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164
Seats and
desks.
Annual Report of the London County Council, 1911.
The water has a depth of 5 ft. 4 ins. at one end and 4 ft. at the other. The bath-room is
roofed in, and is ventilated on the North and East sides by wooden louvred shutters. Each Saturday
it is emptied, scrubbed out, and sometimes acid is used to clean the tiles. On Monday mornings it
is filled by 4,300 gallons of water. The temperature of 60° F. is generally maintained by blowing in
steam, and in cold weather the temperature is raised to 70° F. Batches of a dozen boys, after having
washed over with soap and water, are allowed to bathe daily, remaining in as long as half-an-hour. If
the bath is used twice daily the water is renewed in the middle of the week as well. Specimens of the
water were bacteriologically examined on a Monday, before the bath had been used, Wednesday, and
Friday, and of the sediment left on emptying the bath on Saturday.
On the Monday counts showed only about 100 organisms to the cubic centimetre—a satisfactorily
low degree of bacterial contamination of the fresh bath water. The colonies obtained all appeared to
belong to the Proteus group, and the presence of Bacillus coli could not be detected.
On the Wednesday, the temperature, 70° F., was somewhat higher, so that the comparison with
the other examinations would not be strict. The contamination was approximately 4,000 organisms
to the cubic centimetre. Various cultures of the Proteus, notably Proteus Zenkerii, were obtained.
Staphylococcus epidermidis albus and S. Pyogenes aureus, Sarcina lutea, Streptococci of the S. brevis
fæculis type, and diplocci of normal saliva were determined. Flasks inoculated with 50 c.c., 20 c.c.,
10 c.c., and 5 c.c. of water also yielded B. coli communis.
On the Friday, the fifth day on which the water had been used but the temperature had not been
raised above 60°, a contamination of about 1,200 organisms per cubic centimetre was determinedSome
leptothrix and the organisms above mentioned were determined with the exception of B. coli
communis.
In the deposit from the surface of the bath after running off the water all these organisms were
present, notably the Proteus and B. coli group.
On reviewing the nature and numbers of organisms found at different times, it may be observed
that they are such as would be most likely to occur, but the presence of B. coli communis and S.
fæculis suggest the possibility of the bath being a possible medium of infection in cases of epidemic
enteritis, or even in the event of its being used by a typhoid carrier, the possible transfer of B. typhosus
In addition, the presence of organisms commonly found in the mouth indicate the possibility of the
transmission of infective conditions of the mouth and throat. The largely increased number of
organisms found during the week when the bath was being used at a temperature of 70° F. instead
of 60° F. also suggests more frequent renewal of the water under such circumstances.
In the Report for 1909 the attitudes of children writing in class were discussed; further
questions, however, in relation to the seats and desks for elementary school children were
omitted. In large towns fitting and furnishing has to be controlled by the cost of materials
and dearness of land. This does not concern the solution of problems which present themselves
to the hygienist. He must consider first how to fulfil sanitary conditions, and having defined
these requirements, they can be modified to practice, and the best compromise between economy and
efficiency obtained. Space is the main requirement in school, or, indeed, in the lives of children in
large towns. The minimum school space allowable by the Board of Education regulations has become
the maximum permissible. Certain needs restrict, others would extend the dimensions of a class-room.
The class must be well within range of the ordinary voice of the teacher. Normal children in quiet
outside air respond to the forced whisper up to eighty feet, but one-third of the Whitechapel children
under the best conditions obtainable in their schools fail with the test at twenty feet. It is, therefore,
apparent that without straining the child's attention or the ordinary voice of the instructor, a greater
distance from the teacher of about twenty to twenty-four feet would not be permissible. This gives
a limit of twenty five feet for the length of an ordinary class-room. Such a distance also falls within the
limits for visual acuity, allowing for the large percentage who fall short of normal vision.
The width of the room will be determined by the range of effective daylight; this depends on
the height of the windows, which again are restricted in extent by the requirements of heating and
ventilation. Class-room height above fourteen feet may be taken as ineffective for ventilation, and
if windows are carried close to the ceiling, there is a limit to the position of any sufficiently lighted
desk of about 21 feet from the window. If a gangway is allowed next the remote wall, this gives a
maximum width for the room of twenty-two and a half feet.
The angle of lighting is commonly said to be insufficient when from a desk the top of the window
subtends less than 25° with the horizontal. With a window 13 feet high this occurs at 22 feet on a
desk 3 feet high.
With a class room of the size 25 ft. by 22.5 ft. by 14 ft (=7,875 cub. ft.) the number of children
who could be accommodated depends on the sufficiency of the ventilation. Under the present regulations
of the Board of Education, such a room accommodates fifty-six children ; the exact number
depending probably on the desking. Nearly all elementary class rooms present the exhausting
bouquet d'enfant. School baths would do something to relieve this, but sufficient ventilation is more
important. The British Association Committee on School Ventilation decided that 3,000 cubic feet
of air per head per hour was advisable. If half that amount is taken as sufficient, then with seven
changes an hour, which, unless mechanical ventilation is resorted to, is all to be relied on as possible
in school under English climatic conditions, x the number of children who could be sufficiently ventilated
would be x; x 1500 = 7875 x 7, whence x = 37.
The educational size of classes has recently been fixed for the next generation as forty, and this
number may also be taken as the greatest number which could be instructed under healthy conditions
in the class room, whose limiting dimensions have already been fixed. Hygienic considerations of the
maximum space therefore coincide with educational in limiting the class size to forty pupils.