lieutenant-colonel and brevet colonel in 1915, and advanced to the rank of major-general at the beginning of 1917. On the formation of the Air Ministry at the end of that year he was brought home to become chief of the staff, but he resigned the position in the following April; he was however a few weeks later given command of the " Independent Force," which carried out extensive raids into German territory during the closing months of the struggle. He had been made a K.C.B. in 1918, and on the final distribution of honours for the war he was given a baronetcy and received a grant of 10,000. He was gazetted air vice-marshal on the introduction of the new designations of rank in the air service, and in 1919 he was pro- moted air marshal and became chief of the air staff.
TRENCH FEVER. Early during the World War, in 1913,
it was noticed that a large number of soldiers in France and Flanders were falling victim to a disease the nature of which was not clearly understood. It was an infectious disease because men were affected who shared the same tents, huts or billets. It bore some resemblance to rheumatism in that pain in muscles and bones was a prominent symptom. It was also rather like influenza except for an absence of nasal catarrh.
The disease at first was given many names. Thus cases were called " P.U.O.," an army term meaning " pyrexia of uncertain origin." They were also called " rheumatism " and "influenza" and "myelitis" and "lumbago." If the cases were seen at a late date when palpitation and brea,thlessness had become prominent, they were often called " cardiac neu- rasthenia " or " disordered action of the heart " (" D.A.H.").
Soon, however, it was felt that these diagnoses were inaccurate ind a serious attempt was made to study the disease. The
- arliest contributions to its literature were made by Dr. J. W.
McNee, and others who worked with him. Afterwards several French Fever Committees were formed by the British medical tuthorities. One of these worked in connexion with the Ameri- can Red Cross; another, known as the "War Office Trench 7 ever Committee," had a hospital in Hampstead. This Tcmmittee was presided over by Sir David Bruce; the director )f its research work was Col. William Byam. Both Com- nittees infected volunteers and the conclusions reached, though hey differed on points of detail, were substantially the same. Trench fever is a louse-borne disease. The lice do not be- ome infectious at once after feeding on a trench-fever patient; here is a latent period of some 8-12 days before they are danger- us to other people. Thereafter the excreta of the lice, rather ban their bites, are infective. If these infective excreta be ubbed into a scratch or scarification trench fever develops i about eight days. The importance of this discovery about he excreta lies in the fact that persons may contract the con- ition who have never had lice upon them. The excreta is a ry powder, easily blown about, and so apt to reach the clothes, t remains infective for long periods and even when exposed 5 sunlight. Water on the other hand seems to diminish its ifectivity quickly.
The blood of trench-fever patients is infective to other patients hen injected into their veins. Thus the parasite circulates in ic blood. The parasite is also in the louse excreta. It has ot, however, so far been positively identified, though there is certain amount of evidence, that it is one of the so-called ickettsia bodies. In this connexion the names of Dr. G. A. > rkwright and Prof. A. W. Bacot must be mentioned, i The disease is protean in its manifestations. A proportion of the ises begin suddenly with great muscular weakness and exhaustion,
- adache, furred tongue and blood-shot eyes. Other cases come on
adually, the above symptoms increasing daily in intensity. The
- itient feels very ill and usually develops a temperature-rise to
I )2F. or 103 F. Various types of temperature have been described, i some instances there is but one wave lasting two or three days; other instances a " saddle-back " curve is shown, the tempera- re falling slightly and then rising again. Some patients relapse finitely on the fifth day, others about the eleventh day. Others ain relapse at irregular intervals for long periods, each relapse k"ing a " spike " of temperature of short duration. I In a few cases there is no rise of temperature. Thus three volun- ' ers were infected with the same batch of louse excreta. All of the ree developed symptoms of trench fever but in one instance the temperature remained normal. Yet lice, subsequently fed on this patient, were able to transmit the disease to other volunteers all of whom developed rises of temperature. (For similar disease-carry- ing by body-lice see TYPHUS FEVER.)
The skin pains of trench fever are characteristic. They do not as a rule appear until a few days after the onset. They are of a boring, gnawing character and may be so violent that the patient cannot even bear the weight of the bed clothes. Again they may be very slight or absent.
The diagnosis is easy in early cases but the disease tends to run a very chronic course. In one case a patient labelled as a " neuras- thenic " was found to infect lice four years after his initial attack. A percentage of patients become chronic invalids, others develop symptoms of functional heart trouble, others have nervous symp- toms. It is probable that all these patients remain infected. The most reliable signs on which a diagnosis can be founded jn the chronic stage are: (i) the patient's history, especially the state of his health before and after the initial attack; (2) .the nature of his relapses; (3) the tenderness commonly met with on gently pinching the skin of the front of the leg (over the tibiae) ; (4) the presence of heart or nervous complications, e.g. breathlessness on exertion, pain, palpitation, gross tremor, etc.
The treatment is very unsatisfactory. At present no drug is known which will end the condition as quinine will end malaria. Thus it is necessary to attempt to build up the patient's strength against his infection. He should if possible lead an open-air life, he should have exercise, good plain food and cheerful surroundings. Some authorities lay stress on the value of thyroid, gr. 2 daily, in these cases. Others believe in iron tonics. Recent observations have suggested that the muscular weakness which follows the disease prevents the proper opening of the chest in respiration and so interferes with the suction action of the opening chest on the great veins. On this account the wearing of an abdominal belt has been recommended. It causes the patient to breathe with his chest and so tends to the restoration of thoracic movement. The disease is very disabling and its marked tendency to relapse makes it very distressing to the victim, who can never count on his health. Change of weather and wet weather seem specially to conduce to relapses. (R. M. Wl.)
TRENCH ORDNANCE. The need of some form of easily transportable weapon for bombarding an enemy's works or his men from trenches immediately facing them, instead of from a distant artillery position, has made itself felt throughout the history of siege warfare. The use, in the trenches, of small mortars (known as " cohorns'," from the Dutch engineer Coehoorn who designed them) was habitual in the sieges of the 18th century, and the great Carnot early in the igth century proposed their use on a very large scale for the purpose of attacking personnel protected from direct fire by breastworks. The introduction of rifled ordnance, and the consequent modifications in siege
methods, led to the disappearance of these cohorns. Neverthe-
less the need of a trench-mortar was felt in both of the two great
sieges of modern times Vicksburg and Port Arthur in which,
before the World War, trench fighting was close and prolonged.
In these cases mortars of wood and hoop-iron, strong enough to
bear the strain of throwing small bombs a short distance, were
improvised by the troops themselves. After the experience of
Port Arthur, however, European designers took up the question,
and several types were worked out, of which three, the Belgian
Aasen, the German official " Military Engineering Committee's "
design, and the Krupp, initiated progress along three different
lines which were followed up in the World War. The first named, which was used in action even before the World War at the siege of Adrianople, 1913 was the prototype of the light trench-mortars; the second, with few important modifications, remained in service throughout the WorldWar, and represents the adaptation of standard artillery ideas and elements to the new problem, while the third introduced the principle of the " stick-bomb," fired from a small-bore high-pressure cannon. The Aasen, besides opening the series of light trench-mortars, introduced the principle, opposite to that of the Krupp, of low pressure.
The history of trench-mortars in the World War is a record, first of a continually increasing demand which the supply authorities in the various belligerent countries could not meet; then of a period, coinciding with the full development of position-warfare methods of tactics, in which well-designed weapons with ample ammunition supply played an increasingly important part; and lastly of a period in which, under pressure of new tactical needs, the " trench " mortar strives to become a gun of
