LIBRARY 
 
 OF THE 
 
 UNIVERSITY OF CALIFORNIA. 
 
 GIFT OF 
 
 Class 
 
DEPARTMENT OF COMM D LABOR 
 
 GEORGE M. BOWERS. Commissioner 
 
 THE PHOTOGRAPHY OF AQUATIC ANIMALS IN THEIR 
 NATURAL ENVIRONMENT 
 
 FROM BULLETIN OF THE BUREAU OF FISHERIES 
 
 >F FISHERIES DC- 
 
DEPARTMENT OF COMMERCE AND LABOR 
 BUREAU OF FISHERIES 
 
 GEORGE M. BOWERS. Commissioner 
 
 THE PHOTOGRAPHY OF AQUATIC ANIMALS IN THEIR 
 NATURAL ENVIRONMENT 
 
 FROM BULLETIN OF THE BUREAU OF FISHERIES 
 Volume XXVII, 1907, Pages 41 to 68, Plates H to V 
 
 BUREAU OF FISHERIES DOCUMENT NO. 635 
 ISSUED AUGUST 22 1908 
 
 WASHINGTON 
 
 GOVERNMENT PRINTING OFFICE 
 1908 
 
THE PHOTOGRAPHY OF AQUATIC ANIMALS IN THEIR NATURAL 
 
 ENVIRONMENT 
 
 By JACOB REIGHARD 
 
 Professor of Zoology, University of Michigan 
 
 BUREAU OF FISHERIES DOCUMENT NO. 635 
 
 41 
 
 174289 
 
CONTENTS. 
 
 Page. 
 
 Introduction : 43 
 
 Principles of photography of submerged objects, 43 
 
 A new method of photographing submerged objects with camera above the surface 40 
 
 Previous attempts to photograph submerged objects by means of a submerged camera 51 
 
 Boutan's first apparatus 51 
 
 Boutan's second apparatus 54 
 
 Boutan's third apparatus 54 
 
 Boutan's methods of artificial illumination 57 
 
 Bristol's subaquatic camera 59 
 
 A new subaquatic apparatus 00 
 
 The camera CO 
 
 The water-tight box ^ 62 
 
 Using the apparatus C3 
 
 Some limitations of subaquatic photography 06 
 
 Literature cited 68 
 
 42 
 
PHOTOGRAPHS TAKEN WITH CAMERA SUBMERGED. 
 
THE PHOTOGRAPHY OF AQUATIC ANIMALS IN THEIR NATURAL ENVIRONMENT. 
 
 BY JACOB REIGHARD, 
 Professor of Zoology, University of Michigan. 
 
 INTRODUCTION. 
 
 Many things have contributed in recent years to extend the use of photography 
 into fields of natural history not previously occupied by it. Dry plates and films 
 have been made more rapid and, with the advent of the nonhalation and orthochro- 
 matic sorts, have been adapted to every use; with new sorts of optical glass it has 
 been possible to construct photographic lenses of great speed; cameras and acces- 
 sories have been made portable and suited to a variety of needs. As a result we 
 find in scientific publications, as well as in more popular books and periodicals, 
 excellent photographs of living animals and plants in their natural environment. 
 Students and lovers of birds, field naturalists and hunters of big game have all 
 contributed their part. Birds have been photographed on the wing and while 
 engaged in their domestic duties, on the nest in almost inaccessible high trees, 
 on mountain crags, and on the faces of cliffs. Mammals have been photographed 
 in nature under a great variety of conditions. Reptiles, amphibians, insects 
 everv variety of terrestrial animal has been pictured by the lens. 
 
 Quite in contrast has been the limited use of photography for aquatic organisms. 
 Shufeldt (1898), Dugmore (Jordan & Evermann, 1902), Saville-Kent (1893), Fabre- 
 Domergue (1898), have from time to time succeeded in making excellent photo- 
 graphs of animals in aquaria under more or less artificial conditions, but the work 
 has been carried scarcely beyond this (see Boutan, 1893, 1898, 1898a, 1900, and 
 Rudaux, 1908). The present paper deals rather with the photography of aquatic 
 organisms, not merely in their native element, but in their native environment and 
 under normal conditions. It attempts to show how they may be photographed, 
 not by taking them from their native haunts and placing them in artificial containers, 
 but by carrying the camera into the field. The methods described make it possible 
 to do in some measure for aquatic animals what has been done for birds and other 
 terrestrial forms. 
 
 PRINCIPLES OF PHOTOGRAPHY OF SUBMERGED OBJECTS. 
 
 In air the naturalist can by one method or another photograph what he sees. 
 When he looks into clear water he may see much that it seems possible to photo- 
 graph. If the surface is disturbed objects beneath it appear distorted and waver- 
 ing, but if the surface is smooth they may appear as sharp and steady as though 
 
 43 
 
44 
 
 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 viewed through air alone. In the latter case the photographer may set up his 
 camera and find that he can get a perfect image on the ground glass; but if he 
 then exposes a plate with the expectation of getting a good negative he will be 
 sorely disappointed. Only rarely does he get any image at all of what lies beneath 
 the water's surface. Usually the negative shows only the surface itself, and that 
 appears as opaque as though the camera had been pointed into a lake of tar. The 
 writer has often attempted such photographs, to find on his negative no visible 
 impression of the fish which showed so clear on his ground glass. This is doubtless 
 a common experience. Why is it? 
 
 Explanation will be clearer by referring to the diagrammatic figure 1, where 
 the camera (c) is pointed toward a fish (x-y) beneath the surface (a-b) of the 
 
 water. The fish 
 
 ^^ is illuminated 
 
 chiefly by rays of 
 light which enter 
 the water almost 
 vertically. The 
 rays of light x x', 
 y y', reflected 
 from the fish, 
 which strike the 
 surface of the 
 water from below 
 at an angle less 
 than 48 35' with 
 the vertical, 
 emerge into the 
 air, while at the 
 same time they 
 are bent from 
 their course, as 
 shown in the fig- 
 ure. Some of 
 
 these rays converge to the lens, and thence diverge to form on the ground glass 
 the image i i'. When the photographic plate is exposed these rays, with the rays 
 from other submerged objects, form an image on it, as they do on the ground 
 glass. Yet this image does not appear in the negative, for if the surface of the 
 water is smooth it acts as a single great mirror which, although it permits a 
 part of the light to penetrate, yet reflects another part, greater the more obliquely 
 the light strikes the surface. For this reason the images of sky and trees 
 and other distant objects are often seen mirrored on the surface of smooth water. 
 Some of these reflected rays (z z', w w'), after leaving the surface of the water, 
 enter the lens of the camera and form an image. The fish is a near object and if 
 the camera is focused upon it the image of the fish is sharp on the photographic 
 plate. The reflected rays from the water's surface come usually from distant objects, 
 commonly sky or clouds. When the camera is focused on the fish a sharp image 
 
 FIG. 1. Diagram illustrating the photography of objects beneath the water by a camera above 
 the surface. For explanation see the text. 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 45 
 
 of these distant objects is formed, not on the photographic plate, but in a plane 
 situated somewhere between that plate and the lens, as at / I' . After forming 
 the image at / /' these rays again diverge and strike the photographic plate. The 
 plate is thus flooded by light from distant objects that are wholly out of focus, so 
 that such rays do not form a distinct image on it. This reflected light is usually 
 brighter than the light which forms the image of the fish. It affects the plate 
 with greater intensity, so that when the plate is developed the image of the fish is 
 quite obscured by the general fog produced by the brighter light. There appears 
 in the negative only a uniform dark haze, which represents the surface of the water. 
 
 If the ground glass is put in place and brought b\ T focusing into the plane / /', 
 then the sharp image of distant clouds and trees is seen on it, while the image of 
 the fish lies behind the ground glass and is no longer clearly visible. If the water 
 is smooth, a plate exposed under these circumstances gives a sharp negative of 
 these distant objects, but does not show the fish. 
 
 If one looks at the fish in the water from the point C it is seen clearly, because 
 its image is focused on the retina, while the images of more distant objects mirrored 
 in the water's surface fall in front of the retina, and the objects from which they 
 come are therefore not seen. The observer neglects the glare of light from these 
 distant objects, fixes his attention on the fish, and sees it. If now, while still 
 looking toward the fish, he adjusts his eye to distant objects by relaxing the ciliary 
 muscle, these are clearly seen mirrored in the surface of the water, while the fish is 
 no longer sharply seen. Similarly, if a mirror is laid on the ground so as to reflect 
 the clouds and its image is examined by focusing in a camera, it is impossible to 
 get at the same time on the ground glass a sharp image of the clouds reflected in 
 the mirror and of the frame of the mirror or other near object. It is only when 
 the mirrored object lies near the surface of the water that its image can be focused 
 on the photographic plate or retina at the same time with that of a submerged 
 object near the surface. It nearly always happens that the light entering the 
 camera from distant objects mirrored in the surface of the water is so much more 
 intense than that from submerged objects that the images of the latter are quite 
 obliterated on the photographic plate. Sometimes, on the other hand, when the 
 camera is pointed nearly vertically into the water at an object over a light-colored 
 bottom, the emerging light is more intense than the reflected light, and there is 
 obtained a more or less fogged negative which shows submerged objects. This is 
 the more apt to be the case if the photographer has the sun at his back. (See 
 Saville-Kent, 1893.) At other times, within the limits of the reflected image (not 
 the shadow) of a dark-colored bridge or building or of dense foliage, one may obtain 
 a fogged negative, showing submerged objects. In this case also the partial success 
 is due to the fact that the reflected light is less intense than that which comes from 
 the submerged objects to be photographed. It is not often, however, that the 
 submerged objects that one wishes to photograph are found within the reflected 
 images of dark-colored backgrounds of sufficient size and far enough away. 
 
 The above discussion is based on the assumption that the surface of the water 
 is smooth so that it acts as a single large mirror. If the water surface is disturbed 
 it is broken into numerous smaller surfaces, concave, convex, or plane, and each 
 of these acts as an independent small mirror. These form distorted images of 
 
46 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 portions of distant objects, of natural size, magnified or reduced; and the light 
 from them entering the camera affects the photographic plate in such a way as 
 to obliterate the dimmer image of any object lying beneath the water. At the 
 same time the light from the submerged object is refracted in various directions 
 as it emerges into the air through the irregular surface of the water, so that its 
 image as formed on the retina or ground glass is neither sharp nor steady. 
 
 From the foregoing discussion it appears that attempts to photograph sub- 
 merged objects with a camera placed in air can result in only partial success, and 
 this but rarely. Failure is due to the fact that the photograph is made through 
 the surface of contact of two media, water and air, of very different refractive 
 powers. If this surface is not perfectly smooth the light from an object beneath 
 it is, upon emergence, refracted unequally at different parts of the surface and can 
 not form a clear image on the ground glass. Whether the water is smooth or rough 
 its surface reflects a part of the light which strikes it, and thus acts as a mirror. 
 This reflected light makes it impossible, except under unusual conditions, to obtain 
 photographs of submerged objects. To obtain such photographs the surface of 
 the water must be smooth and light reflected from it must not enter the camera. 
 Two modes of procedure suggest themselves: 
 
 (1) The camera may remain above the surface of the water. In that case the 
 surface of disturbed water must be rendered smooth and the light from objects 
 above water must be prevented from striking its surface at such angles as to enter 
 the camera in sufficient amount to fog the plate. Methods devised by the writer 
 for accomplishing these two results are taken up and illustrated in the following 
 section. 
 
 (2) The camera may he placed heneath the surface of the water, so that this 
 surface does not intervene between the camera and the object to be photographed. 
 The light which enters the camera is therefore neither refracted nor reflected at 
 this surface, and images may be obtained on the ground glass as clear and steady 
 as though viewed through air alone. Methods of the writer and others for accom- 
 plishing this are described and illustrated in the final section of this paper. 
 
 A NEW METHOD OF PHOTOGRAPHING SUBMERGED OBJECTS WITH THE CAMERA 
 
 ABOVE THE SURFACE. 
 
 It was pointed out in the preceding section that if the camera with which sub- 
 merged objects are to be photographed is to remain above the surface of the water 
 means must be found (1) greatly to reduce the amount of reflected light entering 
 the camera from the surface of the water, and (2) to render the surface of the water 
 smooth. We may consider first the case in which the surface of the water is smooth, 
 so that it is necessary merely to minimize surface reflection. 
 
 The method to be described is best adapted to objects in water not more 
 than 2 or 3 feet deep, and the best results are obtained when the water is less 
 than a foot in depth. Any type of camera may be used, but since the objects to 
 be photographed are necessarily quite near the camera they are out of focus with 
 a fixed-focus camera, so that the best results are obtained when the camera is one 
 that can be focused. Since the objects to be photographed are usually in motion, 
 and since the surface of the water may at any time be roughened by a puff of wind, 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 
 
 47 
 
 it is best to use a lens suitable for instantaneous exposure a lens of a speed not less 
 than f 8. The operator should first select the point from which the picture is to 
 be taken. He should, of course, have the sun at his back or to one side. If possible 
 he should stand on the bank or on some fixed support which extends above the 
 surface of the water. From such a position the camera is at a greater height and 
 may usually be directed at the surface of the water at an angle of about 45 or 
 less from a vertical extending upward from this surface. Rays of light from sub- 
 merged objects striking the surface of the water from below at an angle of 48 35' 
 from a vertical drawn downward (or at a less angle), emerge. They may thus, 
 after refraction, reach the camera as indicated by the line x yf i' in figure 1. Rays 
 which strike the surface of the water from below at an angle of more than 48 35' 
 with the vertical are, on the 
 other hand, reflected at the 
 surface so that they do not 
 emerge and enter the camera 
 but pass down again into the 
 water, as indicated by the 
 line x m n in figure 1 . 
 
 If the operator is unable 
 to find a fixed emergent sup- 
 port for the camera he may 
 make the exposure while 
 standing in the water. The 
 camera may then be held in 
 the hand or may be supported 
 on a tripod which rests on 
 the bottom. As the legs of 
 the tripod are likely to sink 
 into the bottom they should 
 be extended to their full 
 length. Where the bottom 
 is firm an elevated position 
 may be obtained for the 
 camera by using a tripod with legs some 10 feet long, such as dealers sell for use 
 in making pictures of large groups. In such tripods one leg forms a ladder by 
 which the camera may be reached. 
 
 The tripod top should consist of two rectangular wooden pieces, as shown in 
 figure 2 and in section in figure 1. To the lower piece, which has a large circular 
 opening at its center, the legs are attached. The camera is fastened by the tripod 
 screw to the upper piece in such a way that one of the legs projects directly backward 
 instead of directly forward, as is usual. The two pieces are hinged together at one 
 edge, so that they may lie parallel to one another or may be separated like the covers 
 of a book until the upper piece forms an angle of 90 with the lower. A rod is 
 pivoted by one end to the upper piece at the middle of its free edge, so that it swings 
 freely in the vertical plane. This rod passes through a perforated metal block piv- 
 oted by one end at the middle of the free edge of the lower piece so as to swing freely 
 
 FIG. 2. Tripod top by means of which the camera may be inclined at any 
 angle. For explanation see the text. 
 
48 BULLETIN OF THE BUKEAU OF FISHERIES. 
 
 in a plane vertical to that piece. When the two pieces are separated by moving the 
 upper one on the hinge which connects them the rod slips through the opening in 
 the block and may be firmly clamped at any point in its length by means of a 
 set screw. Thus the upper piece may be held firmly at any angle to the lower 
 piece from to 90, and the camera may be pointed at the water at any 
 desired angle. The position in which the legs of the tripod are attached permits the 
 camera to be pointed directly downward in the space between the two front legs, 
 whereas if the legs were attached in the usual manner with one leg in front it would 
 be impossible to bring the camera into the vertical position. Tripods of this type 
 are to be found in the market or may be made from an ordinary tripod by any 
 mechanic. 
 
 When the operator has placed his camera and roughly adjusted it, he should 
 set up a screen to cut off the light reflected from the surface of the water into the 
 camera. Any piece of dark fabric, a blanket, shawl, or for small objects even a 
 coat, may be used. It may be supported by hand or tied to poles stuck in the 
 bottom. The writer carries into the field a screen made by sewing together pieces 
 of black calico to form a sheet either 6 or 9 feet square. To three of the edges 
 of this, at intervals of about a foot, are sewn pieces of tape each about a foot long and 
 attached at its middle so as to leave 6 inches projecting on each side. One piece 
 of tape should be attached to each corner of the screen. Two poles are cut of 
 sufficient length to project 6 to 10 feet above the w r ater when firmly set in the 
 bottom. The poles are sharpened at one end, and beginning at the unsharpened 
 end the square of calico is tied to them by the opposite edges by means of the 
 tapes. The third side to which tapes are attached is the upper, between the 
 unsharpened ends of the poles. The poles are now thrust into the bottom on that 
 side of the camera opposite the object to be photographed and so that they slant 
 toward the camera. The screen (s s', fig. 1) is thus stretched upward from the 
 surface of the water in a slanting position, so that its upper edge is nearer the camera 
 than its lower. If the two poles are pulled together by the weight of the cloth or the 
 action of the wind so that the screen sags, a third pole tied between their upper 
 ends will keep them apart, while the tapes on the upper edge of the screen will 
 serve to attach it to the cross-pole. 
 
 If the operator now returns to the camera he will see the screen mirrored in 
 the surface of the water. The object to be photographed should fall within the 
 limits of this mirrored image as seen from the camera. a If it does not, the screen 
 or the camera must be shifted until it does. The operator will see also the shadow 
 of the screen. This should not fall on the object to be photographed. The screen 
 should, if possible, be adjusted by slanting it or by moving one of the poles so that 
 the sun strikes it nearly edgewise, but yet does not strike that face of it which is 
 toward the camera. If this adjustment is properly made the shadow of the screen 
 is a very narrow band, which lies beneath the screen and a little nearer the camera 
 than its lower edge. The full sunlight then falls on the object while the rays from 
 
 a Saville-Kent (1893) apparently utilized this principle when photographing with a vertical camera on the Australian 
 barrier reefs, but Rudaux (1908) stated the principle explicitly as applied in photographing in natural waters with a 
 vertical camera objects within the reflected image of the tripod top. Neither recognized the broad application of the 
 principle here described. 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 49 
 
 distant objects which would otherwise be reflected into the camera from the surface 
 of the water are cut off. If the sunlight is permitted to fall on that face of the 
 screen which is toward the camera, it is reflected from the screen to the surface of 
 the water and thence into the camera. A picture taken under these conditions 
 may show, besides the object under the water, also the screen itself, although this 
 image of the screen is usually so faint that it does not interfere with the use of the 
 picture for scientific purposes. 
 
 When the screen has been properly set the operator has merely to adjust the 
 camera and make the exposure in the customary way. If the subjects are fish they 
 will usually have been frightened away, but if the fish are engaged in nest building 
 or in some other occupation that attracts them to a particular spot, they will, in 
 most cases, return after a tune varying from five minutes to an hour. The operator 
 has merely to remain quiet until this happens. The photographer may focus his 
 camera on the spot to which the fish is likely to return and then withdraw and 
 operate the camera from a distance by pulling a string or pressing a bulb when 
 the fish returns. The method is of most use in securing photographs of the nests 
 and habitats of fish in shallow water, yet the writer has succeeded by means of it 
 in making some satisfactory photographs of fish on the nest. 
 
 The result of using the screen is shown in figure 1 of plate ni, which is a photo- 
 graph of the nest of a small-mouthed black bass. The screen in this case was stretched 
 on a frame and was held by hand. Within the limits of the reflection of the screen 
 in the water's surface the bottom may be seen clearly. At the center are the larger 
 stones which form the bottom of the nest, and these show sharply the details of 
 then" markings. Outside the limits of the reflection of the screen the bottom is not 
 clearly visible; its image has been obscured on the sensitir'e plate by the bright 
 light reflected from the surface of the water. The sun struck the back of the screen 
 from the left, as is shown by the shadow which lies close to the screen. Within 
 the limits of this shadow the plate was underexposed and details of the bottom 
 are not visible. With a longer exposure as good a negative could have been made 
 of what lay in the shadow. 
 
 If the surface of the water is not smooth it may be made so by a water glass, 
 which may be constructed as follows (fig. 1, pi. iv): A square frame is made of 
 heavy galvanized iron, and measures 3$ inches deep and 12 inches on each side 
 within. One of its edges (the top) is turned outward three-fourths of an inch and 
 then downward one-half inch to form a lip. This stiffens the frame and tends to pre- 
 vent water from slopping into it. The lower edge of the frame is turned outward 
 about half an inch to form a flat surface, against which the glass, 13 inches square, is 
 bedded in aquarium cement. After the glass is in position four trough-shaped pieces 
 are soldered to the sides of the frame and to one another in the manner shown in the 
 figure. The free edges of these pieces project inward beneath the lower surface of 
 the glass and support it. Before the pieces are soldered into place cement is placed 
 between them and the lower face of the glass. The whole border of the glass is thus 
 bedded in cement on both surfaces and at the edge. To protect the glass when not in 
 use a flat cover is provided, which fits against its lower face. Such a water glass may 
 
 B. B. F. 19074 
 
GO BULLETIN OF THE BUREAU OF FISHERIES. 
 
 be floated over the object to be photographed and a screen set up independently 
 of it, or the screen may be attached to the glass itself. For the latter purpose a 
 piece of half -inch band iron may be bent to form the three sides of a rectangle, 
 8 by 12 inches, and this may be riveted as a bail (fig. 1, pi. iv) to the inside of the 
 frame, about 8 inches from one side. The bail should turn on the rivets so that it 
 may be depressed into the frame when not hi use. A screen may be formed by 
 raising the bail and tying a piece of black cloth from it to the opposite side of the 
 frame. In shallow, running water it is desirable to support the water glass from 
 the bottom in order that it may not sink so much as to displace or distort the 
 object to be photographed. It may be supported on four iron rods which run 
 through metal sleeves soldered to the four corners of the frame. The rods may 
 be fixed in any position in the sleeves by means of set screws, and may project 
 upward far enough to support the upper edge of the screen. A water glass 
 arranged in this way is shown in figure 2, plate iv, where it is being used for observa- 
 tion, but with the same glass photographs were obtained of lamprey eels in the act of 
 spawning. Such a photograph is reproduced in figure 2, plate HI, where the rough 
 surface of the running water made the use of the water glass imperative. The 
 white bands across the picture are the edges of the frame of the water glass. Outside 
 this frame at the right, where the water is rough, little is visible. The screen was 
 almost as necessary as the water glass. 
 
 The writer has used water glasses of this type varying in size from 1 to 3 feet 
 square. Those of 1 foot square are of use chiefly for observation, and even for 
 this purpose the screen is a valuable addition. Those of 3 feet square are so 
 unwieldy that a vehicle of some sort is needed to carry them. The size most suitable 
 for field photography is 2 feet square, since this may be transported by hand. 
 
 The method described in this section is suited only to shallow water, where 
 the camera may be supported from a firm substratum. In deeper water the 
 unsteadiness of the boat would interfere with the manipulation of a water glass or 
 a screen. It might be possible, however, to construct a boat of which the water 
 glass and the screen should form constituent parts. The method described permits 
 only of views at angles of from about 48 to 90 to the water's surface. Since it is 
 not practicable to place the camera far above the water at these angles or to use 
 screens of very large size, the pictures that may be taken are of near objects and 
 the field covered by them is of limited extent. If a water glass is used, the camera 
 must be near it and the field is limited by its frame. The method is, however, the 
 only one known to the writer for certain kinds of work. Often, as in the case of 
 the bass nest shown in figure 3, the objects to be photographed are in water so 
 shallow that the camera must be placed above its surface; there is not room for it 
 beneath. Often, though the object may be in deeper water, it is so surrounded 
 by vegetation that it can not be seen from a little distance except from above. It 
 must then be photographed from above. Where the water is both shallow and 
 disturbed, as in small streams, the use of a water glass is essential. There are there- 
 fore many objects about the borders of lakes and in streams to which this method 
 may be applied when no other known method is available. On the other hand, 
 wherever it is possible to use a submerged camera, results may be obtained with 
 greater ease and certainty in the mariner shown in the section which follows. 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 51 
 
 PREVIOUS ATTEMPTS TO PHOTOGRAPH SUBMERGED OBJECTS BY MEANS OF A 
 
 SUBMERGED CAMERA. 
 
 Photography by means of a submerged camera was first attempted by Dr. L. 
 Boutan, of Paris, at the seaside laboratory of Roscoff, in 1893. His work was con- 
 tinued through the seasons of 1895, 1896, 1897, and 1898, and the results have been 
 published in four communications (Boutan, 1893, 1898, 1898a, 1900). Boutan's 
 apparatus was used wholly in the sea, and he has given to his method the title "la 
 photographic sous-marine." I shall use instead the broader term subaquatic 
 photography, as indicating the wider application of the method to both fresh and 
 salt water. 
 
 Boutan made use of three forms of apparatus, which may be designated as his 
 first (1893), second (1896), and third (1898) apparatus. Each of these will be 
 briefly considered. 
 
 He was led to take up subaquatic photography by his study of the develop- 
 ment of the mollusk Haliotis. Finding it impossible to rear the larva? of this form 
 in aquaria and failing to collect them in their natural environment by the usual 
 methods, he decided to search for them by descending in a diver's suit. He was 
 struck by the beauty and interest of the submarine landscape and of its inhabit- 
 ants. He found it impossible to bring his experiences vividly before others by 
 mere verbal description and equally impossible, while inclosed in the cumbersome 
 garments of the diver, to make drawings, or even sketches, of what he saw. He 
 was thus led to try photography. He appears to have made no attempt to oper- 
 ate with a camera placed above the water, for, as he says, "when the surface of the 
 liquid is absolutely quiet the rays of light coming from submerged objects enter the 
 objective placed in air at the same time with the rays reflected by this mirroring 
 surface and that suffices to destroy all clearness in the images." He objected to 
 this method for the further reason that it could result in giving only a plan or 
 bird's-eye view similar to that which is obtained when landscapes are photographed 
 from the elevated car of a balloon. He therefore decided to construct an appara- 
 tus that could be used under water. It seemed to him possible to proceed on either 
 one of two principles: (1) "To have made an objective that could be immersed 
 directly in water.'' (2) "To have built a tight box in the interior of which the 
 ordinary objective could be placed protected from salt water." In his first and 
 third forms of apparatus Boutan made use of the second principle. In his second 
 attempt he made use, without success, of an objective immersed in water. 
 
 BOUT AX'S FIRST APPARATUS (1893). 
 
 In this apparatus Boutan made use of a detective camera of fixed focus, an 
 instrument intended to make instantaneous pictures at all distances beyond 3 or 4 
 meters without focusing. This camera was of the box form usual in detective 
 cameras. It was provided at the front with an opening for the lens and above 
 this with two openings for the finder. At the front there was on one side a lever 
 or button which controlled the shutter and at the back a rod by the movement of 
 which it was possible, without opening the box, to change the plates, a number of 
 which were carried in the magazine of the camera. 
 
52 
 
 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 OB 
 
 This camera was inclosed in a copper box (fig. 3). The top of the box was 
 open and was stiffened by a projecting rim against which a cover could be clamped 
 by means of eight metal screw-clamps. The joint between the rim of the box and 
 the cover was made water-tight by means of a heavy rubber gasket let into rectan- 
 gular grooves in both the rim and the cover. The box was intended to be used 
 at considerable depths. The pressure of the water on its outside would at 10 
 meters depth be one atmosphere plus the pressure exerted by a column of water 10 
 meters high, while the pressure on the inside of the box would be what it was when 
 the box was closed at the surface, one atmosphere. Under these circumstances 
 there was serious danger that the excess pressure on the outside of the box would 
 force the water through between the rim and the cover in spite of the most care- 
 ful construction of the joint between the 
 two. To overcome this difficulty, the cover 
 of the box was provided at its center with 
 an opening which extended upward into a 
 metal tube, and to this tube there was at- 
 tached an air-filled rubber bag of about 
 3 liters capacity. When the box was sub- 
 merged the pressure of the water on the 
 bag was communicated to the air within, 
 so that the pressure on the inner surface 
 of the box was exactly equal at all depths 
 to that on its outer surface. Thus there 
 was no excess pressure on the outer surface 
 of the box to force the water inward against 
 a less pressure within. 
 
 The front of the box was provided with 
 three circular openings closed by plates 
 of glass with parallel surfaces. The one at 
 the center was opposite the lens; the two 
 above it were for the finder. A similar 
 opening on one side was also closed by 
 a glass plate and served for the finder. On the same side was a rod which 
 terminated at its outer end in a milled head. Its inner end extended, through a 
 stuffing box which was water-tight, to the interior of the box. By pulling the 
 rod in and out the shutter could be operated. A similar rod at the back of the box 
 could be slid in and out and served to change the plates. When in use the camera 
 was supported on a heavy tripod of iron. 
 
 The apparatus was used either while the operator remained in shallow water 
 with his head and shoulders above the surface or when he had descended to the 
 bottom in a diver's suit. When working in shallow water, he put on the diver's 
 suit in order to be protected from the water, but omitted the casque covering the 
 head and the heavy weight ordinarily attached to the back and front of the suit. 
 Thus arrayed, he placed the tripod in position and attached the camera to it. In 
 
 FIG. 3. Boutan's first apparatus. Box used in 1893 for 
 inclosing a detective camera to be used under water. 
 B, rubber balloon filled with air; D, handle at the 
 back for operating the magazine plate holder; O, open- 
 ing corresponding to the lens; OB, handle at the side 
 controlling the shutter; V, front finder; OV, lateral 
 finder. (Copy of fig. 1 in Boutan, 1893.) 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 53 
 
 order to bring the camera to bear on the object to be photographed, it was then 
 necessary to provide a way to determine when the image of the object appeared in 
 the desired position in the finder. This was accomplished by using a metal tube open 
 at both ends, one end of the tube being placed over the ground glass of the finder 
 and the other, which extended above the water, being applied to the eye. The tube 
 excluded the light from the space between the eye of the observer and the finder, 
 while at the same time the water within it was protected from agitation. By this 
 means it was possible to see clearly the image on the ground glass of the finder. 
 It was necessary merely to manipulate the handle controlling the shutter in order 
 to begin and end the exposure. The plate could then be changed by manipulat- 
 ing the rod at the back of the box and another exposure made at once without 
 taking the camera from the x water. Where it was possible to operate near shore, 
 it was unnecessary for the operator to put on the diver's suit or to enter the water. 
 He could set the camera in place from the shore and adjust it or make the exposure 
 while lying upon the bank. Boutan, indeed, made satisfactory photographs of 
 fixed animals in aquaria by immersing this apparatus in an indoor aquarium and 
 operating it by means of a string. By using a very small diaphragm he was able 
 to get clear images of objects at a distance of 15 centimeters from the lens, but 
 this required an exposure of three minutes. He obtained photographs of fish and 
 other mobile forms in the same manner by inclosing the animal to be photographed 
 in a glass globe, which was then immersed in the aquarium at a suitable distance 
 from the lens. The globe served to restrict the movements of the animal. When 
 working in shallow water, he found that the algae which appear everywhere in the 
 submarine landscape were in constant motion whenever there was any movement 
 of the water. It was therefore necessary to restrict operations to those days on 
 which it was perfectly calm. 
 
 In order to obtain photographs at depths at which it was impossible to wade 
 Boutan made use of the diver's outfit. He describes the outfit in detail and the 
 method of using it in a very interesting section of his paper of 1898. The method of 
 procedure was briefly as follows: The boat containing the apparatus to be used 
 (diver's suit, air pumps, and photographic apparatus) was first firmly anchored at the 
 spot selected and held in place by means of cables stretched to the rocks on shore. 
 The photographer then put on the diver's suit and descended to the point selected as 
 the center of operations. He first signaled to an assistant to let down the photo- 
 graphic apparatus, which consisted of the tripod, the box containing the camera, and 
 a weight intended to steady the apparatus. He then sought out the view to be 
 taken and set up the apparatus at his leisure. This accomplished, he opened the 
 shutter of the camera and signaled to the assistant that the exposure was begun. 
 Since it was impossible to use a watch while under water it was necessary that the 
 assistant in the boat above should time the exposure. At the expiration of the 
 time agreed upon the assistant signaled and the photographer closed the shutter. 
 When the weather was good and the sun shining an exposure of ten minutes was 
 necessary with a small diaphragm at a depth of 5 meters. Boutan estimated 
 that at a depth of 10 meters this exposure would need to be more than doubled. 
 
54 
 
 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 -V 
 
 BOUTAX'S SECOND APPARATUS (1896). 
 
 This apparatus (fig. 4) consisted of a metal camera, not inclosed in a box, 
 but intended to be immersed directly in sea water. The sea water could enter 
 and fill the interior of the camera so that it bathed both the front and back faces of 
 the lens as well as the plates. The latter were contained in a holder which could 
 be attached to the camera after it was submerged. Thus the plates could be 
 changed under water without any risk of fogging them. Sea water was found to 
 have little effect on the plates unless its action was prolonged, and this effect could 
 be wholly prevented by using plates that had been varnished. 
 
 The lens used with this apparatus 
 was one intended for use in air, and it 
 was found that good results could not 
 be obtained with it when immersed in 
 water. The success of such an appa- 
 ratus as this must depend on having a 
 lens especially ground for use under 
 water. No lens of this sort existed and 
 to have one calculated and made would 
 have been expensive. For this reason 
 and for others which he mentions 
 Boutan abandoned this apparatus after 
 trying it for a single season. He says, 
 "The principle is certainly good, and, 
 in spite of the failure that I have made 
 in the application of it, the future of 
 submarine photographic apparatus may 
 lie there." 
 
 BOUTAN'S THIRD APPARATUS (1898). 
 
 As a result of the failure of his 
 second, Boutan adopted a third appa- 
 ratus, which was in principle a return 
 to the first. This third apparatus, 
 designed for instantaneous work, consisted of a heavy metal box, shown at the center 
 in figure 5. To it are attached four adjustable legs. The box, which is watertight, 
 contains the objective and the plates. It is itself the camera and does not therefore 
 contain within it a camera, to be lifted out and put back. The lens is a Darlot 
 symmetrical-anastigmatic of excellent quality. At the front is an opening (O) 
 closed by a plate of glass, through which the light enters the lens. There are no 
 finders and consequently no openings closed by glass plates, with the exception 
 of that for the lens. At the top, in front, is a handle by means of which the shutter 
 may be operated. About the center of the box is clamped a band-iron frame with 
 a ring at the top by means of which the box may be attached to a rope for lifting 
 it in and out of the boat. At the back is a cover which may be fastened by means 
 
 FIG. 4. Boutan's second apparatus. B, camera box into 
 which the water could penetrate freely; m, handle control- 
 ling the plate holder; m', handle controlling the shutter; 
 O, objective; V, sight. (Copy of fig. 2 in Boutan, 1898.) 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 
 
 55 
 
 of screws against a rubber packing on the end of the box, so that the joint between 
 cover and box is made water tight. The rubber bag used in the first apparatus 
 seems to have been found unnecessary and is at any rate omitted. At the back 
 of the cover there projects a handle (M) by the manipulation of which the plates 
 may be changed. On the top at V is a sight by means of which the camera may 
 be directed at the desired object. Within the box at the back is a magazine plate 
 holder for six plates. This is represented at the left at C H in figure 9. It is so 
 arranged that when a plate has been exposed it may be made to fall forward by 
 turning the handle shown at M in the central figure. A second plate is at the 
 same time pushed into place by springs. When this has been exposed a second 
 turn of the handle allows the plate to fall and a third plate comes into place. Six 
 plates may thus be exposed without opening the box. On each side of the plate 
 holder are two cleats (gl) . These glide upon two rails on the inside of the box, one 
 on either side, so that 
 the plate holder may be 
 moved back and forth 
 on the rails away from 
 the lens or toward it. 
 By means of a set screw 
 the plate holder may be 
 firmly clamped at any 
 point on the rail. The 
 camera is focused by 
 means of this movement 
 of the plate holder. To 
 prevent reflection of 
 light from the lower 
 side of the surface film 
 of the water into the 
 camera there is pro- 
 vided a semicylindrical 
 shade shown at A B on the right in figure 5. It may be attached to the front of 
 the box above the lens by the arrangement shown at X. 
 
 It is not possible to focus after the box has been closed in order to immerse it. 
 Consequently one of the rails upon which the plate holder moves must be provided 
 with a scale. The divisions on this scale correspond to different distances between 
 the lens and the object to be photographed. When the plate holder is set at a 
 certain division of the scale the camera is in focus for objects at a distance of 4 
 meters; when set at another division for objects at 2 meters. It is therefore 
 necessary to determine before the camera box is closed at what distance the object 
 is to be photographed and to focus by setting the plate holder at the corresponding 
 division on the scale. While the box is immersed this focus cannot be changed. 
 The divisions to be marked on this scale were ob tamed by focusing on submerged 
 objects while the front of the camera was also submerged. This necessitated the 
 use of special devices, which need not be described here. 
 
 FIG. 5. Boutan's third apparatus (1893). A, metal camera box; M, handle control- 
 ling the changing of plates; MO, handle controlling the shutter; O, opening for 
 the lens; P, feet for supporting the apparatus; V, sight; X, points of attachment 
 of the hood AB; CII, magazine holder for six plates; gl, cleats by means of 
 which the holder glides on a rail inside the box; p/, plates; /, pin which holds the 
 front plate in place. (Copy of fig. 3 in Boutan, 1898.) 
 
56 
 
 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 This apparatus, which used plates 18 by 24 cm. (approximately 7 by 9 inches), 
 was so heavy that it required three men to handle it easily in air. On shipboard it 
 was handled by a tackle and swinging boom. It was first lowered into the hold, 
 which could be closed light tight. There the plates were put into the plate holder and 
 this was set at the division of the scale previously decided upon. The box was then 
 closed water-tight by screwing the cover in place. To remove the moisture from 
 the air within the box and thus prevent its condensation on the lens and other parts 
 within, a wide-mouthed bottle containing quick lime was kept in the box during 
 the intervals when it was not immersed. The apparatus was then hoisted from the 
 hold, swung outboard and lowered to the operator, who had meantime descended in 
 the diving suit and selected the point at which the photograph should be made. It 
 was not very difficult for the operator to handle the apparatus w r hen it was sub- 
 
 FIG. 6. Showing Boutan's method of obtaining instantaneous photographs of fish with his third ap- 
 paratus. (Copy of fig. 7 in Boutan, 1898.) 
 
 merged, since it was then buoyed up by the water. It was found easier to move it 
 about when it was suspended by means of a rope to a cask floating at the surface. 
 The method of using the camera for photographing fish is shown in figure 6. 
 The camera, previously set for objects at a distance of 2.5 meters, was placed on 
 a sand bottom at a depth of 3 meters. Here it was either allowed to rest on 
 the bottom on the legs attached to it or was supported above the bottom on a 
 heavy, four-legged iron frame. The camera rested on a platform within this frame 
 and the platform might be so adjusted that the camera could be set at various 
 heights and pointed at various angles up or down. At a distance of 2.8 meters 
 from it was set up obliquely a large white screen of painted canvas stretched on an 
 iron frame provided with feet. This screen served as a background for the fish. 
 To attract the fish the operator then placed in front of the screen at a distance of 
 about two meters a bait of crushed sea-urchins and annelids. He then pointed the 
 camera by means of the sight on top and waited until the fish, attracted by the 
 bait, were in such a position as to be in focus, when by means of the handle at the 
 
U N \ V . 
 
 PHOTOGRAPHY OF AQUATIC ANIMALS, 
 
 57 
 
 front he made the exposure. The plate was then changed and several exposures 
 made in succession. The screen was useful as affording a contrasting background 
 but was not considered necessary, since very clear negatives were obtained of fish 
 viewed against the sand or ooze bottom. One of the photographs of fish taken 
 against a screen background is reproduced by heliogravure in Boutan's memoir of 
 1898. Though the fish were in motion, the outlines of most of them appear sharp 
 against the screen, evidence that the picture was instantaneous. The fish are, 
 however, unfortunately almost wholly lacking in detail. The time of the exposure 
 is not stated, but it was clearly too short to give detail in the shadows. 
 
 In figure 7 is shown a method adopted by Boutan for operating the camera 
 from a boat by means of a string. In this case the apparatus was first placed in 
 
 FIG. 7. Showing Boutan's method of operating his third apparatus from a boat by means 
 of a string. A diver is being photographed. (Copy of fig. 8 in Boutan, 1898.) 
 
 position by the diver, who then withdrew to the distance for which the camera was 
 focused. The operator, who could observe the procedure from the boat, then pulled 
 the string. The resulting picture, which is reproduced in Boutan (1898) , is excellent. 
 Subsequently exposures were made from the surface by using a shutter controlled 
 by an electro-magnet. 
 
 BOUTAN'S METHODS OF ARTIFICIAL ILLUMINATION. 
 
 Besides his camera, Boutan (1893) describes an apparatus for using a mag- 
 nesium flash-light beneath the surface of the water. He succeeded subsequently 
 in taking good instantaneous pictures at a depth of 3 meters without artificial 
 
58 
 
 BULLETIN OF THE BUKEATJ OF FISHERIES. 
 
 light, and estimated that in good weather it would be possible to do this at depths 
 of 7 or 8 meters. 
 
 Although his flash-light apparatus proved to be unnecessary in shallow water 
 and was subsequently abandoned as cumbersome and dangerous, it merits a 
 word of description. His figure of it is reproduced in figure 8. In its final form it 
 consisted of a cask of about 200 liters capacity closed at both ends, but with 
 the lower end perforated by holes to permit the entrance of sea water. A bell jar 
 of 5 or 6 liters capacity is held tightly against the upper end of the cask by means 
 of the adjustable frame shown in the figure. The cavity of the jar communicates 
 freely through many openings with that of the cask, and both are filled with air. 
 
 Within the bell jar is an alcohol lamp, and at the 
 side of this is a metal reservoir (not shown in the 
 figure), covered with asbestos and filled with mag- 
 nesium powder. One end of a metal tube opens 
 opposite the middle of the flame of the alcohol 
 lamp (shown lighted in the figure) and communi- 
 cates freely with the reservoir above. The other 
 end of the tube extends into the cask, and is there 
 connected to a rubber tube which extends through 
 the side of the cask (at C in fig. 8) and ends in 
 a large rubber bulb. To use the apparatus, the 
 reservoir is filled with magnesium powder and 
 the alcohol lamp lighted, then the bell jar is 
 fastened in place and the cask, heavily weighted 
 at the bottom, is lowered into the water and set 
 wherever needed. The air in the bell jar and cask 
 is enough to keep the alcohol lamp burning for 
 some time. To produce the flash it is merely 
 necessary to press the bulb, when the magnesium 
 powder, which has fallen from the reservoir into 
 the tube, is blown against the flame from the end 
 of the tube and ignited. This operation may be 
 repeated as long as the lamp remains burning and 
 the reservoir contains magnesium. It is of course 
 necessary to operate the shutter of the camera 
 simultaneously with the flash. 
 Boutan (1900) describes and illustrates another illuminating apparatus which 
 consists of two powerful arc lamps inclosed in water-tight jackets of heavy metal, 
 designed to withstand the pressure of the water at a depth of 50 meters or more. 
 Each jacket was pierced by an opening into which was fitted a condensing lens, 
 by which the emerging light was concentrated upon the object to be photographed. 
 The two lamps were rigidly attached to the camera support and were supplied, 
 through a cable, with current from storage batteries on board the boat. The 
 same cable carried also an insulated wire through which an electro-magnet 
 actuating the shutter of the camera could b'e controlled. The camera with lamps 
 attached was lowered into the water. When the camera was on the bottom the 
 lamp circuit was closed by means of a switch on board the boat, and when it was 
 
 FIG. 8. Boutan's apparatus for using a mag- 
 nesium flash-light under water. The reser- 
 voir for the magnesium powder, the rubber 
 bulb, and th weights used to steady the ap- 
 paratus are not shown in the figure. (Copy 
 of fig. 3 in Boutan, 1893.) 
 
PHOTOGRAPHY OF AQUATIC AWIMAU8, 59 
 
 seen that the lamps were working, the shutter was operated from the boat. In 
 this way good photographs of gorgonias were obtained at night at a depth of 6 
 meters, with an exposure of five seconds. It is not necessary that the diver should 
 descend to place the lamp in position. The same apparatus was worked successfully 
 at a depth of 50 meters, in this case the apparatus not being allowed to rest on the 
 bottom, but being held suspended from a cable at some distance from the bottom. 
 The object photographed was a canvas screen rigidly attached by rods to the camera 
 support at such a distance from the lens as to be sharply focused. When the 
 apparatus was brought to the surface it was found that one of the lamps had failed 
 to withstand the pressure so that its jacket was filled with water. With lamps 
 and camera constructed to withstand the pressure at great depths, Boutan believes 
 that an apparatus of this sort may be used at depths to which light does not 
 penetrate. The apparatus may of course be used by a diver at depths of 40 meters 
 or less, and the camera may then be directed at any desired object; but at greater 
 depths a diver can not work, and the apparatus must then of course be let down at 
 random, to photograph only what chances to be in the range of its lens. 
 
 Boutan's work has the great merit of having demonstrated that it is possible 
 at a depth of 3 meters to obtain good instantaneous pictures by the light of the 
 sun and without the use of artificial light. He showed further that his apparatus 
 with electric illumination could be immersed and operated from outside the 
 water at depths as great as 50 meters. For work at great depths or by artificial 
 light no better apparatus is known. The faults of it, for work in shallow water or 
 at any depth to which a diver can descend, are (1) its great bulk and weight, and (2) 
 the fact that it can not be focused under water. It can not be carried about freely, 
 and for use it must be set on the bottom at a known distance from the object to be 
 photographed and must then be sighted at that object. It is unfortunate that 
 for work in shallow water Boutan did not make use of the principle of the twin 
 camera or the reflecting camera, for by using either of these devices he could have 
 made an apparatus that was portable and that could have been focused under water. 
 He could thus have carried his camera about as one carries detective cameras and 
 could have photographed submarine objects either while wading with his head 
 above water or hi moderate depths while on the bottom in a diver's suit. 
 
 BRISTOL'S SUBAQUATIC CAMERA. 
 
 That such a method is feasible and that it may yield better results than 
 those obtained by Boutan was suspected as early as 1898 by Prof. C. L. Bristol, 
 who immediately began work on a submarine photographic apparatus. Nothing 
 has as yet been published concerning this apparatus, and the details of its con- 
 struction are quite unknown to me. Professor Bristol kindly permits me, however, 
 to make the following quotation from a letter to me on the subject: "From the 
 first I have used a water- tight camera capable of submersion hi from 10 to 15 
 fathoms, mounted on a tripod with a universal motion, arranged so as to show the 
 picture on the ground glass as well as to focus the lens and make the exposure. 
 Moreover, a magazine attachment permits me to carry down several plates and to 
 change them after each exposure while under water. After several seasons' efforts 
 the apparatus is now very efficient and has produced excellent results. I am not 
 yet ready to publish a detailed account." 
 
60 
 
 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 A NEW SUBAQUATIC APPARATUS. 
 
 When a camera for subaquatic use is made after the ordinary type the box 
 must be securely closed before submerging it in order to protect the lens and the 
 plates from the action of the water. While the camera is under water it is not 
 possible to remove the plates or plate holder in order to substitute a ground glass 
 for them. It is therefore impossible to focus, and the camera must be adjusted to 
 the desired focus before immersing it. This was the method adopted by Boutan 
 in his third apparatus. It would be possible to construct a camera that might be 
 focused under water by means of a focusing scale such as is provided in those hand 
 cameras arranged to be focused without the use of a ground glass, the operator 
 estimating the distance of the object and then setting the camera for a corresponding 
 
 division on the focusing scale. This 
 method is of value for more distant ob- 
 jects and with rather slow lenses of 
 great focal depth. When very rapid 
 lenses are focused on near objects only 
 those objects are in focus that lie nearly 
 in one plane. Thus a very accurate ad- 
 justment of the camera is necessary in 
 order to bring any near obj ect into sharp 
 focus, and this is not possible when the 
 distance of the obj ect must be estimated 
 and the focusing accomplished by means 
 of a scale. In subaquatic photography 
 the objects to be photographed are all 
 near and if instantaneous work is to be 
 done the lens must be very rapid. It 
 is therefore important to be able to focus 
 accurately on the ground glass under 
 water, and this might be accomplished 
 by using two identical cameras (twin 
 camera) united so as to form one instru- 
 ment. One of these contains the plates 
 and has a lens provided with a shutter. 
 The other camera carries the ground glass. The same focusing mechanism operates 
 both cameras, so that when a sharp image is formed on the ground glass of the one an 
 identical image strikes the sensitive plate in the other when the shutter is operated. 
 One of the cameras serves merely as a focusing finder of full size. A camera of this 
 type properly constructed of metal could undoubtedly be used successfully under water, 
 though it has the disadvantage of being unnecessarily cumbersome and expensive. 
 
 THE CAMERA. 
 
 All of the advantages of the twin camera are to be had by using a reflecting 
 camera, which is at the same time both lighter and less expensive. The principle 
 of the reflecting camera is shown in figure 9, which represents diagrammatically 
 
 FIG. 9. A reflecting camera shown in section, with magazine 
 plate holder attached, gl, ground glass; h h', hood; Z,lens; m, 
 mirror in position during focusing; m', mirror, showing position 
 during exposure; p, sensitive plate; r and r', rollers of focal 
 plane shutter; s, the shutter; si, slot in shutter; x, hinge on 
 which mirror turns; y y y', ray of light traversing the lens and 
 reflected from the mirror to the ground glass. 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 61 
 
 such a camera in longitudinal section. The ground glass (gl) is placed, not at the 
 back of the camera, as is usual, but in the top. The operator, holding the camera in 
 front of him, looks in the direction indicated by the upper arrow, at the ground glass 
 through the hood (h Ji'), which takes the place of a focusing cloth. The ulterior of 
 the camera contains a mirror (m), which extends from beneath the back edge of the 
 ground glass downward and forward at an angle of 45. The mirror is hinged at x 
 to the top of the camera. When 'it is in the position shown at m in the figure the 
 space between the back of the mirror and the back of the camera is quite dark. 
 Light entering through the lens is reflected by the mirror and strikes the ground 
 glass, as shown by the line y y y' . The image as seen on the ground glass by the 
 operator looking down through the hood is, on account of the action of the mirror, 
 an erect image, not an inverted image such as one sees on the ground glass in the 
 back of an ordinary camera. It is also an image of the full size permitted by the 
 plate and the lens, not a reduced image such as one sees in a finder. The shutter 
 (s) is a focal plane shutter situated at the back of the camera just in front of the 
 plate (p). Such a shutter is essentially a roller curtain of black cloth with a slot (si) 
 across it at one point. The width of the slot may be regulated. The shutter is 
 wound upon an upper roller (r) until the slot is upon the roller. The exposure is 
 made by causing the curtain to unwind from the upper roller (r) and wind upon the 
 lower roller (/) so that the slot passes very rapidly across the face of the plate. 
 The length of the exposure depends on the width of the slot and the rate at which it 
 moves. The rate may be varied by changing the tension of the spring which 
 actuates the lower roller. The operator holds the camera in front of him with both 
 hands while he looks down at the ground glass through the opening in the hood. 
 With one hand he focuses. When the object appears in sharp focus and hi the 
 desired position on the ground glass, he presses a button with the other hand. 
 This causes the mirror to swing on its hinge to the position shown by the dotted out- 
 line m' beneath the ground glass. In this position the mirror excludes light which 
 might otherwise enter the camera through the ground glass. At the same time the 
 change in position of the mirror permits the light, which was before reflected to 
 the ground glass, to fall upon the plate. The adjustment is such that an image 
 which is in sharp focus on the ground glass will be in sharp focus on the plate when 
 the mirror changes position. The image does not actually strike the plate so long 
 as the shutter is wound upon either roller. Before the instrument is to be used the 
 shutter is wound on the upper roller. When the mirror in swinging upward reaches 
 the position m' the shutter is released from the upper roller and taken up on the 
 lower roller. As the slot passes across the plate from above downward, the image 
 falls through the slot onto the plate in successive strips corresponding to the width 
 of the slot. 
 
 The advantages of this form of camera are the folio wing : 
 
 1. The operator sees a full sized, erect image on the ground glass, while at the 
 same time the sensitive plate is in position for exposure. 
 
 2. He is able to focus and to regulate the position of the image on the ground 
 glass up to the instant of exposure. 
 
 3. Much more rapid exposures may be made with the focal plane shutter than 
 with the ordinary diaphragm shutter. The diaphragm shutter occupies a considerable 
 
62 BULLETIN OF THE BUREAU _ OF FISHERIES. 
 
 time in opening and closing, and during the period of operation prevents the light 
 from passing through the full opening of the lens. If the time from the instant 
 a diaphragm shutter begins to open until it is closed again is one one-hunredthd 
 of a second, then a considerable part of this time (usually about 40 per cent) is 
 occupied by the opening and closing. The shutter is then wide open and the lens 
 working at its full opening during only a fraction of the one one-hundredth of a second. 
 With the focal plane shutter, on the other hand, if the slot requires a hundredth 
 of a second to pass a given point on the plate, the lens may be wide open during the 
 whole of that time, so that all the light that the lens is capable of passing reaches 
 the plate during the whole of the exposure. For this reason much more rapid 
 exposures may be made with the focal plane shutter than with the diaphragm shutter. 
 Various forms of reflecting camera are in the market, and it is possible to 
 obtain a magazine plate holder, which carries 12 plates, arranged to be changed 
 without removing the plate holder from the camera or inserting the dark slide. 
 Such a camera, with the magazine holder, is shown diagrammatically in section in 
 figure 9. It is surprising that Boutan, when he was seeking some means of focusing 
 his camera under water, did not make use of the idea of the reflecting camera; for 
 by merely inclosing such a camera in a water-tight metal box and arranging it to 
 be operated from outside the box, he would have had a portable apparatus capable 
 of being manipulated under water almost as readily as on land. A reflecting 
 camera was manufactured in New York as early as 1886, and was advertised at 
 that time and represented by a Paris agent. 
 
 THE WATER-TIGHT BOX. 
 
 A 5 by 7 camera of the type just described, with a magazine holder for 12 plates, 
 was used by the writer to obtain submarine photographs at Tortugas, Fla., during 
 the season of 1907. The box (fig. 2, pi. v) to contain the camera was made of gal- 
 vanized iron by a tinsmith. It measures about 17 inches long, 9 inches high, and 10 
 inches wide. The front is closed by a square of plate glass cemented with aquarium 
 cement into a groove formed in the metal. At the top is an opening large enough 
 to permit the camera to pass, bottom first, into the box. To the outside of the rim 
 of this opening is soldered half-inch square brass tubing jointed at the corners into 
 a rectangular frame. The upper surface of this frame is made as smooth and as 
 nearly plane as possible. Eight brass screw-bolts are soldered into holes drilled 
 through this frame. They occupy the positions shown in the figure and the threaded 
 end of each projects about three-quarters of an inch above the frame. The cover 
 consists of a flat sheet of metal bordered by a frame of brass identical with that on 
 the box. This frame is perforated by eight openings through which the screw-bolts 
 pass. From the cover there arises an irregular truncated pyramid of galvanized iron, 
 which incloses the hood of the camera. At the top this is closed by a piece of plate 
 glass. By means of wing nuts on the screw-bolts the cover may be tightly clamped 
 to the box, against an intervening gasket of rubber. 
 
 On the right hand side of the box is a large milled head of brass from which 
 a brass stem passes to the interior through a stuffing box, which prevents the 
 entrance of the water along the stem. At its inner end the stem terminates in a 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 63 
 
 two-pronged fork. The stem may be pulled in and out in the stuffing box through 
 a distance of about three-quarters of an inch. When the stem is pushed in, the 
 prongs of the fork engage hi two holes drilled hi the focusing head of the camera. 
 By turning the milled head on the outside of the box the camera may then be 
 focused. On the opposite side of the box is a second but smaller brass head from 
 which a stem passes through a stuffing box to the interior of the box, and termi- 
 nates in a flat disk. The disk lies opposite the release pin of the camera by which 
 the mirror and shutter are set in motion. A light spiral spring wound about the 
 stem between the outer head and the stuffing box keeps the stem thrust outward 
 to its full extent. Pressure on the outer head causes the metal disk to strike the 
 release pin so as to make the exposure. 
 
 In order to use the box, it is necessary to attach to it a weight heavy enough 
 to submerge all but about the upper 6 inches of the hood. In the experimental 
 apparatus used this weight was made by folding sheet lead to form a flat mass of 
 the dimensions of the bottom of the box. The weight (not shown hi the figure) 
 was made slightly wedge shaped lengthwise and was attached to the bottom of 
 the camera by wires passing beneath it and soldered at their ends to the sides of the 
 box. As the camera would, in use, usually be pointed slightly downward, the 
 thicker end of the weight was placed in front, so that the box floated with its front 
 end somewhat lower than its back end. 
 
 USIN'G THE APPARATUS. 
 
 The apparatus was used hi the following manner: The magazine plate holder 
 containing twelve plates was attached to the camera, the mirror depressed, the 
 shutter set at the desired speed and width of slot, and wound. The dark slide was 
 then drawn from the magazine holder, and the camera, thus made ready for an 
 exposure in air, was placed in the box. Metal cleats soldered to the bottom of the 
 box brought it always to the same position. The head on the right of the box 
 was then pushed in until the fork engaged in the holes in the focusing head of the 
 camera. The top was then put on the box and clamped down by the wing nuts as 
 firmly as possible. The apparatus thus made ready was, when in air, as heavy a 
 load as one man could conveniently carry. It was carried to a boat or, if it was to 
 be operated near shore, to the shore. In working with the help of a boat the 
 operator wades on or near the coral reef with his head and shoulders above the water. 
 The boat, with an attendant on board, is anchored near. The operator, with the 
 help of a water glass, now seeks a favorable place for operations. As he moves about 
 the reef, the fish at first seek shelter in the dark recesses of the coral rock, but if he 
 selects a favorable place and remains quiet they soon reappear. They are at 
 first wary, but soon grow bolder and after half an hour or so pay but little atten- 
 tion to him. There is a great difference in wariness among different species of fish. 
 At first only one or two species appear, demoiselles and slippery-dicks usually, then 
 the number of species gradually increases until the shyest butterfly-fish and parrots 
 come within 6 or 8 feet of the operator. He then has the camera passed to 
 him from the boat. It floats with the upper part of the hood protruding and 
 (fig. 1 , pi. v) may be easily turned toward any point on the horizon or even tilted so as 
 
64 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 to be pointed at a considerable angle upward or downward. The operator has now 
 merely to direct the camera at the fish, while he focuses with his right hand. He 
 must often wait some time before the fish come to the point selected or assume 
 the desired attitude. Often they may be enticed by throwing in a bait of crushed 
 sea urchins or pieces of crawfish. They are in constant motion so that he must 
 as constantly focus. He often misses a long-awaited opportunity because the fish 
 moves on or takes a wrong attitude before he has had time to focus sharply; but 
 when the favorable time comes he presses the release stem and the exposure is made. 
 
 The apparatus must then be lifted into the boat, the cover removed from the 
 box, and the camera taken out in order to reset the shutter and change the plate. 
 It is best that all this be done by the attendant who remains in the boat, as the 
 operator is thus left free to watch the fish, while at the same time the fish are not 
 unduly frightened by the sudden movements that he would make in lifting the 
 camera. With care, however, one person may do all the work necessary. He 
 may anchor the boat near, pull it to him by means of a line, lift in the camera, and 
 make all the necessary adjustments while he himself remains in the water. If the 
 work is done near shore, the camera may be carried to shore after each exposure. 
 In that case an assistant is very desirable, since the return of the operator after 
 each absence disturbs the fish. Moreover, when near shore he is moving over the 
 rock or sand bottom, not over the clean upper surface of the reef, and every con- 
 siderable movement stirs up the bottom sediment so that some time must pass 
 before the water is again clear enough to permit an exposure to be made. If an 
 assistant is available, he may stand at a considerable distance from the operator, 
 who sends the camera box to him through the water by a quick shove. The assistant, 
 after he has carried it ashore and readjusted it, returns it in the same way. 
 
 The opening of the box after each exposure occupies some little time, and 
 during this time favorable opportunities to make exposures are often lost. It 
 would be better if a mechanism were provided by which the plates might be changed 
 without opening the box, which would then remain in the water until twelve expo- 
 sures had been made. Nevertheless it is possible with the apparatus described to 
 make twelve exposures on coral-reef fish in about two hours, including the lifting 
 of the box from the water between exposures and opening it to change plates. 
 Any form of reflecting camera may be used and any form of plate holder. Films 
 may also be used in rolls or packs. In addition to the reflecting camera the operator 
 needs only a metal box of the structure described and of a form suited to his camera. 
 This may be made by any good tinsmith at a cost of a few dollars. 
 
 A camera of this type inclosed in a suitable box may be held in the hand while 
 in use, or it may be set upon a tripod of heavy iron, such as is shown in figure 4. 
 Such a tripod would best have a top of the form shown in figure 2, but made of heavy 
 iron instead of wood. The operator may descend in a diving suit, as Boutan did, 
 and use the camera at the bottom in deep water either while holding it in the hand 
 or while it is supported on a tripod. There should be no difficulty in focusing 
 while looking through the plate-glass window of a diver's casque. For work on the 
 coral reefs of the Tortugas, however, the writer has found that everything may be 
 done from the surface, so that a diver's suit is quite unnecessary. He is told that 
 similar conditions exist at the Bermudas. From his own experience in fresh water 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 65 
 
 he is inclined to believe that probably all the photographic work that it is desirable 
 to do there may be done without the use of a diver's suit. The occasions on which 
 such a suit is really necessary for work in either fresh or salt water are probably 
 extremely rare. 
 
 If the objects to be photographed are motionless, or nearly so, time exposures 
 may be made with this apparatus by suitably adjusting the camera before placing 
 it in the box. For this use it is desirable to add to the box a third rod working 
 through a stuffing box and so placed that by means of it the shutter may be released 
 independently of the mirror. 
 
 Two photographs made by the method here described are reproduced on plate 
 ii. In figure 1, plate i, a butterfly-fish (Chaetodon ca pi stratus) with a stripe through 
 the eye and an eye-like spot on the tail is seen over a flat expanse of coral ( Meandrina) 
 and at the base of a large, branching gorgonian. The photograph was taken while 
 the fish was in rapid movement. The expanded polyps may be seen on the gorgo- 
 nian just above the fish and elsewhere. Figure 2, plate n, shows a group of parrot 
 fishes, of at least three species, and several surgeons against a background of branch- 
 ing gorgonians on a ledge of rock. Near the center is a blue and yellow striped 
 grunt, Hsemulon Jlavolineatum. At the left of this is a blue parrot-fish, CaUyodon 
 cwuleus. At the right of the grunt is a green parrot-fish, CaUyodon vetula, about 
 18 inches long. Beneath the green parrot is a mottled parrot-fish (Sparisoma?}. 
 Above the grunt is a second mottled parrot and to the left of this a third. At 
 the extreme left are two surgeons, Ilepatus Jiepatus: a third is seen below the green 
 parrot. Above the green parrot, in the background, is a purple sea fan, RJiipi- 
 doglossa. In most of the fish the details of the markings and the outlines of the 
 scales are clearly seen. 
 
 These photographs were taken in water about 4 feet deep with a Goerz II. B. 
 lens at a speed of f 5. The exposure was 3*5 second with Seeds P. orthochro- 
 matic plate and a no. 3 graphic color screen. The plates were fully timed and 
 were developed rapidly with a strong pyro developer. 
 
 The apparatus used by the writer was experimental only and was meant 
 for temporary use. It is easy to suggest improvements, the greatest of which 
 would be a magazine plate holder for at least twelve plates and capable of being 
 operated from outside the box which incloses the camera. There appears to be no 
 such holder on the market. Magazine holders provided with a bag can not be 
 used even though the leather bag of the plate holder be covered with a rubber bag 
 so attached to the box inclosing the camera that the water can not enter, for the 
 pressure of the water is such that even when the box is but partly immersed the 
 rubber bag is forced into the box through the opening to which it is attached and 
 the holder can not then be manipulated. This difficulty would be increased if an 
 attempt were made to use the apparatus at a greater depth. What is needed is a 
 magazine plate holder that presents a rigid exterior everywhere and that may be 
 operated from the outside of the box by means of rods passing to the inside through 
 stuffing boxes. 
 
 The box can be improved by reducing to its lowest limit the number of screws 
 used to fasten the cover, for if but one or two screws had to be loosened to open the 
 box much time would be saved in changing plates. 
 
 B. B. F. 19075 
 
66 BULLETIN OF THE BUKEAU OF FISHERIES. 
 
 A part of the weight attached to the bottom of the box should be movable, 
 so that it could be fastened either toward the front or toward the back. In this way 
 the box could be made to float with the lens pointed at a considerable angle toward 
 the bottom or toward the surface of the water. The operator would then be spared 
 the very considerable effort necessary to hold the box in position when the lens 
 is directed much above or below the plane in which the box floats. 
 
 The purpose of the writer has been to utilize an ordinary reflecting camera 
 for subaquatic work by inclosing it in a suitable water-tight box without in any way 
 lessening its availability for use in air when removed from the box. For use 
 exclusively in water it would be best to design a reflecting camera that could be 
 immersed directly in water without first inclosing it in a box. Such a camera 
 would have to be of metal, water-tight, and would need to have the lens covered 
 by a plate of glass. It would need to have only a small opening at the back on 
 one side for inserting and removing the plates. Such an opening could probably 
 be readily closed by a cover held in place by one or two screws. A camera of this 
 sort, if made rigid enough to withstand the pressure of the water at even moderate 
 depths, would be too heavy for convenient use in air. It would have the advan- 
 tage of simplicity and increased ease of manipulation. 
 
 SOME LIMITATIONS OF SUBAQUATIC PHOTOGRAPHY. 
 
 Turbidity of the water sets a limit to subaquatic photography very much as 
 fog or rain or partial darkness restricts photography in air. The water must be 
 clear that is, apparently free from particles in suspension. If instantaneous 
 work is to be attempted the water must be free from the reddish color that often 
 tinges fresh-water lakes and streams, for the tinge of red or yellow acts as a color 
 screen and greatly lengthens the time necessary for the exposure. 
 
 When one looks from the air into the ocean water at the Tortugas or Bermudas, 
 or into the fresh water of some of our northern lakes, it appears to be as clear as 
 the air itself. When the surface is undisturbed, objects on the bottom at depths 
 of 10 to 20 feet appear with as much clearness as though seen through air alone. 
 The impression is created that such water is actually as clear as air, and that the 
 water would offer no .more obstruction to the vision of one beneath it than air 
 itself. To test this impression the writer constructed a reflecting water glass 
 somewhat like a reflecting camera without the lens. It was a metal tube 2 feet 
 long, and contained two parallel mirrors, set at an angle of 45 with its long axis, 
 and placed one at each end. By putting one end of this with its mirror beneath 
 the surface and looking into the mirror at the other end, he obtained a view of the 
 subaquatic landscape such as a diver obtains when he looks about him through 
 the glass window in his casque. It is surprising to find how limited is the range 
 of one's vision under these circumstances. Even in the clear sea water about 
 tropical islands objects at a distance of 20 feet begin to appear indistinct, and 
 beyond that distance they fade into a bluish haze which constitutes the back- 
 ground. This haze has not the effect of fog or smoke or twilight. It is as though 
 the near distance were limited on all sides by walls of bluish translucent quartz 
 which merged into the near water. From these walls the fish emerge and grow 
 
PHOTOGRAPHY OF AQUATIC ANIMALS. 67 
 
 rapidly more distinct as they approach. Into them they vanish suddenly as they 
 recede. 
 
 Subaquatic photographs show the same lack of distance that so impresses the 
 eye. Thus in the photographs shown on plate n the distance appears indistinct, 
 partly because the objects in it are out of focus, but chiefly because they are enveloped 
 in the bluish translucence mentioned above. It is therefore impossible under water 
 to photograph objects at any considerable distance. To the photographer who 
 is unfamiliar with the aspect of the subaquatic landscape this lack of distance in 
 photographs of it seems a defect. But to the artist or naturalist who has seen things 
 as they look to one beneath the water it is really a merit, since it shows these things 
 as they are. 
 
 The source of this lack of distance is probably double. It is due in part to the 
 fact that even the clearest water contains very many bodies in suspension, living 
 organisms, and inorganic and organic particles. These, like dust in the atmosphere, 
 interfere with distance vision. It is due also in part to the reflection of the light 
 from the surface of the water. Light which has entered the water from above 
 strikes upon and illuminates various bodies beneath the surface. From these a part 
 of it is reflected to the surface of the water again. If it strikes the surface at an 
 angle of more than 48 35' with the vertical it is totally reflected and passes again 
 into the water. Here it again strikes some submerged body and is again in part 
 reflected to the surface and here again in part re-reflected- Thus shallow water is 
 traversed in every direction by beams of light which intercross at every angle. 
 These illuminate the opaque particles floating in the water and are deflected bv 
 reflection. They are also deflected by refraction through the more transparent 
 organisms. In this way probably is produced the background of bluish-white 
 opalescence which characterizes the subaquatic landscape. To one who knows 
 that landscape, the background, hiding many mysteries, adds to it character and 
 beauty. A photograph that failed to show it would be lacking in character. Boutan 
 (1893), who discusses this subject, made use of a blue color screen and believed that 
 he obtained greater distance in his subaquatic pictures by this means. In his more 
 recent work (1900, p. 283) he abandoned the use of the color screen. He obtained 
 clear pictures of near objects by using a shade above the lens, as already described. 
 Boutan appears never to have obtained clear pictures of more distant objects. The 
 writer has made use of an ordinary yellow color screen (graphic no. 3) but is unable 
 to say with certainty that it adds anything to the distance in his pictures. The 
 subject needs further study. 
 
 A second characteristic of the subaquatic photographs that strikes the photog- 
 raphers unpleasantly is their flatness. Objects of all sorts appear lacking in thick- 
 ness or rotundity and do not cast abrupt or heavy shadows. This peculiarity the 
 writer believes to be due to the reflection of light from submerged objects into the 
 water at the water's surface. Light thus reflected on the subaquatic object from 
 the bottom beneath and from the surface above and at all angles takes out of it 
 much of its roundness. It takes out the shadows very much as a photographer in 
 his studio may take them out by a suitable adjustment of reflecting screens. Along 
 with this flatness of the individual objects in the subaquatic photograph there is 
 abundance of contrast between different parts, as may be seen in plate I. 
 
68 BULLETIN OF THE BUREAU OF FISHERIES. 
 
 This lack of distance and this flatness combined with contrast, so character- 
 istic of the subaquatic photograph, are not real defects. They are rather truthful 
 representations of the conditions that actually obtain. To the photographer 
 accustomed only to photographs made on land they appear to be defects. To one 
 who knows the subaquatic landscape they are, from the artistic standpoint, sources 
 of beauty. From the scientific point of view they undoubtedly place limitations on 
 subaquatic photography. 
 
 LITERATURE CITED. 
 
 BOUTAN, L. 
 
 1893. Memoirs sur la photographic sous-marine. Archives de Zoologie expeYimentale et gonerale, 
 
 ser. 3, t. i, p. 280-324, pi. xvm and 4 fig. 
 1898. L'instantane dans la photographic sous- marine. Comptes rendus de 1' Academic des 
 
 Sciences, Paris, t. cxxvn, p. 731-733 (Novembre). 
 1898a. L'instante dans la photographic sous-marine. Archives de Zoologie experimentale et 
 
 generale, ser. 3, t. vi, p. 299-330, pi. xx-xxm, 8 fig. 
 1900. La photographic sous-marine et les progres de la photographic. Paris, 1900, 332 p., 52 fig., 
 
 12 pi. 
 FABRE-DOMERGUE. 
 
 1898. Photographie d'aquarium. Photo-Gazette, vol. vn (8). 
 JORDAN, D. S., and EVERMANN, B. W. 
 
 1902. American food and game fishes. 573 p., illus. New York. (Contains many photographs 
 
 from life by A. Radclyffe Dugmore.) 
 REIGHARD, JACOB. 
 
 1903. The natural history of Amia calva Linnaeus. Mark Anniversary Volume, p. 57-109, pi. vu. 
 
 (Plate reproduced by lithography from colored photographs of Amia.) 
 RUDATJX, L. 
 
 1908. La photographie a travers Feau. La Nature, no. 1824, 9 Mai, 1908, p. 360-363. (Transla- 
 tion in Literary Digest of June 13, 1908.) 
 SAVILLE-KENT, W. 
 
 1893. The Great Barrier Reef of Australia. Its products and potentialities. London, p. i-xvm-|- 
 
 1-387. Photo-mesotype pi. I-XLVIII, chromo pi. i-xvi. 
 SHUFELDT, R. W. 
 
 1898. The camera and the aquarium. Photo Era, vol^n, p. 147-150, 3 fig. 
 
 1899. Experiments in photography of live fishes. Bulletin U. S. Fish Commission, vol. xix, 1899, 
 
 p. 1-5, pi. 1-9. 
 
Bui. U. S. B. F. 1907. 
 
 PLATE III. 
 
 - - 
 
 - +&*&!: ".' -V-i 
 
 FIG. 1 . PHOTOGRAPH OF THE NEST OF A SMALL-MOUTHED BLACK BASS i MICROPTERUS DOLOMIEUj 
 TAKEN WITH THE AID OF A SCREEN, THE CAMERA ABOVE WATER. 
 
 FIG. 2. BROOK LAMPREYS i LAMPETRA WILDERI) ON THE NEST, PHOTOGRAPHED THROUGH THE WATER GLASS SHOWN IN 
 FIGURE 2, PLATE IV, IN ABOUT 8 INCHES OF RUNNING WATER. 
 
Bui. U. S. B. F. 1907. 
 
 PLATE IV. 
 
 FIG. I. WATER GLASS DESIGNED BY THE WRITER TO BE USED FOR OBSERVATION OR 
 PHOTOGRAPHY OF OBJECTS UNDER WATER. 
 
 The cover is shown at the left. 
 
 FIG. 2. TWO-FOOT WATER GLASS SUPPORTED ON FOUR LEGS AND PROVIDED 
 WITH SCREEN, AS USED FOR STUDYING AND PHOTOGRAPHING LAMPREYS 
 (LAMPETRA WILDERI). 
 
Bui. U. S. B. F. 1907. 
 
 PLATE V. 
 
 FIG. I. PHOTOGRAPH SHOWING THE METHOD OF USING THE REFLECTING CAMERA WHEN 
 INCLOSED IN THE WATER-TIGHT BOX FOR SUBAQUATIC WORK. 
 
 The upper part of the box covering the ho<Kl rises above the surface, while the lower part, containing 
 the camera proper. i> under water. The operator is looking into the hod through the plate glass 
 in the top of the box. With his right hand he focuses : with his left makes the exposure. 
 
 FIG. 2. GALVANIZED-IRON BOX WITH PLATE-GLASS FRONT, DESIGNED BY THE WRITER TO 
 CONTAIN A 5 BY 7 REFLECTING CAMERA WHEN USED UNDER WATER. 
 
 For description see text, page 6'J. 
 
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 WILL BE ASSESSED FOR FAILURE TO RETURN 
 THIS BOOK ON THE DATE DUE. THE PENALTY 
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 DAY AND TO $1.OO ON THE SEVENTH DAY 
 OVERDUE. 
 
 FR 19 1Q.37 
 
 
 FEB 5 1947 
 
 
 .... ft 4QR5 
 
 
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 MAY 2 6 1955 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 LD 21-100m-8,'34