I governed the machine which keeps her ballanced between two waters. With the bathomater before me And with one hand I found I could keep her at any depth I thought Proper the men then commenced movement and continued about 7 Minuets when mounting to the Serface I found we had gained 400 Matres. I again plunged turned her round under water and returned to near the Same place. I again plunged And tried her movements to the right and left, in all of which the helm answered And the compass acted the same as if on the serface of the Water having continued these experiments the 8, 9, 10 and 12th untill I became fameliar with the movements And confidence in their operation, I turned my thoughts to Increasing or preserving the Air, for this purpose the Cn. Gueyton advised to precipitate the carbonic acid with lime, or to take with me bottles of Oxizine which might be uncorked as need required; but as any considerable quantity of bottles would take up to much room, And as oxizine could not be created at Sea without a Chymical operation which would be Very Inconvenient, I adopted a mode which occured to me 18 months ago which is a Simple Globe or bombe of copper capable of containing one cube foot to (Manuscript is torn here) A Pneumatick Pump by means of which Pump 200 Atmospheres or 200 cube feet of common Air may be forced Into a Bomb consequently the Bomb or reservoir will contain As much oxegine or Vital air as 200 cube feet of common respirable Air, hence if according to Cn. Gueyton’s Calculation 212 feet which is the Volume of the boat will nourish 4 Men and two small candles 3 hours this additional reservoir will give Suffecient for 6 hours—this Reservoir is constructed with a measure and two cocks So as to let measures of Air Into the Boat as Need may require require— Previous to my leaving Paris I gave orders for this machine but it did not arrive till the 18 of thermidore on the 19 I ordered 2 Men to fill it which was an operation of about one hour I then put It into the boat and with my three companions but without candles plunged to the depth of about 5 feet, At the expiration of one hour and 40 Minuets I began to let off Measures of air from the reservoir and So on from time to time for 4 hours 20 Minuets without experiancing any Inconvenience— Having thus succeeded To Sail like a common Boat To obtain Air And light To Plunge and rise Perpendicelar To turn to the right and left at pleasure To steer by the Compass under Water To renew the Common Volume of Air with facility