Bulletin 225 June, 1928 The Lighting of Nebraska Rural Homes by Kerosene and Gasoline Lamps GRETA GRAY Department of Home Economics THE UNIVERSITY OF NEBRASKA COLLEGE OF AGRICULTURE EXPERIMENT STATION LINCOLN W. W. Burr, Director SUMMARY The lamps owned per household number 3.8. Of these 2.6 are ordinary kerosene, 0.3 are round wick kerosene, 0.08 are kerosene mantle, and 0.8 are gasoline lamps. The average cost for upkeep per year per household, not including fuel, is $2.04. In households using ordinary kerosene lamps only, the average cost is $1.27, and in households with ordinary kerosene lamps and other lamps the average cost is $2.17. Forty-five minutes per week per household are spent in the care of lamps, and 50 minutes per week per household in those households having ordinary kerosene lamps only. Approximately 82 per cent of the kitchens and sitting rooms are lighted by one lamp each, 17 per cent by 2 lamps each, and 0.7 per cent by 3 lamps each. Less than 30 per cent of the lamps are above eye level. Twenty-eight per cent of the lamps are shaded. The light most frequently found in the kitchen is that furnished by one unshaded kerosene lamp placed below eye level. The light most frequently found in the sitting room is that furnished by a shaded gasoline reading lamp placed on a table. In a kitchen 12 feet by 14 feet with light ceiling and walls the illumination from the unshaded ordinary kerosene lamp on the work table when this is at the average distance from the lamp is 0.25 foot-candles. Under similar circumstances the illumination on the stove is 0.18 foot-candles, and the illumination on the sink or water bucket is 0.12 candles. In a sitting room 12 feet by 14 feet with light ceiling and walls the illumination from the shaded gasoline reading lamp at the edge of a table 42 inches in diameter with the lamp at the center is 8.0 foot-candles. Under the same conditions, the illumination at the edge of a table 52 inches in diameter is 5.25 foot-candles. The intensity of illumination in Nebraska homes lighted by kerosene and gasoline lamps is far below the standards set by illuminating engineers. There is a great deal of glare in these houses, the distribution of light is very poor, and there are harsh, objectionable shadows. The lighting might be improved by 4 methods: first, by using moEe of the higher-candle-power lamps; second, by using two or more lamps per room; third, by putting the lamps in the kitchen above eye level; and fourth, by shading all lamps. The first two methods would increase the intensity of illumination. The second, third, and fourth methods would improve the distribution of light and eliminate some objectionable shadows. The third and fourth methods would prevent glare. The Lighting of Nebraska Rural Homes by Kerosene and Gasoline Lamps The purpose of this investigation has been to determine, first, how much of the housewife's time is occupied in the care of kerosene and gasoline lamps, second, the cost of the upkeep of these lamps, and third, what the lighting conditions are in Nebraska rural homes without electricity or gas light. The reported expenditures of time and money for the care and upkeep of the lamps pertain to the care and cost of all the lamps and lanterns used. However, only the lighting of the kitchens and of the rooms used as sitting rooms has been considered and compared with accepted illumination standards. Data were collected from 184 homes by 10 persons resident in the communities represented in this study. All but 6 of the homes are in the eastern part of the state. All the data asked for on the study sheets used were not obtained in every case. Table 1 shows the tenancy, the average value of the tarm and buildings, and tbe a veraS- �JI?>?r of person?, per household. Table 1.�Tenancy, value of farm and buildings, and size of household Number of households in group Value Size Tenancy- Number of households reporting this item Average value Number of households reporting this item Persons pei household All ........................................ 184 j 46 $12,574 180 4.16 Owners ................................ 70 16 14,353 68 3.48 108 29 11,651 107 4.56 Ownership not stated........ 6 1 11,000 5 4.8 Table 2 gives the types and numbers of lamps owned and used daily. Fig. 1 shows the percentage distribution of the types of lamps used. There are more than 3 times as many Nebraska Experiment Station, Bulletin 225 Table 2.�Lamps and types per household owned and used daily Number of households reporting these items Type of lamp All O.K.* 1 1 R.W.K.* | K.M.* gas* 1 1 Owned ................ 177 3.8 2.6 . .3 .08 .8 Used daily.......... 120 2.9 Used daily in households with O.K. only ................1 29 I 2.9 2.9 * O.K.�Ordinary kerosene lamp; R.W.K.�Round wick kerosene lamp; K.M.� Kerosene mantle lamp ; gas�Gasoline lamp. ordinary kerosene lamps as gasoline lamps. The ordinary kerosene lamp is the No. 2 burner flat-wick lamp; the gasoline lamp is in almost every ease one with 2 mantles about one and one-half inches long. M Table 3 presents data as to the cost in .. J^onevJo? the apkcep, deluding the cost of fuel, and in time for the care of lamps. The amounts of money and of time reported are estimates in most cases. The average sum of money spent in households having only the ordinary kerosene lamps is less than that spent in those households which have other lamps as well as ordinary kerosene lamps. Most of the ordinary kerosene lamps found in this study are without shades, as e lo_ < GO �a u. SO o m 4� tf <*L * Z �o_ � ^rr- SiO_ 0 �1* < c _ja_ O nary kerosene lamp, R.W.K. is round-wick kerosene lamp, K.M. is kerosene mantle lamp, and -1x71 f�lcci GAS is gasoline wi^n. lamp. Fig. 1. Percentage distribution of lamps owned by 184 house- nardvS'ke?ofenisiamp; may be seen in Tables 8 and 9 and in Fig. 3, so in the majority of cases the only expense aside from that for fuel is for chimneys and From Tables 8 and 9 and Fig. 3 it may be seen also that the greater part of the lamps other than the ordinary kerosene are gasoline lamps, and over half of these gasoline lamps have shades. Shades are frequently broken when the mantle breaks, and it seems reasonable that the money spent for shades and mantles for these lamps should be more than that spent for the upkeep of the kerosene lamps. The reports summarized in Table 3 as to the relative amounts of time spent in the care of ordinary kerosene lamps only and in the care of all lamps are what might be expected, because the chimney and the wick of the Lighting of Nebraska Rural Homes 5 Table 3.�Expenditure per household in money for wicks, mantles, generators, chimneys, and shades; and in time for the care of lamps Expenditures 1 in money j Expenditures in time Households Number of households reporting this item Expenditures per household per year Number of households reporting this item Number of times per week per household lamps are cared for Min. per week per household All ............................................ 165 $2.04 123 4.5 45 With O.K. lamps only.......... 33 1.27 30 4.5 50 With O.K. lamps and others 126 2.17 1 kerosene lamp need frequent attention, while the gasoline lamp requires little care. Nine persons are known to have kept accurate account of the time spent in caring for lamps. These 9 averaged 43 minutes a week, which agrees very closely with the average of the estimated intervals of time. With kerosene averaging a little over 15 cents a gallon and electricity at 11.7 cents per kilowatt hour, Kunerth (10)* found the cost of kerosene and of electricity the same for equal amounts of illumination from No. 2 burner flat-wick kerosene lamps and from tungsten lamps. For 1,000 mean spherical candle-power hours from either source, the cost at the above rates was 19 cents. A quart of gasoline burns from 10 to 13 hours in the gasoline reading lamp with a mean spherical candle power of over 100; therefore, less than one quart of gasoline is required to furnish 1,000 mean spherical candle-power hours. In order to determine the lighting conditions in the homes studied, data were secured as to the following items: the sizes of the kitchens and sitting rooms, presented in Table 4; the uses of these rooms, presented in Table 5 and Fig. 2; the distances from the lamp to the different work places, shown in Tables 6 and 7; and the number, type, position, and shading of the lamps used, given in Tables 8 and 9. Complete data were secured as to the lamps in 298 rooms. Two hundred and forty-four rooms are lighted by one lamp each. The facts as to the kind, position, and shading of these lamps are shown in Table 8. Fig. 4 shows how the rooms lighted by * All figures in parentheses are references to literature cited on the last page. 6 Nebraska Experiment Station, Bulletin 225 these lamps are distributed according to the type, position, and shading of the lamp. Fifty-two of the rooms are lighted by 2 lamps each. Twenty-two of these rooms are in 11 homes. Two rooms in the same house are lighted by 3 lamps each, all of them ordinary kerosene lamps. The distribution of the rooms with more than one lamp as to number, position, type, and shading of lamps is given in Table 9. Fig. 5 shows how the rooms lighted by one lamp compare in number with the rooms lighted by 2 or more lamps. Fig. 6 gives a comparison of the percentages of lamps above eye level and of shaded lamps in rooms lighted by one lamp and in rooms lighted by more than one lamp. Table 4.�Floor areas of rooms Number of rooms in group Floor area in square feet Mean Median Mode Range Quartiles Rooms Qi Qa All kitchens...................... 179 168 168 168 63-320 121 225 All sitting rooms............ 178 202 195 168 72-620 168 225 Kitchens not sitting 148 159 144 168 63-320 120 192 Sitting rooms not 147 200 192 168 72-620 168 224 Kitchens used as sitting rooms.............................. 31 208 195 168 120-320 168 253 From Tables 8 and 9 the following facts may be noted: In all kitchens and sitting rooms there are as many ordinary kerosene lamps as higher-candle-power lamps. In rooms with one lamp only there are 50 per cent more higher-candle-power lamps than ordinary kerosene lamps; that is, in 3 out of 5 rooms lighted by one lamp the lamp is a round-wick kerosene lamp, a kerosene mantle lamp, or a gasoline lamp. Thirty-two of the 54 rooms with more than one lamp have ordinary kerosene lamps only, and in 13 of the rooms with 2 lamps one of them is an ordinary kerosene lamp. In kitchens not used as sitting rooms there are more than twice as many ordinary kerosene lamps as other lamps, while in sitting rooms not also kitchens there are fewer than half as many. There are nearly twice as many kitchens lighted Table 5.�Artificial light sources and the use of all sitting rooms, with respect to the work done in which close discrimination of detail is necessary, and to the number of occupants No. of rooms in group Use of sitting rooms Percentage of rooms in which indicated operations are conducted Number of persons per household Number and kind of lamps Sewing Accounting Reading Study All four Three Two Average Median Mode Range One O.K...............................| 31 ! 61 42 | 97 45 16 45 84 4.3 4 3&4 1-10 Two O.K...............................| 15 b 87 33 | 100 | 60 7 80 100 5.0 4 1 4 2-10 One gas or better..............| 95 87 53 99 j 54 22 69 99 4.3 4 4 1-12 o ~q 8 Nebraska Experiment Station, Bulletin 225 IV/V 20. � &> 1 %2� <* ~� 2 +� �1 �on "5j| z *> s* O i o 5 >- Of uj tf * y o of * * v * a > Or Ui c 1SL UI 2 Ul or c �- a tat Vl < a < *** a > F < < Ml Or O 1- a c _ � OOOM� WITH O/U O.H LAMP 0OOMS WITH TWO O.K. LAM 05 QOOMS WITH OAje C�A4 LAMP 0* feETTEft Fig. 2. Percentages of rooms in which indicated occupations are conducted and the number of persons per household in sitting rooms lighted by one ordinary kerosene lamp, by two ordinary kerosene lamps, and by one gasoline lamp or better. by one ordinary kerosene lamp as are lighted by one better lamp. There are nearly 4 times as many sitting rooms lighted by one lamp better than the ordinary kerosene lamp, as by the latter. In the kitchens 60 per cent of the ordinary kerosene lamps and 61 per cent of the other lamps are below eye level. In the sitting rooms 90 per cent of the ordinary kerosene lamps and 75 per cent of the other lamps are below eye level. Ninety-six per cent of all ordinary kerosene lamps and 97 per cent of those below eye level are unshaded. Fifty-two per cent of all higher-candle-power lamps and 43 per cent of those below eye level are unshaded. The light in the kitchens is most frequently furnished by one ordinary unshaded kerosene lamp placed below eye level and that in the sitting room by one higher-candle-power lamp shaded and placed on a table. An attempt has been made to ascertain approximately and to compare with recognized lighting standards the following factors of illumination as found in these Nebraska sitting rooms and kitchens: first, the intensity of the illumination at the various work centers; second, the extent to which glare exists; and third, the diffusion and the distribution of the light. These factors of illumination depend upon the number and the candle power of the lamps used, their positions, their shading, and the reflecting surfaces the light meets. The lumens from a kerosene lamp are constantly changing and vary with the quality of the oil, the clogging of the wick, the height of the flame, the fogging of the chimney, and atmospheric conditions. The lumens emitted by the gasoline lamp depend upon the pressure and other operating conditions. Kunerth in " Illuminating Power of Kerosene " (10) states that he found the mean spherical candle power of different oils burned in the No. 2 flat-wick burner at the optimum ad- Lighting of Nebraska Rural Homes 9 *m QQUA iu 70\ 10 10 c U. ur 30 of � S-50 52 >oo| |J0 1*0 tfo| t40 160! m\ ted L2pt *>ofc g�o 2*oj 2ffQl H i I P^j lA�P> i* ALU QOOMS i B" H\*\er fc-n $ LAMPS IN LAMPS IN LAMPS KITCHEN* NOT KITCHENS IN OTHCR USEOAS %|T- U58D A* SITTING TlAKi QOOin atTTIAIQ ROOM ROOMS Fig. 3. Location, number, type, and shading of rooms. The crosshatched areas 354 lamps in 298 kitchens and sitting indicate shaded lamps. justment to be 9.3. The Bureau of Standards of the United States Department of Commerce is authority for the following statements: The horizontal power of the No. 2 flat-wick kerosene lamp ranges from 5 to 9 or 10; 7 is a good average for a well-adjusted lamp, and the mean spherical candle power is only slightly less than this. The candle power of the round-wick kerosene lamp ranges from 20 to 25 candles and under very careful adjustment to 30 candles. Kerosene 10 Nebraska Experiment Station, Bulletin 225 Zl^ rzta tin o 29 35 1 I KITCHENS 1 SlTTlrtQ QMS Fig. 4. Percentages of kitchens not used as sitting rooms and of sitting rooms not kitchens, lighted by one ordinary kerosene lamp, by one round-wick kerosene lamp, by one kerosene mantle lamp, and by one gasoline lamp, above and below eye level, shaded and unshaded. The crosshatched areas indicate the percentages of rooms with shaded lamps. mantle lamps give about 60 candles. The horizontal candle power of the gasoline reading lamp is approximately 175 candles under conditions of maximum efficiency. The Bureau of Standards has no measurements on the mean spherical candle power of this lamp, but estimates it at from 125 to 140 candles. This reading lamp has 2 mantles placed side by side so that the distribution is quite uneven as may be seen in Fig. 7, which is reproduced from Fig. 4 in " L i g h t i n g for Country Homes and Village communities " (11). The candle power of this lamp in the horizontal direction, in which it is least, is about half of that in which it is greatest. The brightness of the flame of the kerosene lamp depends upon several things, as does its illuminating power. Kunerth (10) gives 6 candle power per square inch as the brightness when the flame of a No. 2 flat-wick burner is at its optimum adjustment. When the flame was lower than this he found it brighter and when the flame was higher he found the brightness less. He found that the brightness varied with the oil used, depending upon the density of the oil. Ferry (6) gives 5 lamberts, or a little over 10 candle power per square inch, as the brightness of the ordinary kerosene flame. The brightness of the kerosene and gasoline mantle burners greatly exceeds that of the kerosene flame. As is shown in Table 4, a room of 168 square feet is the one most frequently found in this study, a 11 h o the room of average size is somewhat larger and sitting rooms tend to be larger than kitch- KITCHEAS NOT U5ED AS 5ITTINQ QOOM 2 LAMPS I LAMP KITCHENS I |aLAMP5 USED AS ------�-. MTTIMCi ROOM I_____I l LA*+*>�> OTHfP SlTTINQ ftOOtt* 2 LAMPS \ LAMP o to 20 30 40 so go 70 ao 9d no uo NOAAftlQ Or 0OOM5 Fig. 5. Number of rooms with one lamp and with two or more lamps. Lighting of Nebraska Rural Homes 11 * * * Z < < < * o X X 6 6 dz ^ ^ a a ^ O/MWOC nc i rAe >LC o/* ST< >V1 E OAi 6IA1K CODE Fig. 8. Contrast between the foot-candles required and recommended by lighting code and those received in kitchens lighted by kerosene and gasoline lamps. The first section of the chart shows the foot-candles required and recommended by " Code of Lighting Factories, Mills, and Other Work Places " for the type of work done in the kitchen. The other sections show the foot-candles received at the worktable, stove, and sink when these are distant from the lamp 3.3 feet, 5.7 feet, and 7.3 feet respectively and the lamp is on a table. The distances from the lamp are the mean distances found in this study. Minima and maxima of illumination are given because the distribution on a horizontal plane of light from the ordinary kerosene and from the gasoline lamp is not the same in all directions from the lamp. The foot-candles charted in the second, third, and fourth sections were those measured in the test room described in the text. 18 Nebraska Experiment Station, Bulletin 225 ? Q 5-a. 8-^ glare, may be secured in these rural Nebraska kitchens by placing an ordinary kerosene lamp, which is the one most frequently used, above the head and using a suitable shade. A table lamp may be set upon a high shelf but there are bracket and hanging kerosene lamps which may be used. One of the higher-candle-power lamps above the eye level and so shaded that the flame or mantle is out of the range of vision would improve the kitchen lighting still further. There are gaso line bracket and.hanging lamps so designed that the fount is against the wall or ceiling and, therefore, its shadow is out of the way. T h e s e are some what better than the gasoline table lamp for use above the head. In general, no one lamp, even if of suf-f i c i e n t candle power, can light satisfactorily a 11 the work places in the kitchen. At one, or at more of them, no matter where the light is placed, the work surface will be shadowed by the worker standing before it; therefore, a second lamp is needed. Properly shaded lamps below the eye level may be used with satisfactory results, but in most kitchens more than 2 lamps below eye level would be necessary to meet good lighting standards. A shade on a lamp increases the amount of light below the horizontal plane passing thru the light source and when the lamp is above the eye level in a room of ordinary size it provides a better distribution of light, concentrating it in i�n rr U \* N�< O O CM CM �7 Z Z Z * ! < I Z CODE OfiAZ Irt.TA&LE. OH SZ 1/M. TABLE Fig. 9. Contrast between the foot-candles required and recommended by lighting code and those received in houses lighted by kerosene and gasoline lamps. The first section of the chart shows the foot-candles required and recommended by " Code of Lighting Factories, Mills, and Other Work Places," for work in which discrimination of minute detail is necessary, as in sewing and reading. The second and third sections of the chart show the foot-candles received at the edge of a table 42 inches in diameter and cf one 52 inches in diameter from different lamps placed at the center of each table. Minima and maxima of illumination are given because the distribution on a horizontal plane, of light from the ordinary kerosene and from the gasoline lamp is not the same in all directions from the lamp. The foot-candles charted in the second and third sections were those measured in the test room described in the text. Lighting of Nebraska Rural Homes 19 that part of the room which is occupied. In many cases an unbreakable metal shade may be used upon a lamp placed above the head, for when in this position it is not often necessary that any light pass thru the shade. The inner surface of any shade used on a lamp in this position should have a high reflection factor in order to direct as much light as possible into the lower part of the room. The light source in a shaded lamp above eye level, or even below it, may still be within the range of vision and therefore glaring. One large company manufacturing gasoline lamps has done some experimenting with diffusing bowls in an effort to hide completely the light source of the lamp when it is above the head. At the present time, however, they have not been able to make this practical. A shade on a lamp below the eye level, while increasing the illumination in the space immediately around and below it, lessens it at other points in the lower occupied part of the room. Almost all the shaded gasoline lamps found in this study have an opal shade, the brightness of which is within the permissible limit. Altho this shade concentrates the greater part of the light into the space below it, enough passes thru to give a ground work of light in which to see one's way about. Such a shade as this is desirable when there is only one lamp and it is placed on a table. To improve the illumination of the sitting rooms, the lamp in every case should be shaded and if one properly shaded lamp does not give a background of illumination high enough to secure convenience or if one reading center is not enough, there should be an additional lamp or two. With the low ceilings found in many houses, it is impossible to put kerosene or gasoline lamps above the head because of the heat they radiate. This is unfortunate, for more lamps are required to light properly a room when the light sources are below eye level than when there is overhead lighting to give, if not all the light, the general background of illumination which is desirable. City dwellers and presumably rural people who use electric light suffer also from poor illumination, sometimes from insufficient light, and frequently from glare due to improperly shaded lamps (14, 16). If those who use kerosene and gasoline lamps learn to use them correctly, they will benefit by better lighting from these sources, and consequently by better eyesight (3, 4, 5, 7, 15) and by better health (1, 17, 20). Besides this, when electric light is made available for them they will be more likely to make proper use of it, for the principles of good lighting are the same no matter what is the source of illumination. 20 Nebraska Experiment Station, Bulletin 225 LITERATURE CITED 1. Abbott, Gladys: A Study of Posture in School as Affected by School Room Lighting. Amer. Phys. Ed. Rev., Vol. 10, p. 36. 1905. 2. Bell, Louis: The Art of Illumination. 2nd Ed. 1912. 3. Cobb, Percy W.: Some Experiments on the Speed of Vision. Ilium. Engin. Soc. Trans., Vol. 19, p. 150. 1924. 4. Cobb, Percy W., and Moss, Frank K.: The Effects of Brightness on the Precision of Visually Controlled Operations. Jour. Franklin Institute, Vol. 199, p. 507. Apr., 1925. 5. Cobb, Percy W., and Moss, Frank K.: Eye Fatigue and Its Relation to Light and Work. Jour. Franklin Institute, Vol. 200, p. 239. Aug., 1925. 6. Ferry, Ervin S.: General Physics. 1921. 7. Ives, James E., and Sydenstricker, Edgar: Studies in Regard to the Lighting of Postoffices, Made by the U. S. Public Health Service. Jour. Indus. Hyg., Vol. 8, p. 232. May, 1926. 8. Illuminating Engineering Society: Code of Lighting Factories, Mills, and Other Work Places. U. S. Bur. of Labor Statis., Bui. No. 331. 1923. 9. Illuminating Engineering Society: Code of Lighting School Build- ings. U. S. Bur. of Labor Statis., Bui. No. 382. 1925. 10. Kunerth, Wm.: Illuminating Power of Kerosenes. Iowa Engineer- ing Expt. Sta., Bui. No. 37. 1914. 11. Kunerth, Wm.: Lighting for Country Homes and Village Com- munities. Iowa Engineering Expt. Sta., Bui. 55. 1919. 12. Lansingh, V. R.: Walls and Floor, Their Effect on Lighting. Ilium. Engin. Soc. Trans., Vol. 15, p. 124. 1920. 13. Lansingh, V. R., and Rolph, T. W.: Some Experiments on Reflec- tions from Ceiling, Walls, and Floor. Ilium. Engin. Soc. Trans., Vol. 3, p. 584. 1908. 14. Luckiesh, M.: A Survey of Residence Lighting. Ilium. Engin. Soc. Trans., Vol. 17, p. 510. 1922. 15. Luckiesh, M., and Moss, Frank: The Rate of Visual Work on Alternating Fields of Different Brightnesses. Jour. Franklin Institute, Vol. 200, p. 731. Dec, 1925. 16. MacDonald, Norman D.: Lighting Statistics of Representative Urban and Suburban Homes. Ilium. Engin. Soc. Trans., Vol. 17, p. 488. 1922. 17. Ohm, J.: Kurze Darstellung der Ergebnisse meiner Augenzettern- forschung. Med. Klin., Vol. 21, p. 839. June, 1925. 18. Sharp, Clayton, and Millar, H. Preston: Illumination Tests. Illunu Engin. Soc. Trans., Vol. 5, p. 391. 1910. 19. Walsh, J. W. T.: Photometry and Illumination in Glazebrook. Dictionary of Applied Physics, Vol. 4, p. 410. 1923. 20. Westcott, Cassius D.: Eyestrain, Its Cause and How to Avoid It. Hygeia, Vol. 4, p. 44. Jan., 1926. [5M]