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This paper reviews gas turbine cycles most favoured for vehicular use. It suggests the single-shaft turbine engine as a possible contender for a lower cost approach, where fuel economy requirements are not met by complexity of cycle but by operation at higher turbine inlet temperatures. The question, ‘Where does the engine end and the transmission begin?’ is discussed, and an example of an infinitely variable transmission is explored as a means for overcoming the performance deficiencies of the single-shaft machine. The paper examines the advantages and disadvantages of this type of turbine engine with respect to acceleration and torque characteristics, fuel consumption, engine braking, initial cost, and design for simplicity and high temperature.

This paper describes what is believed to be the first attempt to make a wet-steam ‘wind’ tunnel. Saturated water is sprayed from a small high-speed rotating disc so that the globules are entrained by a stream of saturated steam at the same temperature in which the disc is immersed. The tunnel is designed for a maximum steam speed of 30 ft/sec in a circular working section of 16-in diameter with steam pressures ranging from a full vacuum to 10 lb/in2 gauge. The entrained globules range in size from 5 to 100 micron, and the minimum nominal dryness fraction is 94 per cent. A sampling technique was developed based on the impressions made by the globules on a prepared slide, and an attempt is made to relate the globule size to the disc size and speed, the injection water flow and the physical characteristics of the saturated liquid and vapour. Globule trajectories were calculated by computer allowing for variation of drag coefficient and acceleration of the entraining steam. In the paper the design of the equipment and the problems encountered both in generating the wet steam and in determining the size of the globules are discussed.

The authors consider that the operation of diesel engines for rail traction is arduous because of the ‘on-off’ operation of the engine duty cycle in service, and hence thermal cycling is more severe than that in other applications. The joint paper discusses the limitations of the cooling systems, the turbo-blower and its lubrication, and the arrangements made to ensure that fuel input is related to turbo-blower speed during acceleration of the engine. The silencing of diesel engines is of additional importance from the exhaust noise aspect and from the mechanical noise of the engine itself. The rating of diesel engines is discussed briefly, as are overhaul life, ease of maintenance, and reliability.

The paper deals with the problems of turbocharging the two-stroke cycle engine. Obtaining a sufficiently rapid drop in the pressure of the cylinder contents after exhaust port opening is chiefly dependent on obtaining a high turbocharger efficiency. However, exhaust-pipe design can be very important in this process, and a system is described which permitted the use of simple turbocharging from light load to 200 lb/in2 b.m.e.p. Good starting and acceleration demanded that energy be fed into the charging system and so the normal engine-driven Roots blower was then fitted as a second stage. This spoiled the good natural match of the turbocharger and engine but it was discovered that by control of air recirculation through the Roots blower a good match could be obtained. The work showed that the best match leads towards a constant horsepower type of engine torque curve, and this fact should be recognized for future vehicle design. The use of two turbochargers in series offers very high outputs with good efficiency but will require a new generation of engines to withstand the high pressures and thermal loading.

The rapid growth of metropolitan areas has created the need for high-speed commuter services around the world. The locomotive-hauled train cannot provide the rapid acceleration and fast braking required to move increasing numbers of people over commutation distances. It is being replaced by the self-propelled or ‘multiple unit’ car. This paper describes research carried out by the Metropolitan Transportation Authority, New York, to develop high-speed equipment for commuter services, and deals firstly with electric cars and secondly with a dual powered car taking power from a third rail and also powered by gas turbines. The tests carried out are described and conclusions reached are stated.

A good central region yields a compact, dense, well-centered beam in a phase interval which will optimize the following acceleration and extraction processes. This paper reviews the role of various central region features in attaining desired beam properties. Results of careful calculations are shown to closely agree with observed beam properties.

This paper gives a general survey of the behaviour of surface vessels subjected to accelerations in a horizontal plane. There are two different cases which frequently occur in combination but which, for convenience, are treated separately. First, longitudinal acceleration is considered, including positive or negative acceleration in the fore and aft plane; problems of stability and manoeuvrability and means of improving directional control are discussed. Next, the manoeuvring problem associated with transverse accelerations is described, with particular emphasis on the use of auxiliary devices, such as side thrusters, and modified propulsive arrangements. Finally, the influences of currents, winds and restricted depth on manoeuvrability are outlined.

This paper describes how London Transport endeavours to evaluate the optimum train performance characteristics necessary to meet the peak service requirements for a given line at minimum total cost to itself and hence to the passenger. The basic factors affecting train performance on a subway system are outlined, and the practical limits to the attainment of ideal performance are described in detail, with particular reference to maximum acceleration, and the high additional energy costs of increasing maximum speed to save time on short runs. A detailed examination is then made for the Victoria Line service, using a digital computer to assess the net effects on capital and running costs of progressively increasing the proportion of motored axles on the Victoria Line trains, and determining whether the consequent improvements in performance are sufficient to operate the same service with fewer trains. It is concluded that for present London Transport conditions the proportion of driving axles cannot be increased beyond the present figure of 50 per cent without increasing total costs, and this is of considerable interest to London Transport in relation to the more heavily motored formations favoured by many Continental and American subways. It is shown that appreciable energy savings can be realized on the Victoria Line by the use of the coasting control feature of the Automatic Train Operation scheme and by the incorporation of the ‘hump station’ principle first used on the Central London Tube in 1900. A comparison is made of the merits of using the hump station principle on a hypothetical new tube line and/or increasing the proportion of driving axles, and it is concluded that the use of even a limited degree of gravity assistance will enable both rolling stock and energy to be saved for a given service, with no increase in the proportion of motored axles.

Using the Frankel-Young method, fast estimation of the potential distribution for a microstrip structure is obtained when an accelerating factor /spl omega/ is introduced in the finite-differences (relaxation) method. It is possible to calculate such a factor by an iterative technique, but the time of computation needed to find /spl omega/ annihilates the theoretical gain. In this short paper, the authors present a method which gives an analytical expression for /spl omega/. The realistic case examined here, as an illustration, is that of the suspended microstrip couplers for which odd and even impedances are the interesting parameters. Given an analytical expression for /spl omega/, the overrelaxation method appears as a very powerful and attractive method for finding the solution of any type of microstrip structure.

Torsional oscillations generally occur in the drive to a fuel injection pump and, depending on the drive arrangement and the conditions of operation, the maximum dynamic torque in the drive can be considerably in excess of the pumping torque. It is necessary to allow for this effect in the design of the engine, drive, and pump components. In this paper the methods of measuring the dynamic torque in the drive shaft and the instantaneous acceleration of the rotor of a distributor pump are described. Results of tests on two typical drive arrrangements, both on an engine and on a test machine, are then shown. A theoretical study is made of the drive system with backlash, and the results are compared with experimental values. It is shown that backlash in the drive can lead to high instantaneous torques and large torque reversals. A design of drive which eliminates backlash is described, and tests carried out on it confirm that the expected improvement is obtained.

The purpose of this investigation was to evaluate the effects of presenting a well structured time-telling program to children at the K-3 level. Twenty classes in two schools (two experimental and three control groups for each grade) participated in the study. Experimental group teachers were selected on three effectiveness criteria, and pretest, posttest, and retention test measures were therefore analyzed using descriptive statistics. The instruction, which lasted ten days and had as its terminal objective telling time to the nearest minute, was found to produce "educationally significant" differences only at the grade one level. No anxiety increases were detected as a result of using the program. In an appended paper, "Curriculum Decision: Learning Time Concepts and Skills," the author relates this instructional achievement to Piaget's car velocity experiments. Curriculum implications are discussed. (The paper is based on the author's doctoral dissertation.) (MM)

The purpose of the conference was to define the role of the School Mathematics Study Group (SMSG) in the preparation of programs and materials for gifted students. The background papers presented at the beginning of the conference and the recommendations made at the conference are presented in this report. Topics covered in the papers include a history of studies attempting to define gifted people, summaries of studies concerned with acceleration and enrichment for gifted students, activities for gifted students, and the problems of organizing special programs for gifted students. The conference gave the highest priority to recommending that SMSG develop supplementary materials. More specific recommendations included writing units of topics for investigation and open-ended research problems for students, developing expository booklets and possible correspondence courses for the mathematically gifted, encouraging and organizing local and regional symposia, organizing NSF summer and inservice institutes for training teachers to work with gifted students, investigating means of identifying gifted students other than by IQ scores, and extending some of the above activities downward into the elementary school. (JP)

Very little material exists for utilizing the computer in the physics classroom, and even that little is not widely known. It is hoped that this monograph will provide some stimulus both to innovation and to discussion of the role of the computer in physics education. The paper describes how this might be achieved with a detailed account of one week of instruction in the physics of the harmonic oscillator, without calculus, for either physics or non-physics majors. The course is organized into three lectures, Days One to Three, and a Laboratory Session. Day One develops the basic first-order numerical integration scheme for computing velocity and position from a knowledge of acceleration and initial conditions. Day Two discusses the nature and languages of computers, and the construction of algorithms for computation, and Day Three is available in four different versions, one for each of the well-known computer languages-- BASIC, FORTRAN, JOSS, and PL-1. A Student Manual and a Teacher's Guide are included in this paper. (GO)

At the present time there is no complete theory for the calculation of velocity and acceleration derivatives for surface ships. A few methods have been published but they fail to take proper account of hull geometry. A strip method is described, based on added mass concepts, which is compared with experiments conducted with a segmented model of a tanker.

Throughways is the name given to an urban rapid transit system that is based on the use of standard buses operating on ordinary urban roads for part of the route and on reserved tracks, either at ground level or as elevated structure, on sections of routes where traffic congestion would ordinarily restrict the speed and make it difficult to predict schedules. On the reserved tracks the buses are automatically steered by a guidance unit. By this means narrow tracks can be used, and the buses can keep up a higher average speed (which is largely independent of weather) than would be possible with manual steering. The system includes automatic signalling equipment, to ensure safe merging of buses from lay-bys and feeder routes into a main stream operating at high density. This is intended not only to help maintain high schedule speeds and high capacities, even in bad weather or poor visibility, but also to reduce braking and acceleration rates, thus contributing to passenger comfort.

Panels of observers travelled short distances in three vehicles, which were identical except for suspension components. The motion experienced by the observers was varied by alterations to tyre pressures, spring rates, dampers, and types of road surface, and was measured by accelerometers and a gyro feeding a magnetictape recorder or a galvo-recorder. Good correlation was found between subjective assessments and simplified data obtained from detailed frequency analyses of the recorded motions of the vehicles. It is shown that the average vertical acceleration passed by a 0·75-6-c/s filter as measured by an accelerometer placed between a passenger and his seat is a good measurement of how subjects react to the low-frequency ride of a vehicle. Higher frequency floor motions, measured as the average acceleration passed by a 7-50-c/s filter, also showed good correlation with subjective assessments. The average angular displacement in pitch passed by a 0·75-6-c/s filter showed some relationship with subjective assessments of pitching of the vehicles, but roll was seldom commented on by the subjects. The simplified measurements of linear and angular motions in two relatively wide frequency bands yield useful ride quality data; the information can be obtained by the use of relatively simple and inexpensive equipment.

High-speed ground transport (150 m/s) to be effective over limited distances also requires high acceleration. Were the power required to overcome air resistance and achieve adequate acceleration provided by conventional means, bulk and mass would be excessive. The linear induction motor offers considerable advantage at high speeds, it is not limited by centrifugal force and is independent of adhesion. A high overhead rating is possible as heat is left behind in the reaction rail. Output of a double-sided machine may be expected to reach 7 lb/in2 (44 500 N/m2) of effective pole face and the system is equally effective in braking. The principle of operation is described. To be efficient the current which is ‘in phase’ with the applied voltage must be made as large as possible compared with the magnetizing current, operation must be at low values of slip and the surface speed of the travelling field should be high. Thus a quantity known as the ‘goodness’ of a machine may be described by the expression where μ0 is permeability of free space; ρr is surface resistivity of rotor; p, pole pitch; g, total effective air gap in the magnetic circuit; and Vs is surface speed of travelling field = synchronous speed of vehicle. Because of the simplicity of the construction, g is necessarily larger than would be the case for a conventional machine and ρr is less favourable. However, these can be compensated for by increasing p with a suitable adjustment of frequency and the effect of the term Vs is such that the linear motor becomes better the higher the speed at which it is required to operate. Tests on a linear motor at Gorton are described and some of the mechanical problems of applying linear propulsion to railways are discussed.

For the extraction of the beam in an AVF cyclotron a regenerative system or an electrostatic channel can be used. Some factors of importance for the beam will be discussed. Extraction with an electrostatic channel can give very high external beam quality and extraction efficiency. For such a system it is of importance whether the beam is extracted before or after the ?R=1 resonance. The beam can even pass the ?R=2?Z resonance without blowing up vertically if attention is being paid to the radial oscillation amplitude and some machine parameters. The general orbit theory can be used for an analytical study of a regenerative system in an A.V.F. cyclotron.

The goal is a continous external proton beam of the order of 100 ?A, the usable current depending mainly on extraction rate because of activation. The energy of 500 MeV is best suited to produce high fluxes of low energy or stopped mesons. The main fields of the research are planned to be: properties and interactions of mesons and nucleons, nuclear structure physics and medical and biological applications. The use of internal targets in field free regions as well as external targets should provide a great variety of beams for simultaneous experiments. The two-stage accelerator has a 70 MeV sector focussed cyclotron for injection into an isochronous ring accelerator consisting of eight spiral sector magnets. Four cavities operating at 50 MHz should provide at least 1 MeV energy gain per turn. In the course of present development the main fields of work are orbit dynamics and measurement on 1:5 scale magnets and design of a 1:1 model magnet sector. vZ is to be kept around 0.95 throughout acceleration and vr = 1.5 may be used for resonance extraction. Experiments to reach high gap voltage on a full scale cavity in vacuum are in progress (200-300 kV obtained at present). Remaining problems are some aspects of mechanical structure, in particular the vacuum chamber and schemes for quantitative extraction and secondary beam production from external targets at very high radioactivity levels. Funds of 21 Million Dollars have been approved for construction of accelerator and buildings.

The running of passenger trains in regular service at speeds up to 100 mile/h is now of common occurrence on a number of railway systems. Above this speed it is necessary to use specially prepared tracks maintained to the highest possible standards at very considerable cost in terms of money, special equipment and time. It is possible to identify three broad classes of modern high-speed railway: (1) where the occasional high-speed train runs in between lower speed services; (2) where the best has been done with an existing railway to make it suitable for a high-speed train service; and (3) specially constructed lines. In all cases there are certain limitations on the acceleration effects to which the passenger may be subjected. Stopping from the highest speeds requires braking distances such that current ideas and requirements on emergency braking become meaningless. High standards of mental and physical soundness are required of drivers: even so, the driver's reaction to lineside signals is too slow, and external control of train speed by lineside detection systems will be required, linked inductively to regulating equipment on the train. Provided that a suitable line of route is available there appears at present to be no precise engineering limitation to the attainment of the highest speeds on rail which will intervene before a cost ceiling is reached at which further increases cannot be justified. There may also be a limit to the rate at which passengers can contemplate changes of scenery.

A novel guide-magnet configuration has been devised which makes possible the acceleration of all charge-to-mass ratios from 0.04 to 1. A concentric storage ring, with the associated beam-switching equipment, allows for the extension of beam duty factor to essentially 100%. The storage ring can also be used in a bootstrap acceleration of heavy ions in which the ions are injected at low e/m, accelerated to a moderate velocity, stored while the accelerating ring returns to minimum field, stripped to maximum e/m, and re-injected for further acceleration. With a pressurized 2.5 MV Cockcroft-Walton injector, the proposed system is capable of accelerating all ions from protons to uranium--to energies up to 1.5 BeV for protons and 0.3 to 0.5 BeV/nucleon for the heavier ions. Intensities of 1012 to 1013 nucleons/sec for the lighter ions (M ? 128) are anticipated. The heavy-ion charge-exchange probabilities determine the vacuum requirements of this system. To minimize these requirements and to increase beam intensity, a 60/sec cycling rate has been chosen. The vacuum requirements and the special rf resonator and beam-switching problems attendant with the high cycling rate are discussed.

The exact solutions given in [1] are generalized to the case of cylindrical and spherical sectors rotating about the azimuth relative to the coordinate origin either at a uniform rate or with uniform acceleration (or deceleration). The class of equations of motion of the boundaries of the half-space (in the Cartesian coordinates) which lead to exact solutions of the Fourier equation defined in these domains, is enlarged.

This paper reports the speed and lateral placement of vehicles on acceleration and deceleration lanes of various designs as constructed in Indiana. It also correlates acceleration and deceleration lane design with traffic behavior and apparent driver requirements, and suggests acceleration lane and deceleration lane design (or designs) which appears to provide the most efficient and safe operation.

This research study on the use of acceleration-deceleration lanes will provide a factual background regarding traffic behavior as affected by acceleration and deceleration lane geometry. The purposes of this research are: 1) To determine the speed and lateral placement of vehicles on various designs of acceleration and deceleration lanes on highway type facilities. 2) To correlate acceleration and deceleration lane designs with traffic behavior and driver requirements and determine the acceleration and deceleration lane design or designs which provide the most efficient and safest operation. This paper deals only with the progress obtained to date in this research study. It describes the results obtained on two study locations - the Indiana Toll Road and Interstate 65 in the vicinity of the city of Lebanon.

This research paper is concerned with the analysis of the capacities of three different freeway on-ramp designs - on ramps with no acceleration lane and stop-sign control, on-ramps with no acceleration lane and yield-sign control, and on-ramps with an acceleration lane and no sign control. The study includes the development of criteria for defining both possible and practical capacities, the development of a deterministic queuing model for predicting possible capacity, the development of a Monte Carlo simulation model for the study of ramp flow under varying traffic conditions, the evaluation of vehicle delays and queue lengths incurred by on-ramp vehicles for various combinations of ramp and shoulder-lane traffic volumes, and the evaluation of possible and practical on-ramp capacities for the three different ramp designs.

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The paper examines the problem of highly gifted junior high school students who are intellectually ready for college-level study before beginning high school. The term radical accelerates is used to describe gifted students who jump from junior high to college education, bypassing the high school years. Briefly described are two widely known and successful radical accelerates, Norbert Wiener and Charles Fefferman. Presented in greater detail are case histories of two boys who are current radical accelerates. Methods used by the authors in seeking out mathematically and scientifically precocious students of junior high school age are explained. Possible disruptive effects of academic acceleration are considered, with particular reference to social and emotional development. Previous literature on acceleration is referred to, although little study has been done on radical acceleration. Radical acceleration is seen as the method of choice for some, but not all, extremely able students; alternate possibilities are also mentioned. (KW)

This paper examines programs of course credit by examination in American higher education. After a brief sketch of the credit-hour system, various programs in actual operation are described. The ensuing analysis focuses on the following issues: appropriateness of various subject-matters to programs of credit by examination; attitudes towards credit by examination; results for participating students of credit by examination programs; financial costs and benefits of credit by examination; and patterns of examination design and administration. A four-page bibliography is included. (Author/CL)

The present study explored the characteristics of students who take advantage of the option to complete the B.A. degree in 3 years at Goucher College. At Goucher, the optional 3-year degree plan has been selected by students of exceedingly diverse academic potential and background, and different ideas of what for them constitutes a successful educational experience. No evidence was found that the students who chose acceleration were those who might have been, on the basis of academic predictors, selected by the faculty or by admissions personnel to pursue such a program. Students attracted to a 3-year program include, in sizeable numbers, those who are motivated by strong vocational aspirations, often coupled with financial concerns. For other accelerants, however, the desire to graduate early has little relation to either financial considerations or career plans, but may simply be a way of escaping the educational scene. Students who prefer to stay for 4 years may represent 2 groups: those who enjoy the college scene for its social and extracurricular aspects, and those who desire to pursue graduate study but are more concerned with adequate preparation and high grades than with the time element or financial expenditures involved. (HS)

In fall 1969, the University of Minnesota Medical School implemented a new curriculum and the option for students of graduation in either 3 or 4 years as an experiment designed to decrease the shortage of practicing physicians. The purpose of this paper is to describe similarities and differences between 3 and 4 year graduates. The results of the study suggest that there are essentially no differences between 3 and 4 year students in entrance scores, demographic data, academic performance during the first 2 years of medical school, or scores on a nationally standardized basic sciences certification examination. There may be a tendency for the 2 groups to differ on clinical competence or knowledge of clinical sciences; however, other factors exist that could explain these findings. (Author/HS)

A program to facilitate instruction for mathematically and scientifically gifted junior high students was described. Compared were nine educational alternatives for the gifted such as homogeneous grouping and early admission to college in terms of educational goals such as allowing for individual differences. Thirty-five scorers in a science fair competition were evaluated individually and detailed analyses of seven of the students' test scores and backgrounds were given. It was recommended that the students take college courses, or enter college early. It was reported that family background of the students usually involved bright parents though not all parents were college educated or in professional occupations. No obvious differences in college class participation between college students and the junior high students were found, and no grade of less than B was reportedly received by a student taking a college course. Mathematical knowledge appeared to derive from independent study or from working math puzzles. Briefly noted was a Saturday class in algebra, geometry, and trigonometry for a group of 22 mathematically gifted sixth graders. To stimulate the highly talented, schools were encouraged to identify advanced students, provide additional testing and counseling, and allow flexible scheduling and program planning. (DB)

This paper reports the results of the experimental use of new remedial education techniques in three urban out-of-school Neighborhood Youth Corps programs. The use of these techniques and the evaluation of the results of these techniques constituted the Accelerated Learning Experiment. The research design called for study groups of 50 each in three different cities, using the education system and materials developed for the Job Corps Conservation Centers. Measures of academic achievement of enrollees were taken at the beginning of the program and again after three and six months. Bi-weekly reports on each student and program progress were prepared by the instructors. The three cities selected for the Accelerated Learning Experiment were: St. Louis, Missouri; Cincinnati, Ohio; and, Pittsburgh, Pennsylvania. Each of the sites was provided with the criteria for an "ideal" experiment, and arrangements were worked out in each city for the most feasible programs in relation to local problems and conditions. Teachers from all three cities were brought together in Pittsburgh in early February, 1968, and were trained by a Job Corps staff member in the use of the Job Corps materials. During the course of the Experiment, educational consultants visited the classrooms periodically to assist teachers with any problems that they had encountered. (Author/JM)

It is argued that aptitude and achievement tests designed for much older students are invaluable for finding extremely high ability at younger ages, particularly in mathematical and verbal reasoning. Results of the first two years of the Study of Mathematically and Scientifically Precocious Youth (SMSPY) are examined to show that considerable educational acceleration is not only feasible but also desirable for those young people who are eager to move ahead. Skipping school grades, taking college courses part-time, studying in special courses, and entering college early are proposed. These are simple to carry out. inexpensive, and supplemental to regular school practices. The SMSPY staff does not advocate the usual in-grade, non-accelerative "enrichment" procedures often recommended for intellectually gifted children. The approach in this paper is via cases and references to numerous SMSPY studies. It is meant to be an heuristic overview of the main assumptions and findings. (Author)

While most administrators are primarily interested in the economies offered by the extended school year, it is the opportunities for increasing educational quality which should receive primary attention. The knowledge explosion in the past 70 years dictates this focus. There are four basic ways of rescheduling the school year: (1) The staggered quarter plan and its many variations, in which the schools operate year-round with vacations spread throughout the year; (2) the extended school year (204-212 days), with economies arising from student acceleration; (3) the summer school programs for remedial, makeup, or enrichment work; and (4) the Multiple Trails Design. The Multiple Trails Design is the most flexible of the plans since it does not rely on term rotation or acceleration to achieve desired goals and it allows educators to be innovative. It allows for individualized programs, acceleration, and enrichment, and gives teachers time for individual development. Computers programed with many rescheduled school years will soon be ready to provide individual school districts with programs which will best fit their needs and conditions. Vacations are becoming year-round phenomena and should not hinder year-round schools as they did in the past. (HW)

A workshop was held at George Washington University to consider the shortage of adult educators to meet the needs created by the Federally assisted programs in adult education and possible ways to prepare a wide variety of adult educators in large numbers, in a short period of time, without lowering professional standards. Discussion centered on three pre-workshop papers on the training of local leaders as teachers of functional illiterates, the development by universities of short term study programs for these teachers, and the need to reach and encourage those who do not participate in community affairs. Suggestions reflecting majority opinion emerged. Universities and institutes should be more fully used, perhaps with new university offices to coordinate the new Federal programs with departmental and faculty resources, and with institutes planned two years ahead. Estimates of local needs should be made realistically; an information clearinghouse should be set up by the Office of Education or other group. Professors should determine if they can contribute to the program and, if so, should be given financial assistance. Long and short range goals should be clearly differentiated. (jf)

An overview of educational and psychological literature concerning the gifted is presented in 55 papers with editorial comments. The historical development of the study of the gifted and cultural attitudes are first considered. Discussions of the effectiveness of various screening methods for identifying the gifted include evaluation of creative, social, and other nonintellectual factors; suggestions are given for providing an optimal environment. Theories are discussed about hereditary and environmental influences on mental ability with ideas for conserving and increasing our supply of superior mental talent. Writings on the characteristics of eminent scientists, unstable geniuses, superior college students, and younger gifted children are included in a consideration of the gifted individual's intellectual, social, and emotional characteristics. Special programs to help develop and encourage giftedness, such as acceleration, enrichment, and homogeneous grouping are described and evaluated; current issues and needed research are considered; and teacher qualities judged effective in aiding creative growth are discussed. (RM)