112 



HULES FOR INVENTION. 



VII. It will bake, roast, and boil, equally well with the 

 common tin-plate stove, as it has a capacious oven. 



VIII. In consequence of these philosophical improvements 

 it requires not more than half the usual quantify of fuel*. 



Ex. 4 Art of Example IV. The art of hulling and cleaning rice. 



hulling nee. r o & 



Pri//W/</. . The Step 1. The principles on which this art may be founded, will 

 cuter coat of appear by taking a handful of rough rice, and rubbing it hard 

 sharp, and the between the hands j the hulswill be brushed off, and by con- 

 surfaces if rinuing the operation, the sharp texture of the outside of the 

 ther, cut°each nu ^ (which through a magnifying glass appears like a sharp 

 other. fine file, and no doubt is designed by nature for the purpose) 



will cut off the inside hull j the chaff being blown out, will leave 

 the rice perfectly clean, without breaking any of the grains. 

 II. What is the best plan in theory for effecting this*? 

 Plan for prac- jjr^ The disadvantages of the old process are known to those 



who have it to do. 

 Art of prevent- Example 5. To save ships from sinking at sea. 

 ing ships from Step 1. The principles on which ships float, are the differ- 

 Prin ip'lrs. ence of their specific gravities, from that of the water, bulk for 

 why bodies bulk, sinking only to displace water equal in weight to the 

 a popular way .ship; therefore, they sink deeper in fresh than in salt water. 

 If we can calculate the cubic feet a ship displaces when empty, 

 it will shew her weight, and subtracting that from what she 

 displaces when loaded, wiil shew the weight of her loaded. Each 

 cubic foot of fresh water being 625lbs. if an empty rum hogs- 

 head weigh 62 , 5lbs. and measure 62 cubic feet, it will require 

 875"lb. to sink it. A vessel of iron, &c. filled with air, so large 

 as to make its whole bulk lighter than so much water, will 

 float j but if the air be let out and filled with water it will sink. 

 Hence, we may conclude, that ships loaded with any thing that 

 will float will not sink, if filled with water ; but, if loaded with 

 any thing specifically heavier than water, will sink as soon as 

 filled. 



II. This appears to be a true theory. — How is it to be put in 

 practice, in case a ship springs a leak that gains on the pumps ? 



* The discription will appear in a future number of our Journal. 



+ He describes a machine, which likewise deserves to be attended to, 

 though less immediately connected with the industry of Great Britaiu. 

 I shall consider it, W. N. 



HI. 





