of a cold in the head, severe fatigue, or a slight indigestion. In the whole British army, in time of peace, 6.5 per cent. of the force otherwise available, is reported constantly "in hospital." Of the British army in the Peninsula under the Duke of Wellington, 1808-1814, twenty-one per cent. (or 9,300 of an average force of 44,500 men) was constantly "sick in hospital." The number of sick ranged from nine to thirty-three per cent. of the whole force at different periods. These rates were exceeded in the British army of the Crimea. To maintain 100 effective soldiers in the field, it there became necessary to provide for 26.6 sick men. The annual rate of mortality was three per cent. by 52 wounds, and twenty per cent. by disease. 55 57 49 88 124 The annual rate of mortality in the British army, at home and in time of peace, was from one and a tenth to two per cent. in ten years 76 preceding 1847. 36 156 .192 42 The average mortality of the army of the 76 Potomac has been, during the summer, at the rate of three and a half per cent., (allowance being made for those who die after their discharge, from causes connected with army life.) Imperfect data received from the West, indicate a considerably larger rate for the whole army; probably it will not be far from five per cent. if sweeping epidemics should be escaped. The forces from Ohio and some other States have been, to a considerable extent, subject to unusual privations and exposure, during the campaign among the mountains of Western Virginia. A similar remark applies to those of Illinois, in Missouri. There is reason to think that the most sickness has occurred where regiments, raised in far northern and highland districts, have been removed to lowland, fluvial, and seaboard districts; those, for instance, from Maine and Vermont, the ridge counties of New York, and from Minnesota, being more subject to distinct disease, as well as to demoralization, or ill-defined nostalgia, than others in the army of the Potomac. The healthiest regiments, physically and morally, have been those from the seaboards, as of New Hampshire, Massachusetts, Rhode Island, Connecticut, and New Jersey; those from Rhode The following is a statistical classification of the diseases and casualties of forty-seven regiments of volunteers and two of regulars, during periods averaging forty days for each regiment, between July 1st and October 1st, 1861. The classification adopted is that used in the British army, and for civil registration in England, Australia, and several of the States of the Union. The data are taken from the consolidated returns of the regimental surgeons to the medical directors of the military departments of the Potomac and of the West: |