Slow Motion Picture Research Articles

Crash tests to evaluate the design of temporary traffic control devices for increased safety of cyclists at road works

In Sweden there is an on-going process to formulate a national standard regulating the design of temporary traffic control devices used on pedestrian and bicycle paths. This paper presents results from simulated single-bicycle crashes with the purpose to create an understanding of how different features of such devices affect the risk of injuries among cyclists. A Hybrid II 50th percentile crash test dummy was placed in the saddle of a bicycle and crash tests, usually at 25 km/h, were performed. Eleven different types of road equipment were included, and different crash angles were applied, in a total of over 50 crash tests. The road equipment represented temporary traffic control devices of various kind commonly used in Sweden, but also some specifically designed for cyclists. The tests were documented with several video cameras at different angles. Slow motion pictures were analyzed with focus on mechanisms during impact and the following motion of the bicycle and the dummy. Observations regarding “body parts” in contact with the road equipment were of particular interest highlighting design features of importance such as height, smoothness of surfaces and energy-absorbing capacity. The tests show that all bicycle crashes into road equipment can cause injuries and thus the use of work zone material on bicycle paths should be avoided, if possible. Safety barriers designated to prevent cyclists from falling into a shaft must be high enough to do so and be anchored and linked together correctly to prevent them from falling and creating dangerous situations. Temporary traffic control devices should be flexible or energy-absorbing to moderate the injury outcome of a potential bicycle crash. Fences should have a fine meshed net construction to prevent bicycle handlebars from getting stuck. All road equipment should be designed without sharp edges as they could cause injuries to cyclists passing or crashing into the equipment.

Probing Acetonitrile Solvation in Perfluorsulfonate Ion Exchange Membrane By in-Situ FTIR

In-situ FTIR is a successful tool to study water absorption and interactions within the Perfluorsulfonate Ion Exchange Membrane (PFSA)(1–4). The versatility of the technique can reveal in-depth information related to proton transport in PFSA, including proton dissociation and solvation. Another desirable feature is that experiments under controlled water content(λ) is also possible. Studies of PFSA membranes equilibrated with different λ was fundamental to understand membrane behavior(5). The volatile nature of acetonitrile and many organic solvents adds to the inaccuracy of many classic membrane characterization methods. To overcome this, techniques tailored for membrane incorporated with organic solvents are necessary. In this study, acetonitrile and lithiated PFSA were chosen to revisit the in-situ IR technique. The goal of this work is to examine acetonitrile’s role in membrane swelling and to create a ‘slow-motion picture’ of how acetonitrile molecules behave upon being imbibed into the membrane, especially at low λ. The vibrational signal of cyanide group (~2250 cm-1)does not overlap with other signals from the membrane and is known to respond to dipole interactions by shifting to higher wavenumber(6). This feature makes an acetonitrile-swollen system an even more favorable candidate for in-situ IR study compared to its aqueous counterpart. For studying proton transport in membrane, initial water buildup in membrane yields a weak and broad signal, making the already obscure -OH stretching region even more complicated to analyze. Without interference from hydrogen bonding, lithium ion solvation with cyanide can be clearly observed. Coupled with monitoring -SO3- area, it is totally feasible to simultaneously see both cation dissociation from membrane (Fig.1A) and cation solvation in solvent (Fig.1B) in a real-time manner to compare with fully swollen state. Acknowledgement We gratefully acknowledge the support of this work by the U.S. Department of Energy, Office of Electricity Delivery and Energy Reliability (Dr. Imre Gyuk). We also thank 3M for providing membranes. References Elabd YA, Baschetti MG, Barbari TA. Time-resolved Fourier transform infrared/attenuated total reflection spectroscopy for the measurement of molecular diffusion in polymers. J Polym Sci Part B Polym Phys. 2003;41(22):2794–807.Hallinan DT, Elabd YA. Diffusion of Water in Nafion Using Time-Resolved Fourier Transform Infrared−Attenuated Total Reflectance Spectroscopy. J Phys Chem B. 2009 ;113(13):4257–66.Hallinan DT, Elabd YA. Diffusion and Sorption of Methanol and Water in Nafion Using Time-Resolved Fourier Transform Infrared−Attenuated Total Reflectance Spectroscopy. J Phys Chem B. 2007 ;111(46):13221–30.Kunimatsu K, Bae B, Miyatake K, Uchida H, Watanabe M. ATR-FTIR Study of Water in Nafion Membrane Combined with Proton Conductivity Measurements during Hydration/Dehydration Cycle. J Phys Chem B. 2011 21;115(15):4315–21.Zawodzinski TA, Derouin C, Radzinski S, Sherman RJ, Smith VT, Springer TE, et al. Water Uptake by and Transport Through Nafion® 117 Membranes. J Electrochem Soc. 1993 ;140(4):1041–7.Barthel J, Buchner R, Wismeth E. FTIR Spectroscopy of Ion Solvation of LiClO4 and LiSCN in Acetonitrile, Benzonitrile, and Propylene Carbonate. J Solut Chem. 2000 ;29(10):937–54. Figure.1A: SO stretching shift due to solvation; Figure.1B: Normalized CN stretching area upon acetonitrile buildup in the membrane. Blue dashline indicates corresponding fully swollen state. Figure 1

The Paradox of a Gesture, Enlarged by the Distension of Time: Merleau-Ponty and Lacan on a Slow-Motion Picture of Henri Matisse Painting

In his lecture series The Four Fundamental Concepts of Psychoanalysis (1964), Lacan refers to a �delightful example� that Merleau-Ponty gives in his Book Signes (1960). Lacan describes it as a �strange slow-motion film in which one sees Matisse painting.� This is a scene from the documentary entitled A Great French Painter, Henri Matisse, by director Fran�ois Campaux, a 16mm black and white film shot in 1946. Merleau-Ponty points, as Lacan puts it, to �the paradox of that gesture which, enlarged by the distension of time, enables us to imagine the most perfect deliberation on each of these strokes.� In fact, Merleau-Ponty underscores that this is an illusion, due only to the technique of the slow motion picture. In this paper I will present the different ways in which Lacan and Merleau-Ponty refer to the slow motion picture of Matisse painting. I will do so in order to consider, comparatively, the ways in which Merleau-Ponty and Lacan define the gesture in reference to film technologies and to the process of subjectification. Both of them refer to the gesture in order to find a new balance in the relationship between subject, rationality and media technology. And it is exactly at this site where the question of an ethics of gesture appears.

Slow Motion Picture of Protein Inactivation During Single-Droplet Drying: A Study of Inactivation Kinetics of l-Glutamate Dehydrogenase Dried in an Acoustic Levitator

A novel technique is presented to allow measurement of the kinetics of protein inactivation during drying of an acoustically levitated single droplet. Droplets/particles are removed from the acoustic field after various times during drying, and the state of the protein within them is analyzed. The influence of drying air temperature, relative humidity, buffer concentration, and the presence of a substrate on the inactivation of glutamate dehydrogenase is described. The kinetics of inactivation showed three distinct phases. The first phase of constant drying rate demonstrated little protein inactivation in the solution droplet. After the critical point of drying, a second phase was distinguishable when the surface temperature has risen sharply, but there is still only little inactivation of the protein in the solid particle. An onset point of rapid inactivation of the protein marked the start of the third phase that proceeded with approximately first-order rate kinetics. In the case of L-glutamate dehydrogenase, the evidence suggests that the residual moisture content of the solid and not the temperature alone determines the point of onset of protein inactivation.

Adaptive Fast Full Search Algorithm using Partitioned Region and Optimized Search Order

In this paper, an adaptive fast full search algorithm is proposed. The fast full search algorithm only reduces the complexity of the block matching algorithm used for motion estimation of video coding. Since the spiral search method used in conventional algorithms starts searching at the center of the search range and then moves the candidate position to estimate motion pixel by pixel, it is best for slow motion pictures. The spiral search method usually has better performance than a full search using the raster scan search method. However, the proposed algorithm is best for sequences which have numerous rapid motions. In the first of two proposed stages, using a predicted motion vector, we determine the region search order based on gradient distances among all regions after partitioning the search range. In the second stage, by means of region order, the matching error of all candidate positions is calculated in an optimized search order which is derived from the local image complexity of the current macro-block to search. The proposed algorithm, based on a multilevel successive elimination algorithm, reduces the complexity of motion estimation up to 96.6% on average, compared with the conventional full search algorithm without any loss of image.

세분화된 탐색 범위에서의 방향 지향적 전영역 고속 탐색 알고리즘

본 논문에서는 비디오 부호화의 움직임 예측에 사용되는 블록 정합 알고리즘의 계산량을 줄이는 고속 전영역 탐색 알고리즘을 제안한다. 블록 정합 알고리즘에서 사용되는 기존의 나선형 탐색 알고리즘은 탐색 영역의 중심에서 시작하여 탐색 지점을 화소 단위로 이동화면서 움직임 예측을 수행하기 때문에 움직임이 적은 영상에 적합하다. 본 논문에서는 움직임이 작은 영상 뿐 아니라 움직임이 많은 영상에서도 효율적인 움직임 예측을 하기 위해 다음과 같은 알고리즘을 제안한다. 먼저 초기 문턱 값을 계산함에 있어서 확장된 예측기를 사용하여 보다 최소값에 근사한 문턱값을 계산한다. 그리고 탐색영역을 블록으로 세분화 한 후 각 영역을 새로운 탐색 순서에 따라 움직임 예측을 수행하고 방향성에 따라 영역을 재분할한다. 재분할된 영역이 가지는 방향성에 따라 방향 지향적인 탐색 순서를 적용한다. 실험 결과에서 제안하는 알고리즘이 기존의 나선형 전영역 탐색 알고리즘에 비해 객관적인 화질의 열화 없이 계산량이 평균적으로 약 94% 감소하는 것을 확인할 수 있다. We propose the fast full search algorithm that reduces the computational load of the block matching algorithm which is used for a motion estimation in the video coding. Since the conventional spiral search method starts searching at the center of the search window and then moves search point to estimate the motion vector pixel by pixel, it is good for the slow motion picture. However we proposed the efficient motion estimation method which is good for the fast and slow motion picture. Firstly, when finding the initial threshold value, we use the expanded predictor that can approximately calculate minimum threshold value. The proposed algorithm estimates the motion in the new search order after partitioning the search window and adapt the directional search order in the re-divided search window. At the result, we can check that the proposed algorithm reduces the computational load 94% in average compared to the conventional spiral full search algorithm without any loss of image quality.

Computer-animated illustrations of vibrations and waves

Undergraduate students in a general-education course on musical acoustics often have difficulty understanding the actual time-domain motions of vibrating systems which textbooks can only depict using static diagrams. In particular, students have difficulty relating the longitudinal average displacements of gas molecules in acoustic waves to (transverse) graphs of these displacements as a function of position. To better convey these ideas, a number of animated graphic diagrams have been programmed on a Macintosh computer. For longitudinal waves, these include one-dimensional standing waves in cylindrical pipes with open or closed ends, various pulse waves reflecting from the open or closed end of a cylindrical pipe, and standing waves in a conical pipe with an open end. In addition, the transverse motions of bowed, plucked, and hammered strings have been programmed. Presented in every case is an exaggerated, slow motion picture of the system’s displacement as it evolves in time. If desired, an adjacent coordinated and animated graph of displacement, pressure, or other dynamical variable may also be displayed. As part of this paper the computer programs will be demonstrated.

The wing beat ofDrosophila Melanogaster. I. Kinematics

The wing beat of small insects attracts special interest because conventional aerodynamics predict a reduction of flight efficiency when aerofoils are small and slow. The kinematics of the wing beat of tethered flyingDrosophila melanogasterwere investigated by using artificial slow motion pictures which were generated by single strobe flashes triggered in synchrony with the wing beat. The properties ofDrosophilawing motion are described qualitatively and compared with the published data for other dipteran insects.Drosophilamoves its wings in a pattern that differs considerably from the well-documented wing beat of the bigger blowflyPhormia. By means of a computerized three-dimensional reconstruction, the variables of the wing-beat cycle, such as wing path and angles of attack, are analysed quantitatively. These data will be the basis of aerodynamic calculations presented in accompanying papers.

Semiconductor Laser Pickup for Optical Video Disk Player

Almost five years have passed since the concept of the optical video disk system was first presented, and several kinds of systems have been developed these few years. 1,2,3,4 Recently, the standardization of these confused optical video disks was made and optical video disk player systems have already reached the stage of commercial development.5 Optical video disk systems offer several advantages to mechanical and capacitive video disk systems. High image quality, still and slow motion picture capability are some of its chief attractions. Unfortunately, large, complicated, and expensive optical pickups still remain a problem. Part of the difficulties is the use of the He-Ne laser as a light source. Although the He-Ne laser is one of the most stable and compact gas laser among several commercial available lasers, its size, over 200mm length and 30mm in diameter, is still too large for a compact optical pickup. Moreover, high voltage power supply of over 1.5KV are not desirable for home use systems. In addition, the optical system used in the pickup is quite complex because separate laser beams are used to detect the auto-focusing signal, the tracking signal, and the video signal. These factors make for a very expensive overall cost in labor for manufacturing and maintenance.

High frequency cinematographic investigations of the mode of operation of common drilling instruments on bone and cartilage (author's transl)

High frequency cinematographic films were made of the mode of operation of common oto-surgical drilling instruments on bone and cartilage. Rose bits and surgical fraises of different sizes were used at 5,000-80,000 R.P.M. The evaluation of the slow motion pictures was performed on the running films and by review of single frames. In detail: The preparation of the drilling head on the bone without simultaneous flushing leads to a filling of the cutting channel and decreased cutting. Drop flushing only prevents the increasing soiling of the drilling head if the drop sequence is rapid and which must be markedly increased with increasing R.P.M. of the drilling instrument. Flushing with a stream of water, which definitely prevents soiling, is preferable. Both drop flushing as well as the water stream must continuously wet the drilling head, i.e. must be absolutely centric in every case. Safest is the automatic spray flusing which is mounted on the handpiece, but which has so far not been used in oto-surgery. During the preparation, the air space of the working area is always filled with drilling dust or haze. Cutting is always performed tangenitally. The cutting speed lies between 2,9 m/s to 16 m/s. It depends on the R.P.M. of the drilling instrument. A drill head running out of true, even with a gently percussing shaft, touches the bone only with a part of its cutting surface which strikes more vigorously than desired and easily gets soiled, despite flushing. Cutting is therefore less and uncontrolled. An increased feeding energy (pressure on the support) in order to speed up cutting leads to heavy wear of the drilling instrument and unsafety in handling due to jumping of the drilling head. During each contact of a cutter with the bone, coarse fraises with low R.P.M. (5,000 R.P.M. = 83 R/s) show a short stopping of the rotation which results in a jerk and vibration of the whole preparation and can thus lead to a damage of the inner ear.

Computer‐controlled x‐ray study of Japanese consonants and vowels—a preliminary report

A set of data of Japanese CV syllables has been obtained for two native speakers of the Tokyo dialect by use of the computer‐controlled x‐ray microbeam system [J. Acoust. Soc. Am. 57, 1516–1520 (1975)]. The material included /pV tV kV sV bV dV gV zV/, where V is /i, e, a, o or u/, repeated in immediate succession. For one subject, five pellets were placed on the tongue surface in the midsagittal plane, with another pellet on a lower tooth. The six pellets were tracked at a rate of 120 sample sets per second. The data are being analyzed, and tentative conclusions include: (1) the blade of the tongue (in reference to flesh points) is more advanced for [e] than for [i], (2) k‐g and t‐d oppositions reveal different tongue gestures, (3) for dental consonants, the tongue body makes a characteristic forward movement, and these movements are slower for fricatives than for stops. A slow motion picture of the movements of the pellets will be demonstrated.

Paths of Movement of Body Members in Aircraft Cockpits

This paper describes an effort to study the simultaneous motion trajectories of a large number of human body landmarks of a pilot during upper limb motions typical of those necessary to fly an aircraft. The objective is to gather engineering anthropometric data necessary, from a human engineering point of view, in the design of aircraft cockpits and other similar manned work stations. Twenty subjects participated in an experiment conducted to record the movements. A photographic procedure combining slow speed motion picture and interrupted light photography was employed to record the movements. This paper describes the procedure and also presents a set of typical paths of movement obtained through such recording. Also mentioned are some of the preliminary findings regarding the motion characteristics of parts of the human body.

Analysis by slow-motion picture photography and scanning electron microscopy of radular function in Urosalpinx cinerea follyensis (Muricidae, Gastropoda) during shell penetration

Radular function in the muricid gastropod Urosalpinx cinerea follyensis Baker during shell penetration was examined with slow-motion picture photography and scanning electron microscopy. Particular attention was paid to possible injury of buccal structures by radular cusps. The presence of a flexible cuticulated buccal armature, and delicate synchronization of movements of odontophoral cartilages, subradular membrane, teeth, and buccal mass, explain the absence of shredding of live buccal tissues. Some light abrasion was evident, but generally only in the cuticulated gully of the subodontophoral shield, on the rim of the jaw, and on the anterior edge of the esophageal valve. Rasping at the surface of incomplete bore-holes is done by major cusps of rachidian teeth over the bending plane. Marginal teeth lie on the slopes of the odontophore, generally remain depressed below the level of rachidian teeth, and thus scrape the shell only lightly, if at all. The sharp posteriorly recurved shape of central and lateral rachidian cusps enhances their scooping effectiveness. These teeth produce smooth, conspicuous traces in the soft shell of Mya arenaria and shallow traces in the harder shell of Mytilus edulis Linne. The impact of individual cusp strikes was not evident in traces. With wear, rachidian cusps become increasingly blunted, a reflection of their ploughing action over chemically weakened shell, and are eventually sanded flat. Marginal teeth wear primarily at their ends, the tips becoming truncated as they pass lightly over the shell surface. The advancing edge of the odontophore during rasping strokes, plotted on the image from motion pictures moves slowly at first, then more rapidly in the middle of the stroke, and slows again at the end. Duration of strokes ranged from 0.45 to 0.75 sec. Duration of rasping cycles varied from 1.3 to 2.0 sec. The number of transverse rows of teeth passing over the bending plane during the rasping stroke varied from 14 to 32, and the average time for the passage of one transverse row over the bending plane ranged from 20 to 48 msec. The number of transverse rows of teeth remaining exposed beneath the odontophore below the bending plane at the end of the rasping stroke, and between the bending plane and the anterior end of the sulcus in the radular diverticulum, was approximately 10.

Development of Turbulence during the Build-Up of a Boundary Layer at a Concave Wall

In an apparatus used earlier for experiments in the flow between concentric rotating cylinders, the boundary layer generated on the inner surface of the outer cylinder is investigated. The development of the laminar boundary layer can be calculated. Its instability against cellular disturbances (Görtler vortices) and the transition to turbulent motion are observed by flow visualization. The rapidly passing phenomena are recorded in slow-motion pictures. In regard to the wavelength of the vortices, it is discussed that the occurring vortices are those with maximum amplification. The distinct kinds of transition for different speeds of the initial flow are described.

A Study on the Movement Pattern of Four Limbs in Walking [1

1. The author using 8mm cinecamera (48 or 64 frames per second) observed the movement sequence of four limbs of many mammals while they were walk-ing on all fours. In the slow motion picture, protraction or retraction of each limb was confirmed and the movement sequence of all four limbs was combined. The walking type of many mammals commonly seen in the zoo was "backward cross type" as shown in Fig. 1, but many monkeys showed completely different walking type, "forward cross type", as shown in Fig. 2. These figures show that each limb moves one after another according to the arrows (cf. IWAMOTO & TOMITA 1966).Some examples of walking monkeys are given in Fig. 3-Fig. 6. Names of monkeys which were observed walking with "forward cross type" are shown in Table 1.The prevalence of "forward cross type" in the primates and the "backward cross type" in other mammals is thought to be worthy of notice.2. Movements of four limbs in walking were expressed as the combination of reciprocal movements of right and left fore limbs and that of right and left hind limbs, as shown in Fig. 11-Fig. 12 or Fig. 13-Fig. 15. (cf. Fig. 7, 8, 9). The body support fashion by the limbs while walking with either of the two types was illustrated in Fig. 16 and Fig. 17, 18 (cf. Fig. 10), and the stability of animal body was discussed. In these figures it is obvious that "forward cross type" is rather unstable compared with "backward cross type ". Monkeys may compen-sate the instability in walking with highly developed postural regulation mechanism.3. In walk, ipsilateral fore limb and the contralateral hind limb have the tend-ency of moving together ; and when these two limbs are in retraction phase, either of the protracting two limbs (other fore limb and the contralateral hind limb) must be placed on the ground earlier not to lose the equilibrium of the body if the center of gravity is situated before or behind the line connected between two supporting feet of the limbs. If the center of gravity is before the line, the protracted fore limb must be placed on the ground first ; thereafter "backward cross type" begins. If the center of gravity is behind that line, the protracted hind limb must be placed on the ground first not to tilt the body backwards, then thereafter "forward cross type" occurs.In many non-primate mammals, the body weight falls more heavily on the fore limbs than on the hind limbs (cf. Fig. 19, also IWAMOTO & TOMITA 1966), but in monkeys the body weight falls more heavily on the hind limbs than on the fore limbs (cf. Fig. 20, also IWAMOTO & TOMITA 1966). The difference of the body weight distribution to fore and hind limbs between monkeys and other mammals may be related to the two walking types.4. The author also made dogs to walk with heavy load on the hip. In most cases the animal walked with "backward cross type ", but a few cases of "for-ward cross type" occurred. The author made some discussion on this result. An example of such "forward cross type" walk is shown in Fig. 22.

Cerebral Birth Injuries

1. Cerebral birth injuries are described and the handicaps, both physical and mental, classified from an orthopaedic rather than a neurological point of view in order to facilitate therapy. 2. A neurological diagnosis is nevertheless essential in the survey of the patient in order to rule out other conditions which may be progressive. 3. A careful mental capacity evaluation must be made, taking into consideration the physical handicap as an added factor in determining the advisability of treatment. 4. Treatment is briefly outlined for the various types of dyskinaesia. 5. The use of slow-motion pictures is recommended as a great aid in distinguishing the various types of dyskinaesia encountered and as an aid in recording improvement. 6. Slow-motion pictures were shown illustrating the types described and comparative films as used for record.

Mechanism of melanophore dispersion

The mechanism of the melanophore reaction of the skin of Hyla arborea (tree frog) has been studied. Apart from the specific hormones MSH and ACTH which elicit melanophore dispersion, the following substances produced darkening: theophylline and caffeine regularly, theobromine erratically, but not, however, dyphylline. Sodium iodoacetate and mercuric chloride elicited melanophore dispersion, which fact may be connected with their ability to block active SH groups. Melanophore dispersion is not dependent upon temperature (13–20°); at the unusual temperature of 37° frog melanophore dispersion is, however, inhibited. On the other hand, melanophore contraction is speeded up with increases in the ambient temperature; this points to the working theory that darkening is a passive reaction whereas lightening is an active reaction requiring energy. The assay of different inhibitors for their interaction with the energy supply has shown that only sodium benzoate inhibits melanophore contraction. This points to the possibility that the energy source should be sought either in the lipid metabolism or in the flavoproteins. Melanophore contraction (lightening reaction) was elicited by dyphylline and noradrenaline. The effect of adrenaline, melatonin and serotonin was insignificant. This points to a highly specific reaction of the Hyla melanophores. Based upon our experience of the effect of calcium on the melanophore reaction the theory is advanced that the passive stage of melanophore dispersion (darkening) is induced by entrance of Ca 2+ into the cell and exit of K +. The active stage of melanophore contraction (lightening), however, needs an energy pump for either removal of Ca 2+ from the cell or for forcing in of K +. The melanophore reaction is a convenient ‘slow-motion picture model’ for many coupling phenomena occurring in muscles, glands, nerves, etc.

Stationary Flame Front in a Swirl Combustion Chamber

The combustion process, known as Texaco Combustion Process, eliminates the knock of a conventional gasoline engine by means of the swirling air and fuel injection. Furthermore, it enables the engine power to be controlled by variation of fuel quantity without air throttling. However, the existence of the stationary flame front, which contributes for the elimination of knock, is not yet confirmed. In this paper, the slow motion pictures of flame front in a combustion chamber with air-swirl were taken through the glass window. The result of the experiment reveals that a stationary flame front exists under a certain running condition.

Stationary Flame Front in a Swirl Combustion Chamber

The combustion process, known as Texaco Combustion Process, elliminates the knock of a conventional gasoline engine, by means of the swirling air and fuel injection. Still more, it enables the engine power to be controlled only by variation of fuel quantity without throttling the inlet air. However, the existence of the stationary flame front, which contributes to ellimination of the knock, is not yet ascertained. In this paper, the slow motion pictures of flame front in a combustion chamber with air swirl were taken through the glass window. The result of the experiment reveals that a stationary flame front exists under a certain running condition.

CHONDRODYSTROPHIA CALCIFICANS CONGENITA

In summary, the authors feel that this case, presented roentgenographically, demonstrates, See Images in the PDF file as in a slow-motion picture, the uninterrupted course of events in chondrodystrophia calcificans congenita. The sequence of events leading to fusion of the areas of stippling of the epiphyses is demonstrated. It appears that there is a definite variation in the degree of involvement in the different cases reported, and that those cases with marked involvement and with associated anomalies have a poorer prognosis. The authors feel that the manifestations constitute a definite chondrodysplasia with variation in potentiality in regard to the eventual effect on completion of development.