622 
teriologists, there may be determined quite accur¬ 
ately the approximate number of bacteria which 
may be carried by an object. Some experiments 
recently carried out along this line have shown that 
during Summer weather a single fly from filthy sur¬ 
roundings may carry, at one time, as many as six 
million, six hundred thousand germs. What possi¬ 
bilities for spreading disease if these happen to be 
of a danger6us variety! 
Granting, then, that flies may carry multitudes 
of bacteria, the all-important question becomes, 
“Do they have access to the kinds that cause dis¬ 
ease?” Unfortunately, the evidence is positive that 
not infrequently they do have such access, and the 
menace for their presence lies in the fact that there 
is nothing in the appearance of the fly which comes 
so blithely to sup with you, to indicate whether it 
has just fed upon some festering sore, or the dis¬ 
ease-laden discharges of a typhoid patient, or 
whether it has merely been feeding on some attrac¬ 
tive bit of putrescent or decaying animal or plant 
matter. 
It is as a carrier of typhoid fever that the evi¬ 
dence against the house-fly is the strongest. It is 
now known that this disease cannot arise spontane¬ 
ously, but that every case is caused by infection 
with germs derived from some previous case of 
typhoid fever. These germs are contained in the 
excrement discharged by those sick with the dis¬ 
ease. Flies attracted to these discharges become 
thoroughly laden with the germs and then may 
transport them to substances which are used as 
food by man. Thus, wherever human excrement is 
exposed, as it is in open privies, or otherwise openly, 
both in the country and even in the alleyways of 
our cities, it may be not only a nuisance but an 
absolute menace to the health of the community. 
The most insidious danger lies in the fact that 
the typhoid germs may persist and be discharged 
PAD ON PLY’S FOOT. Fig. 265. (Magnified 375 Times.) 
from a patient long after he is apparently well. 
Moreover, the many mild cases, and cases of “walk¬ 
ing typhoid” are just as capable of discharging 
living typhoid bacteria as are the bed-ridden, and, 
being less under control, they are vastly more dan¬ 
gerous to the community. When we consider the 
readiness with which flies are attracted to filth, and 
the freedom with which they have access to foods, 
it is not surprising that studies have shown a very 
direct relation between the maximum occurrence 
of typhoid and other intestinal diseases, and the 
period of greatest abundance of these insects. So 
conclusive is the evidence against Musca domestica 
that Dr. L. O. Howard, in a recent publication, 
proposes to substitute for the common name “house¬ 
fly,” that of typhoid-fly. While, of course, other 
insects may serve to disseminate this disease, the 
house-fly is the one which so predominantly comes 
into contact with man that the proposed name may 
serve a useful end in emphasizing the dangerous 
possibilities of this pest. 
We have spoken of the relation of the occurrence 
of other intestinal troubles to the periods of greatest 
abundance of flics. These diseases, like typhoid, 
are due to specific germs which are abundantly 
contained in the excrement of diseased individuals. 
Equally readily with typhoid they may be trans¬ 
mitted by any insect which has access to infected 
feces. Indeed, the chances for such accidental 
transmission are even greater, since several of these 
diseases are diseases of childhood, and children are 
not only less likely to be careful in their habits, but 
are less particular as to the cleanliness of what they 
eat. .But the list does not end here. It is well 
known that flies feed readily on sputum, and, there¬ 
fore, if this be ffoin a tuberculous, patient, it is a 
foregone conclusion that the insects may carry 
about the bacilli of tuberculosis. Many experi¬ 
ments have shown that these germs are capable of 
remaining alive for an extended period. Thus, 
under appropriate conditions, our house-fly may 
become a factor in the spread of the white plague. 
In the instances cited, the disease germs are de- 
THE RURAL* NEW-YORKER 
posited on food, or utensils, and only indirectly 
infect man. Another type’ of diseases may be pro¬ 
duced directly by the fly’s conveying to wounds, 
or abrasions of the skin, the germs of tetanus, or 
lockjaw, or of splenic fever, or the pus-producing 
bacteria which may render futile the most care¬ 
fully performed surgical operation. 
The dangerous character of this household pest 
once clearly recognized, there can be no question as 
to the attitude we should assume towards it. A 
disease carrier, it must be rigidly kept from articles 
of food. The candies, cakes, and other delicacies 
exposed in our stores and markets become more 
than mere collectors of dust and dirt—in the hot 
Summer months they are the favorite resort of 
what one writer has so aptly termed “the fly that 
doesn’t wipe its feet.” From private houses it 
may be practically excluded by screens and by 
care not to leave exposed substances which will 
LARVA OF COMMON HOUSE FLY. Fig. 2G6. 
attract it. But efficient measures must be more 
far- reaching than this. The original sources must 
be eliminated. It is already the practice of all 
competent physicians to require the disinfection of 
disease-infected discharges of patients. This 
should be universally insisted .upon, but even this 
does not obviate the danger from unrecognized, or 
incipient cases, or from convalescent and sup¬ 
posedly harmless cases. The dangerous open privy 
should be entirely abolished, or where this is im¬ 
possible, it should be carefully screened, and, as 
partial aid, deposits covered with lime. And, finally, 
the fly must be attacked in its breeding places. 
It has already been stated that it breeds primarily 
in horse manure. In addition, it may also breed in 
kitchen refuse and even in decaying vegetable 
matter. Such material should not be allowed to ac¬ 
cumulate. Exposed manure heaps should either not 
be tolerated in cities, or, since during warm 
weather, about eight to 10 days are required for 
development from the egg to the perfect fly, the 
manure should be carted away, or disinfected, every 
week, thereby destroying the pest in its younger 
stages. This means some trouble and inconveni¬ 
ence to the owners of stables, but the gain to the 
community, even in the matter of relief from an¬ 
noyance, would repay it, and when we consider 
the relation of such measures to public health, their 
disregard becomes nothing less than criminal care¬ 
lessness. w * A. RILEY. 
Cornell Experiment Station. 
A WATER POWER FOR ELECTRICITY. 
I have an old mill privilege; formerly used to run .an 
up-and-down board saw and a shingle saw. Plenty of 
power was produced to run a night and day crew from 
December to May. Of course, there is a very little water 
running during the Summer, but I think 1 could easily 
raise the dam a little and flood a 20-acre meadow. The 
dam at present time is IS feet wide and has a fall of 20 
feet. I am wondering if there is power enough to pay to 
put in a turbine wheel and a dynamo, and get sufficient 
electricity to pump water from my artesian well, grind 
fodder, saw wood, etc., also light my home town of 2,000 
Inhabitants. i. c. 
Meriden, Conn, 
There is no question whatever that with a fall as 
• 
great as 20 feet, a v£ry moderate stream of water 
will give sufficient power to light the farm buildings 
and do all the ordinary work requiring power, such 
FOOT OF A FLY. Fig. 267. 
as grinding feed and the like. For example, tinder 
a head of 20 feet, one acre of water one foot deep 
will, if properly utilized, furnish from 10 to 12 horse¬ 
power for about 10 hours, or it would give four or 
five horse-power throughout the whole day and 
night. When we enter into a discussion as to the 
feasibility of developing a water power to the extent 
of lighting a village of 2000 inhabitants, the propo¬ 
sition immediately becomes more complex, and one 
would not be justified in undertaking or beginning,it 
without consulting a good hydraulic engineer. In any 
case the. cost of installing a plant will vary within 
very wide limits, depending upon the condition of the 
present old dam, and amount of excavation neces¬ 
sary in order to secure a suitable “tail-race,” and 
the distance which it wil] be necessary to carry the 
current. This last factor will have a most important 
bearing upon the question of the type of electric 
June 26, 
machinery to adopt. It may be well to remember 
that it is not safe to calculate on more than 10 or¬ 
dinary 16-candle-power carbon lamps for each avail¬ 
able horse power. The new type tungsten lamp, 
which is rapidly being introduced, gives a much 
higher efficiency than this, however. One village 
with which I am familiar, with a little more than 
2000 inhabitants, uses well toward 100 horse-power in 
the early evening when carrying the “peak” of the 
load. After 10 o’clock in the evening, however, the 
power required is hardly more than one-quarter of 
this. So in village plants, it frequently happens that 
the water power and steam can be used to supple¬ 
ment each other very nicely. I certainly feel that 
any considerable stream with a head of 20 feet and a 
dam already in position is well worth considering. If 
one were given the distance from the house to the 
power and the amount of power that it was desirable 
to develop, it would be easy to give some fairly de¬ 
pendable figures as to the cost of water wheel, gov¬ 
ernor, dynamo and copper wire. The cost of in¬ 
stalling the power, however, is the most variable 
question, and this could only be determined by an in¬ 
spection of the site. jared van wagenen, jr. 
PLANK STALL WITH CONCRETE BOTTOM. 
In regard to your plank floor for horse stalls with 
cement bottom, page 563, would add that I built one, 
which has proved satisfactory, in the following man¬ 
ner: .1 used 2x4-inch, six feet long, laid flat. I 
bored one-half-inch holes through the planks edge¬ 
wise and strung the planks on three half-inch rods, 
having heads on one end and threads and nuts at the 
other end, one bolt through the center and one near 
each end. Planks were spaced one-half inch apart, 
FEMALE COMMON HOUSE FLY. Fig. 268. 
with several ordinary washers. I drew the planks up 
tight with the nuts and hung the floor thus formed on 
T hinges to side of stall, and provided a strong ring 
for raising. By lifting up the slat floor and holding 
it raised by a suitable snap hook caught into the ring, 
the concrete floor can be cleaned or flushed out with 
water and the spaces between the planks can be 
easily raked out with a hook, such as every stable 
usually has for raking out the hoofs of horses. The 
cost of the bolts and washers, which were obtained 
from a local blacksmith, was 75 cents, and the small 
extra labor involved was more than compensated for 
by the sanitary condition of the stall. I do not find 
it necessary to raise the floor to clean more than 
once or twice a week, as the drainage is fairly good. 
The width, four feet six inches, in the clear between 
partitions, is about right. Between four feet six 
inches and five feet in width a horse is more liable 
to get cast. f. e. b. 
Connecticut. ,_ 
With the present high prices for grain, it is worth 
dollars to know what feed contains. This is when 
the scientific study of a “balanced ration” makes 
money for a feeder. It all comes down to the fact 
of knowing where to go to buy protein, carbohy¬ 
drates, or fat at the lowest price per pound. We 
cannot do this until we can figure out a ration. We 
still find it best economy to buy the entire grains 
and grind at home. 
The English courts have just settled a patent case 
of some importance. In 1900 a patent was granted 
for making stone tiles. Instead of starting the in¬ 
dustry in England the patentee sold rights to work 
his patent in France, Germany and Belgium, from 
which countries the goods were brought to British 
markets. Under the English law a patent must be 
worked in that 'country or a satisfactory reason 
given for not working it. In the case of these stone 
tiles no good reason was given, and therefore, the 
patent was revoked and the process made free to 
all. The law was intended to aid English manufac¬ 
turers. 
