The clothing value or "warmth" of these substances as thus applied varies directly with these figures, representing the passage of heat or their "non-conducting" power.

The experiments described were directed to the determination of the relative power of different materials. (We have only quoted the substances most generally used for clothing purposes.) These were followed by another series upon certain given materials differently arranged, or in different conditions of density. The same "passage thermometer" was used. The question to be determined was, whether the protecting power of the substances used in the previous experiments was due to the non-conduction of the material of those substances themselves, or whether the air imprisoned between their fibres was an important factor. If the silk, wool and cotton did all the obstructive work independently of the air, then the amount of obstruction should vary with the quantity of fibre. As, in the experiments already described, the fibres were loosely arranged round the bulk of the thermometer, it was easy to increase their quantity by packing them more closely, and yet retaining the other conditions of bulk, etc., the same.

It was evident from the results, with 16 grains, 32 grains, 64 grains, that the protective power does not increase nearly in the same proportion as the quantity of material when packed in the same space. Had such been the case, and the rate of cooling proportionately retarded, the experiment (with eider down from the duck) with 64 grains should have been 1,304x4 5,216 seconds, instead of only 1,615 seconds.

The following displays the results obtained by using the same material, in same quantity, but differently disposed, 16 grains of each:

Heat lost or amount of coolingRaw SilkSewing or knitting silk wound round bulbSheeps wool, looseWollen thread wound round bulbCotton wool, looseCotton thread wound round bulbLinen, looseLinen thread wound round bulbLinen cloth wrapped round bulb
70°
6094"46"79"46"83"45"80"46"42"
501106295639560936256
401338511889117831158374
30185121162126152115150117108
20273191238200221179218180168
10489399426410378370376385338
Tot. times.1,2849041,1189341,0468521,032873786
Heat lost or amount of coolingRaw SilkSewing or knitting silk wound round bulbSheeps wool, looseWollen thread wound round bulbCotton wool, looseCotton thread wound round bulb
70°
6094"46"79"46"83"45"
501106295639560
40133851188911783
30185121162126152115
20273191238200221179
10489399426410378370
Tot. times.1,2849041,1189341,046852
Heat lost or amount of coolingLinen, looseLinen thread wound round bulbLinen cloth wrapped round bulb
70°
6080"46"42"
50936256
401158374
30150117108
20218180168
10376385338
Tot. times.1,032873786

From this it is to be seen that sheep's wool loose would retard the passage of heat more perfectly than when spun into thread.

The "Jaros Hygienic Material" of sheep's wool unspun worn next the body possesses the essentials for non-conduction of heat in a manner described.