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546 special situations provided for. Other standardized articles were: dummy attack figures, dummy heads, snipers' suits and portable covers for machine-guns these last-named reversible squares of scrim 8 ft. by 8 ft., green on one side, brown on the other; made very light and portable for use in the field.

Manufacture. Although a description of the methods of pro- duction is beyond the scope of this article, discussion of the principles and practice of camouflage would not be complete without some reference to the important part played by mate- rials, particularly canvas and paint.

Canvas is not an ideal material, being very susceptible to damage by weather, but it is easy to manipulate and is cheap. From the point of view of appearance, it is inferior to raffia, which, however, suffers from the hitherto insuperable disadvantage of inflamma- bility. " Water" paints were generally employed for canvas for the reason that oil paints, which are more durable, are too inflammable, even to the extent of spontaneous combustion. This latter dis- ability was the cause of disastrous fires where rolls of painted can- vas were stored. Green dye proved too fugitive, but brown dyes proved satisfactory. Generally speaking, canvas and paint do not adequately fulfil the conditions of lightness and durability.

(F. J. C. W.)

III. NAVAL CAMOUFLAGE

The painting of vessels of war with a view to reducing their visibility and so adding to their fighting value is by no means a modern development. The Romans are known to have painted their galleys; " seven kinds of paint were used, viz. purple, violet, yellow, two kinds of white, and green for pirates in order that their resemblance to the colour of the waves might make them less conspicuous."

Camouflage on various lines but with the invariable idea of reducing visibility had been attempted in the British navy for many years before the World War. None of these schemes had met with any success, and each in turn had been abandoned after furtive trials. The two factors which led to this abandonment were first the failure to realize that anything in the nature of invisibility at sea is possible of attainment, and secondly the inability of the proposers of these schemes to provide definite instructions of a practical nature by which vessels could be painted with some degree of consistency.

The Board of Admiralty eventually adopted a partial form of camouflage by painting aU vessels a light grey as opposed to the black hulls and light upper works previously in force. But even this simplest form of all protective measures was somewhat hap- hazard in application, since the individual vessels of a squadron varied considerably in colour, ranging from a light bluish grey to a dark slate according to the ideas of the commander.

It was not until 1917, during the height of the submarine peril, that a practical scheme having a definite end in view and for- mulated on scientific lines was put forward and officially adopted by the British authorities. This scheme embodied entirely new ideas on sea camouflage, and was rescued from the early disease which had attended all its predecessors by the fact that the proposer was able to supply designs to scale in large numbers, all bearing out a central idea. It was called for distinction's sake in official documents " Dazzle Painting." The sole object of dazzle painting was so to distort the normal appearance of a vessel that her actual course became a matter of doubt in the mind of a submarine officer, the estimation of a vessel's true course being the prime factor required to ensure successful attack.

Dazzle painting was intended primarily for application to merchant ships. These vessels were in far greater need of pro- tection than warships owing to their slow speed and vulner- ability and also from the fact that the enemy were making a concerted attack on England's supplies of food and materials essential to the conduct of the World War.

Warships as a rule possessed high speed and were moreover protected by destroyers, a type of vessel which while being the most deadly opponent of the submarine was comparatively immune from attack. A certain number of war-vessels were however dazzle-painted. These were chiefly ships engaged on convoy work, although a certain number detailed for special duties such as mine-laying and patrol service found this special form of protection of valuable assistance.

At first sight it would appear impossible to treat a vessel with paint in such a way that an experienced seaman could be deceived as to her actual course, but dazzle-painted ships proved that this could be done. Juxtaposition of violently contrasting colours, black and white predominating, combined in accordance with the laws of perspective, could make it extremely difficult to judge the accurate inclination of a vessel even at a short distance.

In the early stages of dazzle painting a large range of colours was employed to achieve the end in view. Experience showed that this could be attained by a much smaller number, and to- wards the end of the war the principal colours in use were black, white, and blue, these being employed in varying intensity.

Another factor which led to the simplification of the colours used was the knowledge that the German naval authorities had introduced the use of colour screens in their submarine peri- scopes with a view to reducing the camouflaged ship to a sil- houette, and so neutralizing the effect of the colours used. These screens however had no effect whatever on a design depending solely on black, white, and blue for its contrast. Shortly after its adoption by the Admiralty dazzle painting was incorporated under the Defence of the Realm Act and the whole merchant service was ordered to be painted. Numbers of war -vessels operat- ing with merchant ships were also painted : these comprised chief- ly convoy cruisers, sloops and destroyers. The xoth Cruiser Squad- ron, engaged in blockade duties and composed entirely of large merchant ships, was also painted. These vessels were specially liable to attack, being at sea for long periods in submarine- infested zones and constantly under slow speed or altogether stopped for boarding purposes.

On the introduction of the scheme a considerable volume of maritime opinion was directed against it from lack of a proper grasp of its objects and because it appeared to render a vessel more conspicuous than was the case when painted grey. In point of fact at the date of the submission of the scheme the proposer, who was on patrol duty in the channel, had noted that all transports were painted a dead black from water-line to truck. The opposition, however, rapidly disappeared as soon as the ob- jects of the scheme were thoroughly grasped and the rapidly increasing numbers enabled seamen to judge for themselves the difficulties of accurately estimating the accurate courses of dazzle-painted ships met with at sea.

The organization for producing designs in great variety and arranging for the rapid application of the designs to large num- bers of vessels of great diversity of types was as follows:

The mercantile marine was divided into 37 classes of characteristic types. For each type a small wooden modijl was made to scale and on this model a design was painted in wash colours. It was then carefully studied in a prepared theatre through a submarine peri- scope with a view to obtaining the maximum distortion. Behind the model were placed various sky backgrounds, the conditions of an average day at sea being obtained as nearly as possible. The model was slowly revolved on a turntable and observed from every point of view, any necessary alterations and additions being made until the distortion became such that an independent observer found it a matter of considerable difficulty to judge its orientation.

The model was then handed to a trained plan-maker who trans- ferred the design in colour to a 1-16 in. scale plan on white paper showing port and starboard side (see Plate I.). Each colour on the plan was numbered to conform to the official colour charts, which gave a complete range of all colours used in dazzle painting (see Plate II.). It was one of the important factors essential to the suc- cess of the scheme that these colours should be rigidly adhered to by painting contractors.

The Dazzle Department was represented at all the principal ship- ping ports by one or more officers specially trained for the work. These officers were responsible for the issue of plans and the super- vision of all ships painting in their districts. This work entailed a great deal of highly skilled supervision, as the actual painting fell upon the local painting contractors, whose men were entirely new to this kind of work. With the rapid expansion of the scheme how- ever, upwards of 100 vessels were sometimes in hand at one port, difficulties were overcome and the work proceeded smoothly.

Soon after the establishment of the Dazzle Department, inquiries were made by the Allied maritime governments as to the efficacy of this new form of defence against the submarine. The French Ministry of Marine attached three officers for training under the new scheme and shortly afterwards set up a