the pillow 1 of the preferred embodiment as illustrated in fig1 has a longitudinal side 2 and a transverse side 3 ( the other longitudinal side and the other transverse side not being apparent in fig1 ). the upper surface 5 of the pillow 1 is shaped such that the longitudinal cross - section of the pillow is substantially constant . the transverse side 3 is preferably approximately 330 mm long and has an appreciable vertical extent 6 ( unlike conventional pillows which have negligible vertical extent at their transverse side ). in addition , the upper surface 5 is formed with a crest 8 which is located closely adjacent the transverse side 3 . moving away from the crest 8 in a longitudinal direction towards the other transverse side , the upper surface 5 falls away . the longitudinal side 2 is approximately 590 mm in length and substantially vertical . the longitudinal side 2 has substantially the same appearance as any longitudinal cross - section through the pillow 1 . this is in marked contrast to conventional pillows where the longitudinal sides are substantially merely an edge . preferably the pillow 1 is formed from two , or even three , layers of foamed plastics or other elastomeric materials , such as polyurethane or latex , which preferably have different densities . as seen in fig2 , a user 10 is depicted sleeping on a mattress 11 having a surface of negligible resilience or “ give ” and is also depicted sleeping on his side . it will be seen that the lower shoulder 12 of the user 10 either abuts , or is closely adjacent to , the transverse side 3 . the crest 8 supports the neck of the user , in particular in the region between the ear and the shoulder . the upper portion of the head , in particular above the ear , is supported by the sloping surface of the pillow 1 which faces away from the shoulder 12 . an important advantage obtained by the pillow 1 is that the crest 8 , in particular , supports the neck and lower head and thus the neck muscles are , in large part , relieved of this obligation . in addition , as indicated by broken lines in fig2 , the lower shoulder 12 in practice at least to some extent , sinks into the mattress 11 or other supporting surface of the bed on which the user is sleeping . it is also desirable to gauge the resilience or firmness of the mattress so that this can be taken into account in assessing the effective vertical depth of the shoulder 12 in the sleeping position illustrated in fig2 . in order to assist the user 2 to carry out the requisite measurements on himself , a generally l - shaped measuring device 20 as illustrated in fig3 is provided . the device 20 has first and second edges 21 , 22 which are substantially mutually perpendicular and each of which is provided with a ruled scale , preferably having two series of indicia . the first series of indicia is a conventional numerical scale and the second series of indicia is a mirror image reversal of the numbers of that scale . as a consequence of the mirror image reversal of the numbers of the scale , a user 10 can utilize the device 20 himself by standing in front of a mirror in order to measure the height of his head above the shoulder , and the horizontal extent from neck to shoulder . the shoulder width is the horizontal dimension from the user &# 39 ; s ear to the outside edge of the adjacent arm . the head height is the vertical dimension from the upper surface of the shoulder to the top of the head . by looking in the mirror , the mirror reversed numerals are again reversed and thus are readily legible to the user 10 . preferably the device 20 in addition to including instructions also includes an orifice 25 through which the user 10 may insert a thumb , for example , in order to assist the holding of the device 20 on the user &# 39 ; s shoulder in order to take the requisite measurements . the device 20 is preferably fabricated from cardboard and has the scale , numbers and instructions printed thereon . turning now to fig4 - 7 , a number of different pillows are illustrated in longitudinal cross - section . fig4 shows a conventional pillow 31 which has narrow transverse edges . fig5 essentially repeats the shape of fig1 and 2 and illustrates the shape of the pillow 1 suitable for persons who habitually sleep on their side . fig6 shows the shape of a pillow 41 suitable for a person who habitually sleeps on their back . it will be seen that the crest 8 is essentially reduced or abolished giving a generally level upper surface 5 . for those persons who sleep alternatively on their back and on their side , a pillow 51 of the shape illustrated in fig7 is best with a lesser crest 8 a than the crest 8 of fig5 . the inventor has observed that head size , and hence head weight , differs little from one individual to another , but that body size including shoulder width , and hence the weight which compresses the mattress 11 , varies to a very substantially degree from one individual to another . in response to this observation the inventor has developed a neck compression index ( hereinafter “ nci ”) which is the total weight of a person in kg divided by the width ( or sideways extent ) of the person &# 39 ; s shoulder in centimeters . thus a first person weighing 110 kg and having a slight build with a shoulder width of only 18 cms has a neck nci of 110 / 18 = 6 . 1 . similarly another person who weighs 95 kg and has a normal build with a shoulder width of 18 cm has an nci of 5 . 28 . conversely a 55 kg person with a shoulder width of 13 cms would have an nci of 4 . 23 . typically the nci is normally between about 3 and about 8 . the nci provides an indication of the degree of pressure or force to which the pillow is subjected during sleep . the lower the nci the less the density and / or hardness of the pillow which best matches the user &# 39 ; s physique . a very small percentage of the human population has either very long necks or very “ tall ” heads ( or both ) and thus need a pillow which is lengthened in the head to toe sleeping direction . the advantage of measuring the head height by the device 20 of fig2 is that it enables this small percentage of the population to be accorded the different treatment they require . the nature of the mattress is also preferably taken into account . for example , a very soft mattress compresses under the weight of the sleeper to an appreciable extent below the undeformed upper level of the mattress , for example by as much as 15 cm . therefore before the neck compression index is calculated the shoulder width should be adjusted to account for the nature of the mattress . furthermore , a pillow top ( an additional layer of padding ) can reduce the shoulder width by from 2 - 5 cms . these adjustments are summarized in the following table . that is , using the adjusted shoulder width an nci can be calculated which is compensated for the nature of the mattress ( and also any pillow top ). turning now to the pillow , different manufacturing techniques have different ways of measuring the resilience of the pillow . for latex pillows there is a standard referred to as “ indent deflection loading ” ( hereinafter “ idl ”) which utilizes the pressure or weight required to compress by 40 % a block of foam typically one foot by one foot in area to be compressed and eight inches thick . very soft latex or foam pillows which compress to a substantial degree have an idl of typically 6 - 8 whereas “ hard ” latex or foam pillows which only compress a small amount have an idl of typically 10 - 15 . pillows made from polyurethane foam , or latex , use a different measuring criterion , namely the mass or density of the foam material expressed in kilograms per cubic meter . “ soft ” pillows are typically 50 - 65 kg / m 3 whilst “ hard ” pillows are typically 70 - 75 kg / m 3 . in addition , pillows made from polyurethane or latex foam use a still further standard rating which utilizes two letters and a pair of two digit numbers . “ soft ” foam pillows have a rating such as vf52 - 40 , or op35 - 110 or hf18 - 35 whereas “ hard ” foam pillows have a rating such as aa15 - 60 , or aa17 - 80 or lr38 - 40 . these figures need to be modified somewhat if the pillow is provided with an array of vertical holes ( e . g . 5 mm in diameter ) and / or horizontal channels , both of which reduce the effective hardness . with the above in mind it is possible to draw up a selection table which enables a pillow to be selected once the neck compression index , and preferably the compensated neck compression index , has been calculated . table ii is such a selection table . a preferred embodiment of the present invention is particularly applicable to accommodation establishments such as hotels , motels , and the like . such establishments pride themselves on offering their customers a good night &# 39 ; s sleep which naturally requires that the customer , mattress and pillow be matched to the maximum possible extent . this can be achieved in accordance with the preferred embodiment as follows . the accommodation establishment normally has a single type ( or a restricted number of types ) of mattress throughout all its bedrooms . thus the establishment can select , say , four different types of pillows which cover the expected range of uncompensated neck compression indices for substantially all their customers . these pillows are then placed in corresponding color coded pillow slips and all four types of pillows are provided for each bed in each room . in addition , each room is provided with the device of fig3 and instructions ( labeled personal pillow selection ) to the room occupant to use the device of fig3 to measure his nci . once this has been calculated it falls within one of the ranges of pillows and so the correspondingly colored pillow slip is determined and the correct pillow thereby selected . the uncompensated nci can be used because the nature of the mattress is known beforehand . in another embodiment , a mail order pillow purchasing business can be conducted in which the customers using a personal measuring kit determine their weight and their neck and head dimensions and supply these together with their details of their mattress to the vendor . the vendor then calculates the compensated nci and determines a suitable pillow which is then either fabricated or selected from the range of pillows on offer by different pillow manufacturers . in a still further embodiment , the mail - order pillow purchasing business can be conducted via a website and the internet . in particular , in this embodiment the device of fig3 is not required to be utilized by the prospective purchaser . instead , to ascertain the width of the purchaser &# 39 ; s shoulder , the purchaser uses a conventional webcam ( or camera able to take a photograph and send it via the internet to a distant destination ) to take a head and shoulders photograph 71 ( similar to a passport photograph ) of themselves as illustrated in fig8 . the photograph 71 is then transmitted to the website of the vendor and appears to the purchaser as illustrated in fig9 . the purchaser is then able to translate his image relative to two intersecting markers 72 , 73 illustrated by dashed lines in fig9 , thereby resulting in the situation as illustrated in fig1 . here the purchaser &# 39 ; s left ear is aligned with the vertical marker 72 , and the top of the shoulders are aligned with the horizontal marker 73 . this establishes the purchaser &# 39 ; s photograph in relation to a template stored in the computer which operates the vendor &# 39 ; s website . next the vendor displays on the screen , a marker line 75 indicating the horizontal distance to the right of a baseline 74 aligned with the purchaser &# 39 ; s left ear ( as seen in fig1 ), the marker line 75 initially being illustrated by a broken line . associated with the marker line 75 is a screen display 76 which displays a distance in centimeters which represents the length of the arrow extending from the baseline 74 to the marker line 75 . initially this distance in centimeters is , say , 15 cm . the purchaser then moves the marker line to the right as seen in fig1 so that the marker line 75 is flush with the left shoulder of the purchaser as indicated by a dot - dash line in fig1 . this causes the screen display 76 to increase to , say , 18 cm which is the width of the purchaser &# 39 ; s shoulder which is then either manually or automatically entered into the data being collected by the vendor and from which the neck compression index is to be calculated . as mentioned previously , the inventor has observed that head size differs little from one individual to another . this is supported by anthropometry studies such as those conducted amongst british navy personnel and reported in the book “ the measure of a man and a woman ” published in 2002 . consequently , it is known that for , say 99 % of purchasers , the length of the neck and head is the same and is approximately 27 - 28 cm . since the scale on the photograph is the same in the vertical direction as in the horizontal direction , an assumed head height of 27 . 5 cm enables the distance of the marker line 75 from the baseline 74 to be calculated with acceptable accuracy , and displayed in the screen display 76 . consequently , as the position of the marker line 75 is varied , so the calculated distance displayed in the screen display 76 is also varied , all based on the assumed height of the head and neck . the foregoing describes only some embodiments of the present invention and modifications , obvious to those skilled in the art , can be made thereto without departing from the scope of the present invention . in this specification , inferences to the masculine gender are to be taken to include the feminine gender , and vice versa . the term “ comprising ” ( and its grammatical variations ) as used herein is used in the inclusive sense of “ having ” or “ including ” and not in the exclusive sense of “ consisting only of ”. while the principles of the invention have been described above in connection with preferred embodiments , it is to be clearly understood that this description is made only by way of example and not as a limitation of the scope of the invention .
a neck measurement device and a method of selecting a pillow which takes into account the physique of the user are disclosed . a neck compression index is calculated being the weight of the sleeper in kilograms divided by the shoulder width of the sleeper in centimeters . preferably a compensated nci is calculated which takes into account the softness or hardness of the mattress . a pillow resiliency is then selected based on the nci . color coded pillow slips can be used to assist sleepers to self - select a pillow appropriate for their physique . mail order and internet based selling methods are disclosed .