16 [ ASSEMBLY 
experiment upon the evaporation of water from the freshly cultivated 
and ordinary surface soil of our cornfield. This experiment, reported 
in our bulletin No. V, is here reproduced: 
The question of drouth is one which periodically engages attention, 
and any means by which its injurions effect may be mitigated should 
certainly be known to the farmer. That cultivation by forming a 
loose soil upon the surface, which acts as a mulch, conserves the water 
to the soil, is a fact which is well established, and should be more 
commonly appreciated. For the purpose of offering numerical values 
which shall express the influence of cultivation, we have tried the 
following experiment: Oak boxes of one cubic foot capacity were 
made of half-inch stuff and thoroughly soaked with oil. ‘The bot- 
toms being removed, the frame was forced down into the earth in the 
cornfield, and the bottoms afterward put in position.. We thus had a 
foot cube of soil in its natural position. ‘The surface of the earth in 
one box was left undisturbed, while the surfaces of two boxes were 
kept cultivated. By weighing these boxes, the gain or loss in weight 
is assumed to measure the evaporation which has taken place from 
each. From July 26 to August 1, six days, the cultivated soil evapo- 
rated at the rate of 906 gallons per acre less than the undisturbed soil, 
or less 151 gallons daily per acre. From August 1 to August 10, 
nine days, the cultivated soil evaporated 2,367 gallons per acre less 
than did the undisturbed soil, or less 263 gallons daily per acre. Dur- 
ing the whole period from July 26 to August 10, fifteen days, the 
saving of water effected through cultivation figured up 212 gallons 
daily per acre, or, expressing these facts in another form, the undis- 
turbed soil lost per acre from July 26 to August 10, 4,243 gallons, the 
cultivated soil 1,060 gallons. 
In calculating our results to the acre by multiplying the evaporation 
which has taken place from a square foot of surface by 43,560, the 
unayoidable errors are correspondingly multiplied, and while duplicate 
series can never be expected to give precisely the same numerical 
results, yet the one fact becomes unquestionable, that through culti- 
vation we are enabled to conserve to the soil a large amount of water 
during adrouth. Indeed, observation through extended periods of 
drouth also plainly shows the superiority of fields that have been well 
cultivated, over those where cultivation has been neglected. 
THE LABORATORY. 
The former parlor of the dwelling has been fitted upas a laboratory, 
and the fretted ceiling and handsome white marble mantels add much 
to the attractions of the apartment. The wall spaces are all occupied 
with closets, cupboards, shelves and tables. ‘The working tables are 
supplied with numerous gas and water jets, with sinks, ete., in the 
positions required for convenience. In the north-east corner large 
drying ovens of copper have been put in position and are kept hot by 
the use of steam from the boiler in the room below; next to this isa 
hood, connected with the chimney by a long narrow opening, and 
fitted with steam jets for use in evaporating, and with water and gas, 
Above these arrangements is fitted a brass and block tin condenser, 
which taking steam from the drying oven jacket condenses it into dis- 
